CN216155687U - Grass-type lake regeneration system - Google Patents

Abstract

The utility model provides a grass type lake regeneration system, which is characterized in that: including lake low reaches algae-containing muddy water multiple spot water intaking system, bank base materialization processing clean system, clear water pipeline transport upper reaches multiple spot still lake system that connect gradually to and the ecological steady extended system of grass type water and supporting auxiliary system, five subsystems run jointly: the algae-containing turbid water is extracted from multiple points at the downstream to a water treatment facility of a lake bank water source plant, and is subjected to purification treatment by a physicochemical method to obtain clear and transparent oxygen-enriched clear water which is delivered to the upstream lake bank through a pipeline for a long distance, and is returned to the lake at multiple points in a waterfall water landscape mode, and the ecological purification of an expansion system is added, so that the regeneration of the grass-type lake is finally realized. The utility model can synergistically reduce lake pollutants, has high water circulation energy efficiency, easy survival of aquatic weeds, luxuriant submerged vegetation and healthy and stable water ecology, and has self-regulation and anti-pollution buffering capacity.

Description

Grass-type lake regeneration system

Technical Field

The utility model belongs to the technical field of lake pollution treatment and regeneration, and particularly relates to a grass type lake regeneration system.

Background

China has 1km in total²2759, most of which are semi-closed fresh water lakes. In three and four decades, with the rapid development of socioeconomic properties, cities and towns around lakesThe stimulation is promoted, the human activities in the lake river are intensified, the continuous and accumulated pollution touches eyes and surprises, the original ecological system of the lake is completely destroyed, particularly, famous lakes such as Taihu lake, nest lake and Dian lake die when the blue-green algae bloom breaks out, the aquatic plant is sharply reduced, the water body is just like green oil paint, the water works (such as Wuxi, Wuhan east lake) taking the lake as the water source are forced to reduce the production and even stop the production or transfer other water sources (such as Dian lake), the living environment of people is deteriorated, and the life quality and the physical and mental health of people are seriously influenced.

In recent years, by vigorously constructing lake-surrounding sewage intercepting pipelines and sewage treatment plants, finely controlling the non-point source pollution of a drainage basin, forbidding a phosphorus-containing detergent and the like, widely applying the construction concept of sponge cities, even constructing large-scale primary rain regulation and storage treatment facilities, actively constructing large-area riverbank and estuary wetland of riverbanks and estuaries, implementing dredging of bottom mud of rivers and lakes, constructing ecological embankments, replacing fish culture in net cages of lakes, cooperating with the ecological water diversion, water replenishing, dilution, water changing, ecological restoration and other work of lakes, and by constantly implementing the systematic comprehensive measures, the trend and the degree of lake pollution are greatly twisted and lightened, and the lake water quality is favored to be changed, however, the good states of clearness, water grass swaying and shallow fish flying before pollution damage are really recovered, and the practice for many years shows that the effect and radical cure are still difficult to achieve only by means of the existing systematic treatment technical measures and management measures.

The root cause is: the total amount of pollutants entering the lake (including the amount of slow release of bottom sediment, and assumed to be a dimensionless value of 150 for easy understanding) greatly exceeds the current weak self-cleaning capacity of the lake (which is evolved into an ecological self-cleaning capacity assumed value 10 of an algae-type turbid water lake) and also obviously exceeds the ecological system self-cleaning capacity (assumed value 100) of a grass-type clear water lake 50 years ago (1970s), so that the ecological system of the lake is simply restored to an ecological health level (self-cleaning capacity 100) 50 years ago and is still insufficient to resist the current excessive total amount of pollutants entering the lake (150), and the most critical reality is that the intensity of human activities in the lake flow cannot return to a rare and pure natural state (100) 50 years ago and can be more than the total amount of pollutants entering the lake 50 years ago (possibly 200) and cannot be less (less than 100).

Therefore, powerful and continuously effective manual intervention measures must be established at present to gradually achieve the restoration of lake water ecology and the long-term maintenance of beautiful water ecology. If the self-healing capability of the lake or the self-cleaning capability after self-healing is only expected, and manual forced intervention is not added to enable the lake to be natural and natural, firstly, the process of realizing beautiful water ecology is too long (possibly needing tens of years or even hundreds of years), and secondly, the expected target can not be realized for a long time. This is probably a necessity of the development of economic society and also a necessity of one-way increase of human activities and higher requirements of people for beautiful life.

Therefore, the method has the reason that the healthy ecology of the grass-type clear water lake is successfully reproduced, and the feasible method for maintaining the healthy ecology is that manual forced intervention (dimensionless value is 140-50) and the healthy ecology of the lake (gradually regenerated from 10 to 100) are used for reducing more background pollutants (more than or equal to 150) of the lake; only by mutual cooperation, the beautiful scenes of clearness, water grass swaying and shallow fish flying can be smoothly reproduced and maintained for a long time.

In order to achieve the above-mentioned objectives, in recent years, in the fields of sewage treatment and environmental protection, watershed treatment and lake ecological restoration, research and attempts of two-phase combination of artificial forced intervention and natural purification of water ecology (the former is relatively active, and the latter is slightly passive) have been carried out, and some achievements and practical applications have been obtained, which bring hopes for a plurality of water bodies which have been developed into algae type turbid water lakes and transformation and recovery of the water bodies into grass type clear water lakes, but the methods and engineering technical measures have many defects and need more development and innovation.

In the patent application of the method for treating the polluted water quality of the lake or the landscape lake with low carbon and energy saving (the publication number is CN101913708B, publication date 2014.07.16, and the following is referred to as the prior art 1 for short), one or more solar aeration type oxygenation devices are arranged to oxygenate the water body and increase the water body circulation fluidity, and the polluted water quality is improved by manual forced measures and water ecological self-purification measures. Because the method needs to use more aeration type oxygenation equipment, the landscape water body looks more like a fishpond, so the popularization and the application are greatly limited, and the method (changed into a plurality of artificial waterfalls) is rarely adopted for the slightly larger lake landscape at present.

In patent application, namely a method for maintaining water quality and restoring ecology of lake landscape water (application publication No. CN106045213A, publication No. 2016.10.26, hereinafter referred to as prior art 2), an aeration biological filter bypass strengthening treatment system, an aquatic plant treatment system and a spherical carbon fiber combined filler treatment system are combined, the method has certain effect on small water and water without algae pollution, but the treatment efficiency is not high due to low water inlet concentration of the aeration biological filter, the ecological efficiency of the aquatic plant treatment system is low, so that the overall cost is high, the cost performance is insufficient, and the method is difficult to be applied to restoration of slightly large algae polluted lakes.

In patent application, a combined restoration method for eutrophic lakes (grant publication No. CN104512986B, publication No. 2016.12.07, hereinafter referred to as prior art 3), lake water is pumped by a water pump to a biological filter for treatment, then advanced treatment is carried out in an aeration biological nest, then natural sedimentation treatment is carried out, then the lake water flows back to the purification treatment of a flow making system, a biomembrane purification system, an aquatic ecosystem and the like which are composed of an aerator and a guide wall, and the lake water is pumped by the water pump to the biological filter for the next circulation. In view of the facts that a biofilter filled with zeolite molecular sieve filter materials is extremely easy to be blocked by biological viscous substances of water bodies, the naturally precipitated water bodies cannot reach the sufficient transparency required by submerged plants, and the overall relay flow effect of flow making of an aerator in a lake is marginal, the actual energy consumption is high, and the biofilter can be mistaken for a fishpond, the feasibility and the applicability of the combined restoration method are insufficient.

In the patent application, a method for repairing a degenerated lake (application publication No. CN106348449A, publication No. 2017.01.25, hereinafter referred to as prior art 4), a flocculating agent and a microbial agent are directly added into the lake, meanwhile, an artificial wetland is built on the coastal region of the lake and a method for repairing aquatic plants planted on the coastal region can really achieve short-term local effects, but the lake is not in an isolated static state, but is continuously input with exogenous pollution, so that the added preparation is difficult to continue for a long time, the added total amount of the preparation is huge, the microbial agent is difficult to become dominant strains in the lake and easy to lose, and water in the lake cannot exchange mass energy with the coastal wetland or plants, so that the lake state is difficult to change continuously, the repairing time is too long, and the true repairing can be difficult to achieve forever.

In patent application, a device and a method for rapidly repairing polluted water (application publication No. CN107445240A, publication No. 2017.12.08, hereinafter referred to as prior art 5), aluminum-iron mixed modified bentonite is sprayed on a large area of a water body so as to realize in-situ repair of the polluted water body, the water body repairing agent modified by a special method is said to improve the absorption capacity of the specific pollutant by multiple times, however, the bentonite adsorbed with the pollutant is settled into bottom mud, the pollutant is not degraded or moved out of a system, the more and more the bottom mud is accumulated, the more and more the pollution load of the water body is increased, and the adsorbed and settled pollutant is finally released back to the water body to form new superimposed pollution, so the method for directly adding the substance to the water body is classified as a temporary emergency measure, and treats both the symptoms and the root causes, but not a long term.

In patent application, "a lake treatment system" (No. CN106638458B, published 2019.02.05, hereinafter referred to as prior art 6), a floating zone is arranged on one side of a lake to form a river channel, a bottom impeller is used for generating lake circulating flow, an oxygen supply machine is used for increasing the oxygen content of a water body, and then the aim of micro-scale lake sewage treatment is achieved by combining with aquatic ecology such as aquatic weed planting and ecological floating islands. In view of the fact that the large water body of the lake is forced to circulate by the impeller, short flow is easy to happen, energy consumption is high, efficiency is low, and the actual circulation effect is greatly reduced, the final treatment effect is to be practically tested.

In patent application, "ecological restoration system for shallow polluted lakes" (No. CN211664912U, published 2020.10.13, hereinafter referred to as prior art 7), a healthy water ecological system is gradually constructed by gradually reducing pollutants and gradually improving water quality under the premise that the transparency of a water body and the external natural conditions are satisfied through a low sewage treatment structure, a seeding structure and a grass-type clear water structure. In view of the uncontrollable water transparency of the system and the fact that the pollutants are not subjected to forced circulation and effective mass transfer exchange in the three structures, the ecological restoration efficiency is flat, the application range is narrow, and the system cannot be directly applied to the turbid situation with high algae content in the water, an algae-water separation station (the conventional separation station is not thorough in separation, poor in effluent transparency, difficult in treatment of separated algae slurry and the like) needs to be built at the front end, and hydrodynamic improvement equipment (such as a water pump, a flow pushing machine, a wave surge machine and the like and limited in effect) needs to be arranged if necessary, so that the system is only a small part of an ecological restoration and regeneration system of a grass-type lake and needs to be supplemented and perfected by a large knife and broad axe.

In the patent application of water replenishing device and method for improving water quality of small and medium-sized lakes in polluted cities (application publication No. CN111943357A, published Japanese 2020.11.17, hereinafter referred to as prior art 8), polluted lake water is extracted and purified by an upflow anoxic/upflow aerobic biofilter, the lake is subjected to pollutant removal and then enters the lake as water replenishment, the method focuses on biochemical treatment of denitrification and dephosphorization by taking relatively low-concentration lake water as town sewage, and the anoxic/aerobic and internal reflux points are well known to be denitrification (namely a biomembrane method version of AO process known in the sewage treatment industry), and dephosphorization is smooth, and the total treatment efficiency is not high due to low inlet water concentration. Therefore, for the current algae-type turbid water lake with abundant blue algae caused by phosphorus pollution, the method has relatively weak functions of removing algae, turbidity and phosphorus, and is difficult to recover the water ecology in the lake as soon as possible to cooperatively play the function of the water ecology, so that the method has certain limitation.

In the prior patent technologies or the prior art, the bypass purification treatment is mainly performed by using a biological filter (classified as a biofilm method of a biochemical treatment technology) and assisted by simple physicochemical treatment technologies such as water oxygenation and low-efficiency circulation, and like the biological filter biochemical treatment technologies in the prior art 2, the prior art 3, the prior art 8 and the like, the technologies have no obvious advantages when being used for the algae-containing turbid water with lower nitrogen and phosphorus concentrations. Therefore, aiming at the defects of the various lake treatment and restoration systems and methods in the aspects of high-efficiency algae removal, thorough turbidity removal, forced phosphorus removal, continuous water pollutant reduction, low-energy-consumption oxygenation, energy-saving flow-making circulation and mass transfer enhancement, guarantee of survival and proliferation of introduced native submerged plants, forced bypass purification and water ecological natural purification cooperation, biomass utilization, system energy saving and the like, a grass-type lake regeneration system which is short in flow, simple and convenient to operate, stable for a long time, reliable in technology, easy to implement, low in total operation cost, standardized in operation, environment-friendly and the like is very necessary to be creatively and practically designed, the system has the advantages of mature and stable technology, low energy consumption, high efficiency, controllable pollutant reduction, easy survival of submerged vegetation and the like, can ensure that the algae-type turbid water lake is smoothly transformed into the grass-type clear water lake, can maintain stability for a long time after the transformation is successful, and has anti-pollution buffering capacity.

In a word, continuous innovation in the technical field of lake ecological reconstruction and regeneration and practical satisfaction of engineering and water ecological environment can be a long-term and arduous task. Meanwhile, the utility model has great generational significance, and has very obvious practical application value and socialist ecological civilization value.

SUMMERY OF THE UTILITY MODEL

In order to solve various problems and defects in the water ecological restoration and reconstruction technology in China, the grass-type lake regeneration system of the utility model does not continue to use the biochemical method (an activated sludge method, a biomembrane method and the like) commonly used for urban sewage treatment, does not adopt the method that the basic problems of ineffective' headache, headache and headache can not be solved by adding a certain specific functional preparation in the lake, designing streams in the lake, changing the aeration and oxygenation, pushing out various new salvage ships and special devices to salvage and filter blue algae and the like, but develops a new way, creatively adopts a cross-boundary key technology, namely the algae pollution water source physicochemical method purification and regeneration technology applied to the urban water supply (tap water) field, is the first cross-boundary technology from the water treatment (tap water) engineering technical field to the water purification and circulation water ecological reconstruction technical field, and is common, the system is classified into municipal water supply and drainage engineering technologies, and the system is classified into environmental ecology protection technologies, so that the lake regeneration system belongs to a cross-boundary transverse combination technology, and is a core innovation technology for obtaining oxygen-enriched clear water with extremely high transparency from upstream to lake to form a large circulation (similar to a huge 'artificial kidney') inside and outside the lake body based on mature technical means such as a high-efficiency and low-consumption physicochemical method, namely dosing coagulation sedimentation, air floatation algae removal, homogeneous filter material deep bed filtration and the like, and cooperating with dynamic lake water ecological reconstruction.

The utility model relates to a grass type lake regeneration system, which has the following general technical scheme:

the method comprises the following steps of extracting algae-containing turbid water from multiple points at the downstream of a lake to a water treatment facility of a bypass lake bank water source plant, carrying out physical and chemical purification treatment such as grid deslagging and water distribution, dosing coagulation precipitation, air floatation algae removal, turbidity and phosphorus removal, deep bed filtration of a sand filter and the like to obtain clear water which is rich in dissolved oxygen and has the transparency of up to 12m, carrying out long-distance purification treatment on the clear water to an upstream lake bank through a pipeline, returning the clear water to the lake at multiple points in the forms of a drop waterfall landscape and the like, enabling the clear water to gradually and naturally mix with original lake water (algae-containing turbid water) after entering the lake to form flowing live water in the lake to slowly flow to the downstream, and extracting more than or equal to 50% of the water flow when the clear water flows through a water intake section to perform the next round of purification cycle, thus repeatedly spitting out the clear water; meanwhile, in a sub-clear transparent area where the lake returning end of clear water is gradually enlarged, the biological diversity is constructed by introducing native submerged plants and/or pollution-resistant and pleased clear water plants and the like, the submerged plants and the like thrive under the conditions of underwater photosynthesis and the nutrition of nitrogen and phosphorus nutrients carried by water flow, the submerged plants gradually obtain advantages along with the open and durable running water circulation, the range of the grass-type clear water area is stably enlarged, and an aquatic ecosystem is restored to the strong natural purification capacity by matching with other ecological measures, so that the clear and beautiful grass-type clear water lake with shallow fish flight can be successfully reproduced.

A grass-type lake regeneration system is characterized in that: including lake low reaches algae-containing muddy water multiple spot water intaking system, bank base materialization processing clean system, clear water pipeline transport upper reaches multiple spot still lake system that connect gradually to and the ecological steady extended system of grass type water and supporting auxiliary system, five subsystems run jointly: the method comprises the steps of extracting algae-containing turbid water from multiple points at the downstream to a water treatment facility of a lake bank water source plant, purifying the algae-containing turbid water by a physicochemical method to obtain clear and transparent oxygen-enriched clear water, delivering the clear water to the upstream lake bank through a pipeline for a long distance, returning the clear water to the lake at multiple points in the forms of waterfall waterscape and the like, expanding ecological purification of plants and organisms in a system, continuously supplying live water in a self-circulation manner, and finally realizing regeneration of the grass-type lake.

The water intake system comprises a lake downstream or a main wind direction downwind position, and a plurality of water intake wells which are approximately equal in distance are arranged on a cross section vertical to the overall flow direction of the lake, a surface water intake is arranged at the top of each water intake well, the lower parts of the water intake wells which are partially positioned in deep water are close to a lake bed, and a lower water intake is arranged, each water intake well is sequentially connected through a lake bottom water conduit, and finally connected with a water intake pump room inlet positioned on the lake bank side, and the water intake pump room outlet is connected with a high-position grid water distribution tank positioned on the bank through a water intake valve flowmeter and a water intake pressure conduit.

The number of water intake wells is not less than 2, the number of surface layer water intake ports is not less than 2, and the number of lower layer water intake ports is not less than 1.

The purification system comprises a high-level grid distribution pool, the high-level grid distribution pool is sequentially connected with a coagulating sedimentation (clarification) air flotation algae removal pool, a homogeneous filter material air-water backwashing sand filter pool and a backwashing pump room through connecting pipelines, and the backwashing pump room at the rear end is connected with a buffering water suction well of the lake returning system through connecting pipelines.

The purification system also comprises a grid cleaner, a coagulant adding machine, a mud scraping and sucking machine, a finger-shaped water collecting tank and an air floatation algae scraping machine.

The lake returning system comprises a buffering water suction well, wherein the buffering water suction well is connected with a clean water pressurizing pump room through a pipeline, then passes through a clean water valve flowmeter, a combination well and an exhaust valve, and then passes through a long-distance clean water conveying pipeline to convey clean water to a lake returning water replenishing point at the upstream direction of a lake or a main wind direction upward to a lake bank.

The quantity of the clear water lake returning water replenishing points is not less than 5, and the water replenishing points are set into various forms of lake entering drop waterfall water scenes to continuously oxygenate the lake returning clear water of the water replenishing points.

The dissolved oxygen DO of the lake returning clear water is more than or equal to 5mg/L, the transparency is more than or equal to 12m, and the turbidity is less than or equal to 1NTU immediately before the lake returning clear water enters the lake.

The grass type aquatic ecology steady expansion system comprises native submerged plants introduced in a clear water area, emergent plants planted at shallow water and on the bank, ecological floating islands constructed at lakes and bays, other suitable floating leaf plants, native fries put in a proper amount, other suitable aquatic animals and insects, harvesting, fishing and other measures.

The auxiliary system at least comprises a power transformation and distribution room, a dosing room, a wastewater treatment and recovery system, a biomass carbonization workshop, a sludge deep dehydration/drying workshop, a laboratory/central control room and other facility measures, wherein the power transformation and distribution room provides power for power utilization equipment of a water taking system, a purification system, a lake returning system and the auxiliary system; the dosing room comprises: provides a prepared coagulant liquid medicine such as FeCl for a coagulating sedimentation (clarification) air floatation algae removal tank₃PAC and pressurized dissolved air; the wastewater treatment and recovery system comprises: the system is used for treating sludge discharge water of a coagulating sedimentation (clarification) air flotation algae removal tank and squeezed residual liquid of a sludge deep dehydration workshop, and recycling backwashing drainage water of a homogeneous filter material air-water backwashing sand filter after sedimentation treatment; the biomass carbonization workshop: the method is used for treating biomass residues such as algae slurry separated in an air floatation process, water hyacinth (water hyacinth) intercepted by a grid distribution pool, and decayed aquatic plants and the like fished/harvested in lakes, the organic biomass is crushed after being drained and extruded, and is fired at high temperature under the anoxic condition by adopting a high-pressure pressing machine-made charcoal process without using an adhesive to produce environment-friendly machine-made charcoal (a nationally recognized environment-friendly product) which can be used for living heating, barbecue, charcoal chafing dish and the like, so that the problem of final disposal and utilization of a great amount of daily biomass in lakes is fundamentally solved, the secondary pollution problem of the biomass is eliminated, and the worries of the prior art are relieved; the sludge deep dehydration/drying workshop comprises: used for deeply dewatering/drying the mud separated from the wastewater treatment system, and the dried mud cake contains a small amount of coagulant such as FeCl added in the production process except for a small amount of substances₃Most of the actual, PAC, is the forced removal from lakes of pollutants that have been converted to solid form, including organic pollutants (COD, etc.), nitrogen (N) phosphorus (P), colloidal pollutants, and SSEtc.; the laboratory/central control room and other facility measures including soft measures (software, management method) and the like provide guarantee for normal production and provide experience accumulation for continuous development

In the production process of the water taking system and the purification system, besides the main functions of algae removal, turbidity removal, phosphorus removal and the like, the water taking system and the purification system are required to be realized, the water taking system and the purification system are subjected to drop oxygenation for multiple times through a water taking weir at a water intake port on the surface layer of a lake, a water distribution weir of a high-level grating water distribution tank, a finger-shaped water collection tank, a water inlet and outlet water distribution weir of a homogeneous filter material air-water backwashing sand filter and the like, and pressurized dissolved air microbubble air floatation procedure of a coagulating sedimentation (clarification) air floatation algae removal tank is used for sequential oxygenation, the system realizes high-efficiency oxygenation on a water body under the condition that no special oxygenation power equipment is arranged, and the dissolved oxygen DO is more than or equal to 4-5 mg/L when clear water leaves a factory.

The fresh water from the lake returning system is conveyed to the lake bank in the upstream direction of the lake or the upward wind direction of the main wind in a pipeline mode, the point number of the water replenishing points of the fresh water returning to the lake is not less than 5, the waterfall water landscape of the water falling into the lake is set into various forms to continuously oxygenate the fresh water returning to the lake, and further, after the fresh water returning to the lake is continuously oxygenated, the dissolved oxygen DO (dissolved oxygen) just before being mixed with the lake water is not less than 5mg/L, the transparency is not less than 12m, and the turbidity is not more than 1 NTU.

The large circulation inside and outside the lake body is continuous slow flow running water circulation, the power depended by the circulation is one part of hydraulic lifting total power formed by the sum of a raw water taking pump of a water taking system and a clear water pressurizing pump of a lake returning system, and the value of the total power expressed by the pump lift of the water pump is less than or equal to 70 m. Furthermore, the total power of hydraulic lifting can be that the water taking pump is lifted once and then gravity flows automatically, or that the water taking pump is lifted twice after pressurizing, and the determining factor is the terrain elevation of the purification treatment facility.

In the technical design and production process of the water taking system, the purification system and the lake returning system, water flow drop is oxygenated, the oxygenation effect is better than weir crest free flow, the flow is submerged, the ventilation at the water drop is emphasized, and the influence on oxygenation caused by closed shielding or unsmooth ventilation is avoided.

The grass-type water ecology steady expansion system also comprises a step of introducing native submerged plants in a sub-clear transparent area formed after lake returning clear water is mixed with lake water, the plant community is easy to survive and proliferate, and the steady expansion of the grass-type clear water range is guaranteed.

The matched auxiliary system provides a feasible and efficient algae slurry treatment method and a water hyacinth and other clearing and treating methods for harvesting aquatic plants in the normal production process and the daily maintenance and management of water ecology, namely a solution for utilizing biomass waste is provided, and the problem of secondary pollution of biomass is solved.

The most direct objects of the utility model are: through the powerful bypass purification engineering technical means of function, the lake pollutants are removed forcibly and continuously, the whole flow of the lake is realized, clear and oxygen-enriched clean water is continuously obtained from the interior of the lake to construct a large circulation of a lake water body, meanwhile, the grass type water ecology taking the native submerged plants as the main body is effectively reconstructed, the past pool of dead water and the lake black water and odorous water 'green paint' water are completely distinguished, and the beautiful scene that 'clear bottom water grass drags the fish to fly to the shallow bottom' is practically reproduced.

The utility model has the following five advantages and simultaneously has 5 objects:

1. forcibly removing the pollutants with high influence factors in the lake, continuously reducing the total amount of the pollutants, and having high decontamination efficiency;

2. a prerequisite condition is created for successful establishment of water ecology, and survival and proliferation of the introduced native submerged plants are ensured;

3. the adopted technology is mature and reliable, the construction cost and the operation cost are controllable, and the large-scale application is free from worries;

4. the artificial forced purification and the ecological natural purification are perfectly cooperated, and the self-regulation and anti-pollution buffering capacity is realized;

5. the method has the advantages of green, low carbon, energy conservation and emission reduction, high water body circulation energy efficiency, good interaction mass transfer effect and unlimited running water supply.

The utility model realizes the purpose by utilizing the following five innovative technical means and simple processes:

1. the initiated high-influence factor pollutant bypass purification circulation technology is utilized.

The technology is a shore-based circulation purification technology based on a bypass physicochemical method principle and an artificial kidney principle, and is a powerful engineering technical means of extracting lake water, adding medicine, coagulating sedimentation, removing algae by air flotation, filtering a homogeneous filter material in a deep bed and the like, directly and forcibly removing lake high-influence factor pollutants TP (total phosphorus) and the like, continuously reducing the total amount of the pollutants, and providing a 'running water' source support for the regeneration of grass-type lakes.

The background pollutants of lakes are hundreds of thousands of types, but can be divided into three types, namely organic pollutants (represented by Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD)), nitrogen (N) and phosphorus (P) pollutants and secondary pollution algae pollutants. According to the years of investigation of more than 50 lakes in the middle and lower reaches of Yangtze river by the institute of aquatic organisms of Chinese academy of sciences and the years of monitoring of the security lake of Dazhu province in Hubei province since 1987, the research finds that: when the concentration of TP in the lake water exceeds 0.08-0.12 mg/L, the ecological system is converted from a grass type stable state to an algae type stable state; if the algae type steady state is converted into the grass type steady state, TP needs to be lower than 0.04-0.06 mg/L. Therefore, the full-system phosphorus control is very important, and TP of the factory tail water of municipal sewage treatment plants discharging tail water to lakes, the application of agricultural non-point source phosphate fertilizer and TP of lake water bodies (containing bottom mud) need to be removed by TP reduction as much as possible.

The utility model firstly utilizes bypass 'artificial kidney dialysis' water treatment facilities in China, and through high-efficiency shore-based purification means such as dosing coagulation sedimentation, air flotation, deep bed filtration and the like, the TP concentration of clear water returning from a factory to a lake is firmly controlled to be less than or equal to 0.04mg/L or even lower value manually and forcibly, and then the clear water is conveyed to a distant lake bank through a pipeline and then returns to the lake (so as to avoid short flow), thereby continuously removing the high-influence factor pollutants TP and the like in the lake; except TP, this process can also get rid of algae pollutant, COD and muddy colloidal pollutant brute force in step, also has partial removal effect to nitrogen (ammonia nitrogen and total nitrogen), especially through adding the two-stage process of medicine coagulating sedimentation air supporting (first order) and deep bed filtration (second level), gets rid of algae, SS (suspended solids) and colloidal pollutant very thoroughly, and is the highest to TP, algae, COD's removal efficiency, and is secondary to the removal efficiency of nitrogen. Finally, the turbidity of the effluent is less than or equal to 1NTU, the transparency is more than 12m, and DO is more than or equal to 4-5 mg/L, which almost reaches the same level as the water quality of urban tap water, so that the removal of various pollutants is guaranteed.

2. The initiated technology for artificially and forcibly increasing the transparency of lake water to promote the photosynthesis under water is utilized.

The technology is based on a physicochemical purification principle and a principle that submerged plants depend on photosynthesis to the greatest extent, high-quality clear water with turbidity less than or equal to 1NTU and transparency more than 12m is obtained through the two-stage process, then the native submerged plants and the like are introduced into a sub-clear transparent area formed after lake water is mixed, a prerequisite condition is created for successful establishment of water ecology, and the introduced native submerged plants are guaranteed to obtain advantages to survive and proliferate. Just so-called: asking the canal which is clear as allowed is the way of running water from the source head.

Experience shows that in the past, the local submerged plants are planted in the fast growing period of the submerged plants blindly, although control measures (which may not be very effective and thorough) of TP entering a lake are actively adopted and supporting measures such as reducing the water level to increase illumination are also adopted, the effect is always poor or can not be sustained, and the reason is not obvious: firstly, the illumination transparency of the submerged plant planting area is insufficient or cannot be guaranteed, and the method for reducing the water level and increasing the illumination is a relatively passive measure compared with the method for actively making the water clear; secondly, nutrients are brought by the fact that the dead water pool does not flow and can not continuously carry out mass transfer exchange; thirdly, the concentration of TP in the planting area does not reach the threshold range requirement (probably about 0.1mg/L or even higher) of less than or equal to 0.04-0.06 mg/L, so that the algae in the planting area can be bred into pioneer organisms very easily, the light transparency of the water body is seriously reduced, and the introduced submerged plants are difficult to survive and breed and can not be recovered to the grass-type water ecology smoothly.

The utility model is just the initiated technology for supporting the plants by artificially and forcibly increasing the transparency of lake water to promote the photosynthesis under water, so that the self-produced oxygen-enriched clear water is continuously returned to the lake and is mixed with the lake water to form a sub-clear transparent area, the sufficient illumination is ensured, and the flowing live water continuously brings N, P and other nutrients, so that the introduced native submerged plants are easy to survive and thrive, and finally, the healthy and stable water ecology with abundant submerged vegetation is formed.

3. The purification and regeneration technology of the algae polluted water source by a physicochemical method is utilized as the original boundary-crossing key technology.

The utility model develops a new method, creatively adopts a boundary-crossing key technology, namely an algae polluted water source physicochemical purification and regeneration technology applied to the field of urban water supply (tap water), and is a technology which firstly crosses the boundary from the technical field of water treatment (tap water) engineering to the technical field of water circulating water ecological reconstruction.

As the water treatment (tap water) field is classified into the municipal water supply and drainage engineering technology, and the water circulating water ecological restoration field is classified into the environmental science and environmental ecology, the lake regeneration system belongs to the cross-boundary transverse combination technology, and the high efficiency and the stable reliability of the lake regeneration system are still kept as before in the cross-boundary field of water ecological reconstruction.

The key technology introduced by the bypass purification measure in the utility model is mature technologies such as chemical-adding coagulating sedimentation, pressurized dissolved air floatation, deep bed filtration and the like based on a physicochemical method, wherein the chemical-adding coagulating sedimentation technology has a history of hundreds of years and is widely applied to the global urban tap water production; the pressurized Dissolved Air Flotation (DAF) technology is widely applied at home and abroad, has more than 90 years of history (starting from a certain paper mill in Sweden 1930), has an effect on removing algae, is suitable for treating water with high chroma, high organic matter content, low oil content, low surface active substance content or rich algae, synchronously removes COD, SS and colloid while removing algae and phosphorus in a large scale and efficiently, and has high DO of effluent; a deep-bed filtering technology for a homogeneous filter material air-water backwashing sand filter tank has more than 30 years of history in China (the technology of French Delikai company is introduced to be put into production in Nanjing in 1990, 7 months), and is almost adopted in large-scale high-quality water works at present, a small amount of residual pollutants in water after coagulating sedimentation and air floatation treatment are further and thoroughly removed, the transparency of the water body is improved to be more than 12m after filtering from about 0.8-1.2 m before filtering, and the turbidity is reduced to be less than or equal to 1NTU from 3-5 NTU.

In view of this, the grass-type lake regeneration system of the utility model can completely realize the aim of bypass water purification: the filtered water hardly contains any pollutants and turbid matters such as algae, SS and the like, the quality of the outlet water is basically consistent with that of urban tap water, the turbidity standard is the same as the national standard of the urban tap water (less than or equal to 1NTU), the transparency of the lake returning clear water is more than 12m, and the DO is more than or equal to 4-5 mg/L.

In addition, the process flow of the grass-type lake regeneration system is simpler than the production flow of urban tap water, and the reasons are that a sand setting procedure (sand setting is needed in the river flood period), disinfection (different purposes), a large-scale regulating tank (no consideration of change of hours) and the like are not needed, so that the lake regeneration system is simple and convenient to operate, long in time and stable, reliable in technology, easy to implement, standardized in operation, environment-friendly, capable of being applied in a large scale, free of any worries about the rear in the aspects of stability and reliability, and controllable in construction cost and operation cost with reference to the urban tap water.

By reflecting other lake bypass purification technologies, the technical system is far from being mature without urban tap water, the removal of high-influence factors or characteristic pollutants is far from being efficient without the method, and the other technologies have the problems in the application process, which can influence the water ecological reconstruction effect and even determine whether the details are successful.

4. An innovative coupling technology of bypass artificial purification/forced large circulation in cooperation with dynamic reconstruction of water ecology is utilized.

The grass-type lake regeneration system meets the initial requirements of the system by increasing the water treatment capacity of the bypass purification project, and the total capacity of the system is properly surplus in the middle period, so that the system can actively obtain the self-regulation and anti-pollution buffer capacity. The advantages of the coupling technique are represented by: the removal amount of the bypass purification pollutants and the removal amount of the water ecological self-purification pollutants are in dynamic balance in an initial recovery stage (which may be 2-5 years or even longer and is different according to the size of the lake, the pollution degree, the water body replacement and the size of the engineering scale), a stable operation stage and a long-term development stage of water ecological reconstruction. Moreover, the coupling technology water ecosystem can gradually exert the productivity to the maximum so as to save the power and the medicament cost of manual forced purification.

The rough dynamic coordination capability is calculated as follows:

assuming that the removal amount of the artificial forced bypass purification pollutants is 140 in dimensionless value initially, and is adjusted to 50 year by year according to actual needs, in the process of successfully reproducing the grass-type clear water lake, the removal amount of the water ecological self-purification pollutants is gradually regenerated and recovered to 100 from initial 10, and the total removal amount of the pollutants 150 (initial 140+10 is equal to the stationary period 50+100) coordinated with two phases is always in a state of equilibrium with 150 of the total amount of the pollutants (containing the slow release amount of bottom mud) entering the lake, so that the regeneration effect of the grass-type lake is clearly seen from the first day of dynamic trial production.

When the lake is successfully repaired to reach the self-cleaning capacity of 100, the total pollutant removal capacity (140+100 to 240) of the system is larger than the total pollutant amount (containing the substrate sludge slow-release amount and the total amount is 150) entering the lake at the moment, so that the system has the self-regulation and anti-pollution buffering capacity of 90, and the regulation and buffering capacity is about 60 percent of the total initial pollutant amount of 150. Therefore, the spare capacity of the system can lay a good foundation for the future larger development of the lake basin, which is also an advantage that any other regeneration method cannot obtain.

5. The following simple process is ingeniously utilized, and the green, low-carbon, energy-saving and emission-reducing effects and the high efficiency of each function are realized.

The utility model uses weir crest free flow cascade drop water required by normal production to oxygenate, uses water pump power to lift the water to a purification facility for purification, and then conveys the water to an upstream lakeshore by a pipeline to forcibly form large circulation inside and outside the lake body, and uses various simple, convenient and effective forms such as environment-friendly disposal idea of centralized carbonization of lake biomass waste, so that the system can obtain maximum ecological total benefit with lowest energy consumption and drug consumption, thereby being a true green low-carbon, energy-saving and emission-reducing lake regeneration system, and the specific reason is as follows:

the lake water oxygenation of the utility model is realized by the following steps:

in the production process, water flows pass through a water taking weir of a water taking port on the surface layer of a lake, a water distribution weir of a high-level grid water distribution pool in a lake bank water source plant, a finger-shaped water collecting tank, a water inlet and outlet water distribution weir of a homogeneous filter material air-water backwashing sand filter, and the like to drop and oxygenate for multiple times, and a pressurized dissolved air micro bubble air flotation process of a coagulating sedimentation (clarification) air flotation algae removal pool is sequentially oxygenated, and finally secondary oxygenation of a waterfall water scene entering the lake is carried out. Therefore, the water body oxygenation method of the lake regeneration system belongs to an environment-friendly sustainable method with high efficiency, low consumption, greenness, low carbon, energy conservation and emission reduction. The effectiveness of the method can be easily proved by detecting the DO value of the dissolved oxygen of the factory water of the surface water source city tap water plant.

Compared with the lake water oxygenation method in the prior art, such as the aerator oxygen supply machine in the prior art 1, the technology 3, the technology 6 and the like, the aeration oxygen supply machine or the oxygenation aeration blower is not arranged, the power device special for aerating and oxygenating the water is not adopted, all levels of weir crest drop in the process are fully utilized for natural oxygenation, and the satisfactory water oxygenation effect can be obtained by only paying attention to ventilation (not sealing) at the water drop and considering that the weir crest drop is in a free flow rather than a submerged flow state (judged by critical water depth parameters) as far as possible by carefully observing the experienced and uncomplicated engineering technical measures and details.

The integral flow making of the utility model is realized by the following steps:

the utility model makes the flow of the lake water body integrally, not by the impeller mode of other methods (local violent, short flow at a slightly far position, high energy consumption, incapability of really rectifying flow, serious energy waste and high operation cost), nor by forming local up-down circulating flow through deep aeration (even if more deep aeration is arranged, the lake integral horizontal flow cannot be formed), like the prior art 1, the prior art 3, the prior art 6, the prior art 7 and the like, but by a large-circulation low-energy consumption forced mode of water pump lifting, namely, taking water from multiple points at the downstream or downwind direction of the lake, purifying the water by a bypass, conveying the water to the upstream or upwind direction of the lake by a pipeline, forming multiple basically parallel streamline large circulation from the whole layer of the lake, therefore, the whole flow making efficiency of the lake is high, the unit energy consumption of the water body flowing slowly is low, the mass transfer effect between pollutants in the lake and submerged plants is good, the circulating water has high energy efficiency, so the utility model is embodied again in green and low carbon. Through the simple engineering technical measure, the whole lake can be kept in the flow of clear running water for a long time, a pool of dead water and a lake black water and odorous water green paint water are forever distinguished, and the water environment of the lake enters the expected virtuous cycle.

The utility model discloses a grass-type lake regeneration system, which also provides a solution for utilizing biomass waste for algae slurry treatment, water hyacinth (water hyacinth) and other harvested aquatic plants in the normal production process and the daily maintenance and management of water ecology, and specifically comprises the following steps: the method comprises the steps of pumping algae slurry skimmed by an air floatation algae scraping machine into a biomass carbonization workshop by a slurry pump, draining and extruding plant residues such as water hyacinth and the like automatically fished by a grid cleaner, water hyacinth fished ashore from a lake and harvested aquatic plants together in the biomass carbonization workshop, crushing the water hyacinth and the like, deeply dehydrating and finally carbonizing the biomass, firing the biomass at a high temperature in an anoxic state by adopting a high-pressure pressing mechanical charcoal process without using a bonding agent to produce environment-friendly mechanical charcoal (a nationally recognized green and environment-friendly product) for daily warming, barbecue, charcoal chafing dish and the like, solving the problem of final disposal and utilization of a large amount of biomass in daily life which must be considered in a lake regeneration system, eliminating the secondary pollution problem of the biomass, and relieving worries of the prior art.

The grass-type lake regeneration system also provides a feasible scheme for the circular economy and sustainable development of the productivity of the water ecosystem, focuses on cultivating the water economic crops and stocking high-quality wild fishes and the like while purifying the water quality in the water ecology to construct a complete ecological food chain and rich biodiversity, fully exerts the economic benefits, the environmental benefits and the social benefits of the lake economic crops, the lake wild fishes (non-feed feeding properties) and lake travel, is just like the famous full scene of checking the lake and catching in the dry lake in the Songyuan city of Jilin province, and injects strong vitality into the sustainable development of lakes.

In conclusion, the grass-type lake regeneration system has remarkable sustainable development value and socialist ecological civilization value of high efficiency, low consumption, greenness, low carbon, energy conservation and emission reduction.

The utility model realizes the purpose of the utility model more satisfactorily through the technical creativity, advancement and practicability of the five aspects and the cooperation of various guarantee means, and the working process and the principle are not complicated and wonderful, even are very concise and clear.

The working process and the principle of the grass type lake regeneration system are as follows:

arranging water taking wells with approximately equal intervals on a cross section vertical to the overall flow direction of the lake in the downstream or main wind downwind direction of the lake, wherein the number of the water taking wells is not less than 2; the top of the water intake well is provided with surface water intake ports, and the number of the surface water intake ports is not less than 2; the lower part of a water intake well which is partially positioned in deep water and is close to the lake bed is provided with lower-layer water intake ports, and the number of the lower-layer water intake ports is not less than 1; all water taking wells are connected through water diversion pipelines at the bottom of the lake in sequence and finally connected with water taking pump house inlets located on the sides of the lake shore; the outlet of the water taking pump room is connected with a high-level grid distribution pool on the bank through a water taking valve flowmeter and a water taking pressure pipeline. The system comprises a water intake pipeline, a water intake pump room and the like from a water intake of a water intake well to a water intake pressure pipeline, and forms a multipoint water intake system (I) for the algae-containing turbid water in the lake.

The high-level grid distribution tank is sequentially connected with a coagulating sedimentation (clarification) air flotation algae removal tank, a homogeneous filter material air-water backwashing sand filter tank and a backwashing pump room through connecting pipelines to form a bypass physicochemical treatment purification system II. And the back-flushing pump room at the rear end is connected with the buffering water absorption well of the next system through a connecting pipeline.

The buffering water absorption well is connected with a clear water pressurizing pump room through a pipeline, then passes through a clear water valve flowmeter, a combining well and the like, and then passes through a clear water conveying pipeline with a long distance to convey clear water to a clear water returning and lake replenishing point at the upstream direction of the lake or a main wind upward direction to the lake bank, the number of the lake returning and lake replenishing points is not less than 5, and the replenishing point is set into various forms of lake entering and water falling waterfall scenes to continuously oxygenate the lake returning and clear water. A waterfall waterscape from a buffer water suction well to a lake entering waterfall comprises a clear water pressurizing pump room, a clear water conveying pipeline and the like, and a clear water pipeline conveying multi-point lake returning system III is formed. At the moment, water is taken from the upstream of the multipoint lake returning system and the downstream of the multipoint water taking system, so that the forced uniform flow of the lake is skillfully formed, the lake is continuously circulated, and the expected vision that artificial self-circulation of the lake is 'active running water' is realized.

The lake-entering water-fall waterfall waterscape and the grass-type water ecology steady-step expansion system form a whole.

The grass type aquatic ecology steady-step expansion system IV mainly comprises aquatic organisms and corresponding management measures, and comprises the steps of introducing native submerged plants in a clear water area, planting emergent plants at shallow water and shoreside, constructing an ecological floating island at a lake bay, constructing other suitable floating-leaf plants, putting proper amount of native fish fries, other suitable aquatic animals, insects and the like, and finally matching with corresponding seedlings, harvesting, salvaging, catching and other measures.

The auxiliary systems matched with the four systems at least comprise a power transformation and distribution room, a dosing room, a wastewater treatment and recovery system, a biomass carbonization workshop, a sludge deep dehydration/drying workshop, a laboratory/central control room and other facility measures. The 6 main hardware facilities of the auxiliary system are as follows (not limited):

1. a power transformation and distribution room: the power is provided for the self electric equipment of the water taking system, the purifying system, the lake returning system and the auxiliary system;

2. a dosing room: provides a prepared coagulant liquid medicine such as FeCl for a coagulating sedimentation (clarification) air floatation algae removal tank₃PAC, and the like, and also supplies pressurized dissolved air for the air floatation algae removal tank;

3. waste water treatment and recovery system: the system is used for treating sludge discharge water of a coagulating sedimentation (clarification) air flotation algae removal tank and squeezed residual liquid of a sludge deep dehydration workshop, and recycling backwashing drainage water of a homogeneous filter material air-water backwashing sand filter after sedimentation treatment;

4. and (3) biomass carbonization workshop: the device is used for treating biomass residues such as algae slurry separated in an air floatation procedure, water hyacinth (water hyacinth) intercepted by a grid distribution pool, and decayed aquatic plants and the like fished/harvested in lakes, the organic biomass is crushed after being drained and extruded, and is fired at high temperature under the anoxic condition by adopting a high-pressure pressing machine-made charcoal process without using an adhesive to produce environment-friendly machine-made charcoal (a nationally recognized environment-friendly product) which can be used for living heating, barbecue, charcoal chafing dish and the like, so that the problems of final treatment and utilization of a great amount of daily biomass in lakes are fundamentally solved, the secondary pollution problem of the biomass is eliminated, and the worries of the prior art are relieved;

5. sludge deep dehydration/drying workshop: used for deeply dewatering/drying the mud separated from the wastewater treatment system, and the dried mud cake contains a small amount of coagulant such as FeCl added in the production process except for a small amount of substances₃Most of the actual, besides PAC, are the contaminants that have been converted to solid form, including organic contaminants (COD, etc.), nitrogen (N) phosphorus (P) contaminants, colloidal contaminants, SS, etc., which are forcibly removed from lakes;

6. laboratory/central control room and other facility measures, including soft measures (software, management methods), etc., provide guarantees for normal production and experience accumulation for continued development.

The above working process is seemingly complicated, and the practical rule can be summarized into 3 closely related processes: 1, a forced whole-lake water circulation process which is jointly created by a water taking system and a lake returning system; 2, a manual forced purification process for treating water quality by a physical and chemical method of a bypass purification system; and 3, the water ecology steady reconstruction of the water ecology expansion system, namely the natural water quality purification process.

The working principle of the above 3 working processes is briefly described as follows:

1. the working principle of the whole lake running water circulation is as follows: after the lake water is lifted to a proper height position on the lake bank by utilizing the power of a water pump to be purified into clear water, the clear water is remotely conveyed to the upstream or upwind position of the lake to return to the lake by utilizing the hydraulic principle that the water flows to the lower position, the clear water is remotely conveyed to the upstream or upwind position of the lake by a pipeline under the action of potential energy, the hydraulic flow state of the lake is forced to be changed, the continuous working process that the downstream or downwind position of the lake continuously pumps water → the upstream or upwind position continuously returns to the lake by clear water is formed, the water quantity and the water level of the lake are not changed in the process, the uniform and slow flow of the running water is subjected to large circulation inside and outside the lake body, the appearances of the previous pool of dead water and the lake black water, the odor water and green paint water in the lake are thoroughly changed, and the water environment and the water state of the lake enter the expected virtuous circulation.

The water source plant arranged at the appropriate height position of the lake bank needs to comprehensively select a plant site and a plant site elevation according to the actual hydraulic lifting total lift and the topographic elevation condition of the water source plant purification treatment facility, the plant site and the plant site elevation can be lifted by a water taking pump once and then gravity flow, or lifted by pressurizing twice after water taking, and the determining factor is the topographic elevation of the purification treatment facility, which cannot be summarized.

2. The working principle of manual forced purification is as follows: by utilizing the bypass purification principle of physicochemical treatment such as dosing coagulation sedimentation, coagulation air flotation algae removal, chemical phosphorus removal, quartz sand deep bed filtration and the like, and adopting a secondary treatment forcing means, the algae-containing turbid water is subjected to high-efficiency algae removal, TP reduction, COD, SS, turbidity and colloid pollutants, and partial ammonia nitrogen and TN (total nitrogen) pollutants are removed, and the pollutants are finally discharged out of the system in solid forms such as mud cakes, biomass machine-made charcoal and the like, so that the aim of continuously and forcibly reducing the lake pollutants is fulfilled; meanwhile, by means of the essential water flow cascade drop in the production process (the main purpose is to uniformly distribute water and uniformly discharge water and ensure the designed water level in a water treatment structure), natural oxygenation, pressurized dissolved air floatation algae removal along with oxygenation, oxygen charging and the like for lake entering drop waterfall for creating a waterscape, the final lake returning clear water is obtained to reach excellent water quality indexes of COD (chemical oxygen demand) less than or equal to 20mg/L, TP and less than or equal to 0.04mg/L, turbidity less than or equal to 1NTU (total suspended solids), transparency more than or equal to 12m and DO (dissolved oxygen) more than or equal to 5mg/L, and the expected waterscape of 'coming from active head running water' is ensured to be realized.

3. The working principle of water ecological natural purification is as follows: the lake water quality depends on healthy and good water ecology to carry out natural purification, the self-purification capacity of a stable grass-type clear water lake ecological system is stronger, green plants and microorganisms in the water ecological system play an important role, biological groups such as plankton, benthonic animals and aquatic plants in the lake reduce the quantity and reduce the concentration of organic pollutants and nitrogen and phosphorus pollutants in the water body through metabolic activity (dissimilation action and assimilation action), so that the pollutants are converted, fixed, decomposed and degraded, and then the microorganisms, insects, mussels, fishes and the like are matched to construct an ecological food chain and biological diversity, thereby finally realizing the harmonious and beautiful scene of 'luxuriant aquatic plants and shallow fish flying'.

With the gradual recovery of the grass-type water ecology, the purification capacity of the water ecological system for water pollutants is stronger and stronger, the contribution of the water ecology in the whole system is larger and larger, the task burden and the operation cost of bypass purification treatment are directly reduced, but the successful construction of the water ecology is very dependent on the bypass purification treatment to provide preconditions (ensuring that the concentration of TP in the water body is low, clear and needs to slowly flow), and the water ecological system mainly provides a biological competitive advantage environment for submerged plants, namely, the threshold concentration and sufficient transparency of TP less than or equal to 0.04mg/L are used for obtaining sunlight, and the continuous N, P nutrient supply brought by the flowing water body enables harmful blue-green algae in the water body to be in a competitive disadvantage. Therefore, the onshore artificial purification and the underwater natural purification supplement each other, are indispensable and mutually cooperated and promoted, and make a contribution to the good and healthy water ecology together.

Compared with other lake regeneration systems, the utility model has incomparable superiority in the following 3 aspects:

1. in terms of forced and sustained pollutant abatement: the utility model changes the passive mode into the active mode, adopts the high-efficiency purification technology of the bypass physical and chemical method, can remove the pollutants manually and forcibly, can continuously and controllably reduce the total amount of the pollutants and ensure the total amount of the pollutants, ensures that the water quality of the circulating water replenishing in the system is clear and transparent and is rich in dissolved oxygen, and creates a prerequisite condition for the successful establishment of the grass-type water ecology;

2. in the aspects of lake flow making and water body large circulation: the utility model has unique and reliable flow making mode, low circulating energy consumption, good circulating effect and good interaction mass transfer effect, is completely different from the flow making of the traditional underwater propeller or various forms of aeration machines, ensures that the source of the internal water is continuous, and has higher circulating energy efficiency;

3. in the aspects of water ecology establishment and water ecology natural purification: the local submerged plants obtain competitive advantages due to three key factors of TP, transparency and flowing nutrients, the grass type water ecology can be revived strongly, the natural purification of the water ecology is complementary with the manual forced purification of a bypass, the two phases are cooperated, the total purification capacity of the whole system is strong, the obvious pollution resistance buffering capacity is realized, and the bright ecological development prospect is realized.

The technical originality, the technical reliability and the obvious technical advantages of the utility model are reflected in the following three aspects:

one is the technical originality is realized in the following 4 dimensions:

1 is the originality of the targeted and cyclic removal technique of high-impact factor pollutants

The technology creatively solves the problems of cost and efficiency of reducing the relatively low concentration (0.1-0.2 mg/L) of TP of the polluted lake water to be lower (TP is less than or equal to 0.04 mg/L).

It is known that the TP in the highest standard primary A standard of the national standard of pollutant discharge Standard of municipal wastewater treatment plant (GB 18918-2002) is less than or equal to 0.5mg/L, while the biochemical treatment technologies of the biofilters such as the prior art 2, the prior art 3, the prior art 8 and the like or other technologies can easily solve the problem if the concentration of the TP in the lake water reaches the TP of less than or equal to 0.04mg/L from the magnitude of 0.1-0.2 mg/L through the biochemical treatment technology, which is difficult or unreasonable.

2 is the originality of the supporting and planting technology for artificially and forcibly increasing the transparency of lake water to promote the photosynthesis under water

The technology creatively solves the problem that submerged plants planted in other prior art are often difficult to survive.

The method is based on two stages of processes of physical and chemical purification (coagulating sedimentation air flotation and deep bed filtration), ensures that the illumination of the lake returning clear water area is fully guaranteed, flowing live water continuously brings N, P and other nutrients, and the algae in the low TP area are in the competitive disadvantage and cannot rob illumination resources, so that the introduced native submerged plants are easy to survive and thrive, and finally, the healthy and stable water ecology with abundant submerged vegetation is formed.

3 is the original application of the key technology of the physicochemical method purification regeneration technology of the algae polluted water source

The method is applied to the technical field of ecological reconstruction of water circulating water through innovation, and solves the problems of feasibility and reliability of high flow, low concentration, low cost and high quality of lake water.

The key technology can easily ensure that the transparency of a running water system before entering a lake is more than or equal to 12m, the turbidity is less than or equal to 1NTU, the dissolved oxygen DO is more than or equal to 5mg/L, the quality of the running water system is basically consistent with that of urban tap water, the turbidity standard is the same as the national standard (less than or equal to 1NTU) of the urban tap water, and except that purified water is not drunk in life and prepared, the ecological water replenishing for the self-circulation of the lake has more than sufficient time, and the ecological water replenishing is more reliable in the aspects of water quality and water quantity compared with other ecological water replenishing modes because the water quality is excellent and the self-circulation supply is unlimited.

4 is the originality of the manual forced purification/forced large circulation coupling water ecological dynamic reconstruction technology

By utilizing the coupling technology, not only is harmonious and elegant water environment water ecology obtained, but also the task burden and the operation cost of the bypass purification system are directly reduced, and the self-regulation and anti-pollution buffering capacity is also achieved, thereby achieving three purposes at one stroke.

Secondly, the technical reliability is realized in the following 3 points:

1, the principles of the adopted physical and chemical method, the artificial kidney, the hydraulics principle of water body flow making, the system technical parameters and the like are very reliable, and are repeatedly proved by water treatment engineering practices for many years, and national standards of China, such as outdoor water supply design standard, pump station design standard, algae-containing water supply treatment design standard and the like, have detailed technical regulations and meet the technical reliability;

2, the construction form of the water taking facility of the grass-type lake regeneration system, various types and internal equipment of the shore-based purification facility, the engineering technical contents of the upstream lake returning system and the like comprise various structures, pipelines, equipment, materials, instruments and the like, the design, construction, purchase, installation, operation and maintenance and the like of the system are mature and reliable, and the system reliability is undoubtedly realized only by controlling according to the national current quality standard;

3, in the application and implementation process of the utility model, the utility model has no obscure concept, no wonderful and ingenious details, only standard and clear specific engineering contents and mature and rich operation management regulations, the system structure is clear and clear, and the technical reliability is clearly and obviously revealed.

In a word, the multiple new technologies adopted by the utility model only need to control the civil engineering quality and the installation engineering quality, comply with the operating regulations, are stable and reliable in operation and can be used for a long time.

Thirdly, the obvious technical advantages are embodied in the following 3 points:

1 is expressed in terms of high efficiency and high applicability.

The bypass physicochemical purification technology based on the grass type lake regeneration system is far higher in total purification efficiency of the lake water polluted by algae than the prior art. The biochemical treatment technologies of the biofilters such as the prior art 2, the prior art 3, the prior art 8 and the like, or the simple low-efficiency physicochemical treatment technologies of the power equipment such as the oxygenator/the aeration blower and the like, which are specially used for oxygenating the water body (such as the prior art 1, the prior art 3, the prior art 6 and the like), the power equipment such as the bottom impeller/the deep aerator and the like, and circulating the water body flow (such as the prior art 1, the prior art 3, the prior art 6, the prior art 7 and the like) cannot complete the high-efficiency removal of the lake pollutants, and the technologies can be powerless or extremely weak in capacity for synchronously removing algae, removing turbidity, continuously reducing the water body pollutants, oxygenating and circulating, and ensuring the survival and proliferation of the introduced native submerged plants, and the like The method has the advantages of saving energy, generating circulation, strengthening mass transfer, ensuring survival and proliferation of introduced native submerged plants and the like, and therefore, the method has outstanding technical capability, high efficiency and wide applicability.

2, the method has the obvious technical advantages of self-integration, self-regeneration and no dependence on the outside.

The prior art for treating the lake pollution has a good effect, ecological diversion and water change are carried out from a remote external cross-drainage basin (such as the Dian pond is diluted by diversion from the cowstall river cross-drainage basin, the line length is 116km, the lift is 225m, the west lake is pumped from the Qiantanjiang river to change water, and the like) or a large amount of city tap water is used for supplementing water, however, high-quality clean surface water resources are certainly supplied to cities as drinking water sources preferentially, the amount of water resources left as ecological diversion and water change is very limited, the cost of supplementing water by using tap water in a large amount is very high, a small amount of water can be supplemented (but has a very little effect), a large amount of water cannot be accepted economically, and the comprehensive cost of the cross-drainage basin ecological diversion and water change is obviously higher than that of the lake regeneration system, so the lake and lake shore purification facility are self-integrated, self-regeneration and water supply is unlimited, the obvious technical advantages are that the lake and lake purification facility only need to be simply made by the outside, the hope of being held in place by changing water from external ecological water or supplementing a large amount of water by tap water is not needed. Therefore, the method is easy to implement because of not depending on the outside, and is easy to realize the self-control of the lake pollution.

3, the method has the obvious technical advantages of mature and reliable technology, energy conservation, low carbon, controllable cost of each item and good technical economy.

The purification technology based on the physicochemical method is mature, the adopted oxygenation mode and the internal and external major circulation mode of the lake are completely different from the prior art, the energy-saving effect is obvious, and the total flow is shorter than the well-known tap water production flow, so that the construction cost and the operation cost are controllable, are not secret and are relatively low, the system is particularly suitable for strengthening and radically treating the algae polluted lake, and the obvious technical advantages are fully embodied, and the system is simple and convenient to operate, stable for a long time, standardized to operate, environment-friendly, capable of continuously reducing water pollutants, easy to restore the water ecology, easy to cooperate with the on-shore forced purification and the underwater ecological purification, low in cost and acceptable.

Compared with the prior art, the utility model has the following five beneficial effects:

1. forcibly remove the pollutants with high influence factors in the lake, continuously reduce the total amount of the pollutants and have high decontamination efficiency.

The grass-type lake regeneration system has definite directivity, can remove high-influence factors or characteristic pollutants very accurately, particularly can remove TP, algae, COD, turbidity, SS, colloid pollutants and the like very efficiently, has strong pertinence to lake pollution and water ecological reconstruction, and is particularly suitable for the enhanced radical treatment of algae-polluted lakes.

2. Creates a prerequisite for successful establishment of water ecology and ensures the survival and proliferation of the introduced indigenous submerged plants.

Because the utility model adopts two-stage working procedures of dosing coagulation sedimentation air flotation (first stage) and deep bed filtration (second stage), algae, SS and colloid pollutants are completely removed, the turbidity of the effluent is less than or equal to 1NTU, the transparency is more than 12m, the DO is more than or equal to 4-5 mg/L, and the water quality almost reaches the same level as urban tap water, thereby creating a prerequisite for successful establishment of water ecology. The clear and transparent water quality is very beneficial to photosynthesis of submerged plants, and the flowing running water continuously brings N, P and other nutrients, so that the introduced native submerged plants are very easy to survive and thrive, and finally, healthy and stable water ecology with abundant submerged vegetation is formed.

3. The adopted technology is mature and reliable, the construction cost and the operation cost are controllable, and the scale application is free from worries.

The physicochemical method purification technology based on the utility model is homologous with the surface water purification technology of urban tap water, is particularly similar to the main technical content in the national standard 'algae-containing water supply treatment design specification', is different only in application scenes and application purposes, so that the technology is mature and reliable as the ecological water replenishing purification technology for lake self-circulation, and is controllable and free from secrecy in construction cost and operation cost because the total flow is shorter than the well-known tap water production flow, is free from worries about large-scale operation, is particularly suitable for radical treatment of algae-polluted lakes, and is more reliable in both water quality and water quantity compared with the ecological water replenishing of any other technology because the self-circulation flow is free from worry.

4. The artificial forced purification and the ecological natural purification are perfectly cooperated, and the device has self-regulation and anti-pollution buffering capacity.

In the initial recovery stage, the steady operation normal stage and the long-term development stage of water ecological reconstruction, the total pollutant removal amount of artificial forced purification and ecological natural purification and the total pollutant removal amount of lakes are in dynamic balance in three stages. The regeneration effect of the grass-type lake is clearly seen from the first day of dynamic trial production. Compared with the prior art, the lake regeneration system has surplus regulation and buffering capacity which is equivalent to 60% of the total amount of the initial pollutants of the lake, and the surplus capacity can lay a good foundation for the future larger development of the lake basin, which is an advantage that other technologies cannot reach at present.

5. The method has the advantages of green, low carbon, energy conservation and emission reduction, high water body circulation energy efficiency, good interaction mass transfer effect and unlimited running water supply.

Compared with the prior art, the utility model has the advantages that the oxygenation mode and the internal and external major circulation mode of the lake are completely different from the prior art, the oxygenation high efficiency and low consumption and the high energy efficiency of water body circulation are realized, and the beneficial effects of good interaction mass transfer effect and unlimited live water supply are also realized, so the utility model has the very obvious beneficial effects of greenness, low carbon, energy conservation and emission reduction, and fully shows the sustainable development value and the socialist ecological civilization value.

The advantages show that the method can forcibly and continuously reduce the pollutants in the lake and can supply the running water which is rich in oxygen, clean and has the transparency more than or equal to 12 m; the utility model not only has high water circulation energy efficiency, good interaction mass transfer effect, unlimited living water supply and oxygen-enriched clear water quality, but also creates a prerequisite for water ecological restoration and provides powerful technical support for the intensified radical treatment of algae polluted lakes. Therefore, the utility model has wide application prospect.

Drawings

FIG. 1 is a schematic overview of the system flow;

FIG. 2 is a schematic plan view of a system flow;

FIG. 3 is a system flow detail diagram;

FIG. 4 is a schematic cross-sectional view of a bypass purification process;

wherein: firstly, a water taking system, secondly, a purifying system, thirdly, a lake returning system, fourthly, an expanding system and fifthly, an auxiliary system; 11-surface layer water intake, 12-lower layer water intake, 13-water intake well, 14-water conduit, 15-water intake pump room, 16-water intake valve flowmeter, 17-water intake pressure conduit; 20-a high-level grid water distribution tank, 21-a grid dirt removing machine, 22-a coagulant adding machine, 23-a coagulating sedimentation (clarification) air-flotation algae removal tank, 24-a sludge scraping and sucking machine, 25-a finger-shaped water collecting tank, 26-an air-flotation algae scraping machine, 27-a homogeneous filter material air-water back-flushing sand filter tank, 28-a back-flushing pump room and 29-a connecting pipeline; 31-buffer water suction well, 32-clear water pressure pump room, 33-clear water valve flowmeter, 34-combination well and exhaust valve, 35-clear water conveying pipeline, 36-clear water returning lake water replenishing point, and 37-water entering lake falling waterfall waterscape.

Detailed Description

The technical scheme of the utility model is further specifically described by the following embodiments and the accompanying drawings.

Example one

Referring to fig. 1, fig. 2, fig. 3 and fig. 4, the present invention will be further described in detail with reference to a small-medium lake in a certain city using a grass-type lake regeneration system of the present invention as an embodiment.

The area of the lake surface in the middle and downstream areas of the Yangtze river at the lake place is 6.38km²The length is about 3.23km, the width is about 2.6 kilometers, the average depth is 2.27m, the deepest depth is 5m, the shallowest depth is less than 1m, and the storage capacity is about 1429.4 kilometers³Annual precipitation of about 1500mm and natural alternation of water1 time/year, and 1800-2100 hours of annual sunshine hours. The lake is polluted by years of surrounding urbanization, after the sewage is intercepted around the lake and a sewage treatment plant is built, the pollution degree of the lake is obviously reduced, but the lake still belongs to IV-V class surface water according to the evaluation of national quality standard of surface water environment, is in a relatively stable state, and the annual average transparency of the water body is 0.437 m.

The grass-type lake regeneration system technology is adopted for treatment, and the treatment aim is to achieve the III-class water quality. The specific technical scheme is as follows:

water taking facilities with 4 points are arranged in the downstream direction of the lake to extract algae-containing turbid water, a water source plant is arranged on the lakeshore to serve as a purification facility, a physicochemical purification process is adopted, namely, a grid deslagging and water distribution process, a chemical adding coagulation precipitation process, an air flotation algae removal process, a turbid phosphorus removal process and a homogeneous filter material air-water backwashing sand filter deep bed filtration process are adopted, specifically, the process is shown in the figures 2 and 3, the treated oxygen-enriched clear water is conveyed to 7 points on the upstream lakeshore by pipelines, and is returned to the lake in the forms of 7 falling waterfall landscapes and the like to become the active water supplied by the lake self in a circulating manner, the returned lake clear water is gradually mixed with the lake water and slowly flows to the downstream, most (about 80%) of the returned clear water flows through the section of the downstream water taking opening to be extracted for the next round of purification cycle, and the returned clear water is repeatedly discharged for the next round of purification cycle; meanwhile, in a sub-clear transparent area formed by mixing lake water and lake water, the indigenous submerged plants are actively introduced and can be ensured to survive and flourish; along with the lasting of the running water circulation, the submerged plants gradually obtain advantages, the range of the grass-type clear water area is stably expanded, and clear and beautiful grass-type clear water lakes with fish flying shallow bottoms can be successfully reproduced.

The specific composition and main technical specification parameters of the present embodiment are as follows:

the design scale of the grass type lake regeneration system is 16 ten thousand meters³The scales of a lake algae-containing turbid water multi-point water taking system (I), a shore-based physicochemical treatment and purification system (II), a clear water pipeline conveying multi-point lake returning system (III), a grass-type water ecological steady expansion system (III), an auxiliary facility and an operation and maintenance management auxiliary system (III) are 16 ten thousand meters³/d。

The method specifically comprises the following steps: 4 surface layer water intake ports 11 of a water intake system (wherein 1 lower layer water intake port 12 is respectively arranged below 2 relatively deep water intake ports 11), 4 water intake wells 13 (supporting the water intake ports), a water conduit 14 (connecting the water intake wells in series) with the length of about 720m, a water intake pump room 15 with the inner diameter of 17m, a matched water intake valve flowmeter 16, a water intake pressure conduit 17 (conveying to a purification system) with the length of about 240m and the like, wherein the facilities are arranged in the direction of a water outlet at the downstream of a lake; the system also comprises a high-level grid water distribution tank 20 of the purification system II, wherein the tank comprises 2 grid dirt removers 21 and a coagulant adding port 22 arranged above the water distribution weir; a two-grid coagulating sedimentation (clarification) air-flotation algae removal tank 23, which comprises 2 sludge scraping and sucking machines 24, a plurality of finger-shaped water collecting tanks 25 and 2 air-flotation algae scraping machines 26; a homogeneous filtering material air-water backwashing sand filter 27 is matched with a backwashing pump room 28, a connecting pipeline 29 among water treatment structures and the like; the system also comprises a buffer water suction well 31 with two formats, a clear water pressurizing pump room 32, a matched clear water valve flowmeter 33, a combined well and an exhaust valve 34 and a clear water conveying pipeline 35 with the total length of about 7100m of the lake returning system III, wherein clear water is conveyed to a clear water returning lake water replenishing point 36 at the upstream direction 7 of the lake bank, and the water replenishing point is set into a lake falling waterfall waterscape 37 and the like; the method also comprises other measures such as introducing native submerged plants in the clear water area of the ecological expansion system, planting emergent plants at shallow water and shoreside, constructing ecological floating islands at the lake bay, putting other suitable floating-leaf plants, putting proper amount of native fry and other suitable aquatic animals and insects, harvesting, fishing and the like; finally, the system also comprises a power transformation and distribution room, a medicine adding room, a wastewater treatment and recovery system, a biomass carbonization room, a sludge deep dehydration/drying room, a laboratory/central control room and other facility measures of an auxiliary system (fifthly) built in the water source plant.

The lake water changing period of the embodiment is 90d, the water source plant arranged in the system is of an aboveground type, is positioned near the midstream direction bank in the downstream of the lake, and has a land area of about 30000m²(45 mu) is calculated, the elevation of the site terrain is about 2m higher than the lake surface, the installed capacity of the system is less than or equal to 640kW, and the lift H of the water pump_o12m, the lift H of the clean water pressure pump₁＝12m。

Detailed design parameters: the flocculation time t is 25min, the surface load V of a clear water area of an inclined tube sedimentation area is 8.5m/h, the surface load V of a filter pool is 10m/h, the turbidity of the effluent is controlled to be less than or equal to NTU, TP is controlled to be less than or equal to 0.04mg/L, and COD is controlled to be less than or equal to 20mg/L, DO and is controlled to be more than or equal to 5 mg/L.

The method can reduce 3520t (absolutely dry solid) of sludge entering the lake every year according to the annual average turbidity of the lake of 10NTU, and can reduce the sludge by 3.52 ten thousand meters per year if the water content of the lake sludge is 90 percent³。

The specific working process and detailed characteristics of this embodiment are as follows:

further, the well depth of the water taking well 13 is about 10m, and the inner diameter is 3.0 m; 4 water taking wells 13 are arranged in a straight line, are spaced by about 240m and are connected in series by a water conduit 14; the top of each of 4 water intake wells 13 is provided with 1 upturned bell-mouth-shaped surface water intake 11, which is convenient for acquiring algae-containing water on the surface layer and is beneficial to oxygenating water, wherein the cylinder wall of a shaft below 2 water intake 11 at relatively deep positions is provided with 1 lower layer water intake 12, which is convenient for acquiring bottom lake water with relatively high impurity content at the bottom layer; the specification of the water conduit 14 is DN 700-DN 1400 at the head end, the tail end of the water conduit 14 is connected with the water intake pump room 15, 4 water intake pumps (3 uses 1 device) are arranged in the water intake pump room 15, and the outlet of the water pump is connected with a matched water intake valve flowmeter 16 and a water intake pressure conduit 17 with the length of about 240m and a high-level grating water distribution pool 20. The specification of the water pressure pipeline 17 is DN 1400.

After the water taking, the algae-containing turbid water enters a water source plant for purification treatment according to the flow: the high-level grid distribution tank 20 is internally provided with 2 grid dirt removers 21 for intercepting and removing drifted-in garbage, aquatic plant residues and the like, and is provided with a water distribution weir for uniformly distributing flow to enter a coagulating sedimentation (clarification) air flotation algae removal tank 23, and the water distribution weir simultaneously plays a role in oxygenating water. In addition, in order to save energy consumption, and also in order to uniformly add the medicine to quickly diffuse and mix the medicine into the water body, and in order to add the triple purposes of the visual operation of the medicine, a coagulation medicine (FeCl) is arranged above the water distribution weir₃PAC, etc.) spraying and dosing pipe, namely coagulant dosing port 22 (the liquid medicine comes from the dosing room of the auxiliary system), spraying the liquid medicine into water flow and mixing rapidly by the subsequent water drop; thereafter, the water flows equally into each coagulating sedimentation (clarification) air flotation algae removal tank 23, in which the water flows firstA wastewater treatment and recovery system 53 for performing coagulation reaction and precipitation process to remove most of the pollutants, wherein the precipitated sludge is discharged from the 2 sludge scraping and sucking machines 24 to the auxiliary system; the water after coagulating sedimentation (clarification) is uniformly collected by a plurality of finger-shaped water collecting tanks 25, the water is dropped for further oxygenation in the collection process, then the water enters the rear part of the tank for air floatation algae removal treatment, the floating algae slurry is collected and scraped by 2 air floatation algae scraping machines 26 and is conveyed to a biomass carbonization workshop of an auxiliary system V for carbonization treatment; after the water flow is subjected to air floatation and algae removal, more than 90% of pollutants are treated (changed into silt and algae slurry), the transparency of the water body is increased from about 0.4m before entering a plant to about 0.8-1.2 m after air floatation and algae removal, the water body still is not clear enough and meets the bottom, and the water body needs to enter a homogeneous filter material air-water backwashing sand filter 27 for deep bed filtration treatment, and the principle is similar to underground water infiltration. The water quality after the filtration treatment is almost equal to the tap water without chlorination, at the moment, the water quality is clear and transparent, the pollutants are greatly removed, the removed pollutants are absorbed in the quartz sand layer of the deep bed filter material, and the backwashing water is discharged into the wastewater treatment and recovery system of the auxiliary system (V) for retreatment and recycling through the air-water backwashing of the matched backwashing pump room 28. The clear water after filtration completes the whole purification treatment process of the shore-based physicochemical method, and the clear water enters the structures of the lake returning system III in a gravity self-flowing mode through the connecting pipeline 29.

After the purification treatment, the clear water enters a buffer water suction well 31 which is connected with a water suction pipe of a clear water pressurizing pump room 32, the pump room is provided with 4 (3 is used and 1 is prepared) high-power clear water pressurizing pumps, the pressurized clear water enters a clear water conveying pipeline 35 with the total length of about 7100m after being metered by a matched clear water valve flowmeter 33 and exhausted by combining a well and an exhaust valve 34, and the clear water enters a 7 position (1) in the upstream direction of the lakeshore^#～7^#) The clear water returning and replenishing point 36 conveys clear water, and the starting end caliber DN1400 and the tail end caliber DN600 of the clear water conveying pipeline 35. The clear water flow parameters of the lake returning water replenishing points are as follows:

the detailed water quantity distribution calculation of the self-circulation supply running water of the lake: combining the specific shape of the lake, the current inflow and outflow position, the main wind direction, the surrounding environment of the lake and the likeFactor, hydrodynamic simulation was performed according to MIKE21 software model. The MIKE21 software model is developed by Danish institute of hydraulics, is mainly used for simulating lakes, gulfs, water flows, waves, silt and environmental fields, and is widely applied to the water environment remediation of lakes. In this example, after hydrodynamic simulation analysis is performed by using the MIKE21 software model, the lake returning water amount of the clear water lake returning point in this example 7 is determined, and the water source plant moves from near to far 1^#～7^#The flow of the point location is respectively: 1.2, 1.9, 2.6, 3.3, 2.8, 2.3, 1.9 ten thousand meters³A total of 16 km/d³/d。

When the water source plant completes and is filled with water, 1^#～7^#The clear water returns to a sub-clear transparent area which is gradually enlarged near a lake water replenishing point 36, the work of introducing native submerged plants and/or pollution-resistant favorite clear water plants is carried out, other work arrangements are also implemented one by one, the work comprises planting emergent aquatic plants at shallow water and on the bank, constructing ecological floating islands at lakes, also comprising native other suitable floating-leaf plants, and putting in proper amount of native fish fries at proper time, comprising other suitable aquatic animals, insects and the like, and preparing the work of harvesting, fishing and other measures for algae and aquatic plants; through the measures for constructing the biological diversity, submerged plants and the like thrive under the conditions of underwater photosynthesis and nitrogen and phosphorus nutrient nourishment carried by water flow, and the water ecosystem recovers stronger natural purification capacity by matching with other ecological measures, so that a clear and beautiful grass type clear water lake with shallow fish flying bottom is created.

Through simulation analysis, after 3 months of continuous development of the production of the bypass purification engineering and the water ecological reconstruction work, the water quality in the center of the lake and the upstream of the lake is obviously improved, and part of water quality indexes are superior to III class water standard values of surface water environmental quality standard and stably reach IV class water standard values and COD_CrThe reduction is 5.1mg/L, TP is reduced to be less than 0.04mg/L, and TN is less than 1.45 mg/L; with the gradual recovery of aquatic vegetation, TN is estimated to be less than 1.0mg/L after 2-3 years, because the removal of TN in lake water mainly depends on the assimilation removal of aquatic organisms, particularly aquatic plants. It is expected that the annual average lake water transparency will reach 0.54m, 0.65m after 2 years, 0.78m after 3 years after 1 year of project commissioning and continuous water ecology reconstruction,after 4 years, the thickness reaches more than 0.83 m.

The lake of the embodiment circularly supplies the running water per m³The direct cost of the power consumption (including lake water entering the factory for lifting and pressurized conveying), the medicine consumption, the labor cost, the maintenance cost and the like is 0.39 yuan (the daily expenditure is only 2246.4 ten thousand yuan per year, and the cost is calculated according to 5 days of shutdown and maintenance per year), and the construction investment, the occupied land, the operation cost and the like can be saved by about 50 percent compared with the cross-river basin ecological water replenishing or tap water replenishing of other systems, so the technical and economic benefits of the utility model are very obvious. The project adopts the grass-type lake regeneration system technology to obtain good lake pollution treatment and lake enhanced regeneration effect and technical and economic effect.

Example two

Referring to fig. 1, fig. 2, fig. 3 and fig. 4, the present invention will be further described in detail with reference to a large and medium lake in a certain city using a grass-type lake regeneration system of the present invention as an embodiment.

In the middle and upstream area of the Yangtze river in the lake region of the embodiment, the area of the lake surface is 30.75km²The length is about 7km, the width is about 5 kilometers, the average depth is 2.48m, the deepest is 6m, the shallowest is less than 1m, and the storage capacity is about 8150 kilometers³Basin rainfall runoff 5000.4 km³The water is naturally alternated for 0.614 times per year, and the annual sunshine hours are 1555-2106 hours. The lake is polluted by years of surrounding urbanization, after the lake is subjected to sewage interception and a sewage treatment plant is built, the pollution degree of the lake is obviously reduced, but the lake still belongs to IV-V class surface water according to the evaluation of the national quality standard of surface water environment, is in a relatively stable state, and the annual average transparency of the water body is 0.4 m.

The grass-type lake regeneration system technology is adopted for treatment, and the treatment aim is to achieve the III-class water quality. The specific technical scheme is as follows:

water taking facilities with 5 points are arranged in the downstream direction of the lake to extract algae-containing turbid water, a water source plant is arranged on the lakeshore to serve as a purification facility, a physicochemical purification process is adopted, namely, a grid deslagging and water distribution process, a drug adding coagulation precipitation process, an air flotation algae removal process, a turbid phosphorus removal process and a homogeneous filter material air-water backwashing sand filter deep bed filtration process are adopted, specifically, referring to fig. 2 and fig. 3, treated oxygen-enriched clear water is conveyed to 11 points on the upstream lakeshore by pipelines, and is returned to the lake in the forms of 11 falling waterfall landscapes and the like to become the active water supplied by the lake self in a circulating manner, the returned lake clear water is gradually mixed with the lake water and slowly flows to the downstream, most (about 66.7%) of the returned lake water is extracted to be used for the next round of purification cycle when the returned lake water flows through the section of the downstream water taking port, and the returned clear water is repeatedly discharged; meanwhile, in a sub-clear transparent area formed by mixing lake water and lake water, the indigenous submerged plants are actively introduced and can be ensured to survive and flourish; along with the lasting of the running water circulation, the submerged plants gradually obtain advantages, the range of the grass-type clear water area is stably expanded, and clear and beautiful grass-type clear water lakes with fish flying shallow bottoms can be successfully reproduced.

The specific composition and main technical specification parameters of the present embodiment are as follows:

the design scale of the grass type lake regeneration system is 45 ten thousand meters³The scales of a lake algae-containing turbid water multi-point water taking system (I), a shore-based physicochemical treatment and purification system (II), a clear water pipeline conveying multi-point lake returning system (III), a grass-type water ecological steady expansion system (III), an auxiliary facility and an operation and maintenance management auxiliary system (V) are 45 ten thousand meters³/d。

The method specifically comprises the following steps: the water taking system comprises 5 surface water taking ports 11 (wherein 1 lower layer water taking port 12 is respectively arranged below 2 relatively deep water taking ports 11), 5 water taking wells 13 (supporting the water taking ports), a water diversion pipeline 14 (connecting the water taking wells in series) with the length of about 2000m, a water taking pump room 15 with the inner diameter of 23m, a matched water taking valve flowmeter 16, a water taking pressure pipeline 17 (conveying to a purification system) with the length of about 680m and the like, wherein the facilities are arranged in the direction of a downstream water outlet of a lake; the system also comprises a high-level grid water distribution tank 20 of the purification system II, wherein the tank comprises 4 grid dirt removers 21 and a coagulant adding port 22 arranged above the water distribution weir; three coagulating sedimentation (clarification) air-flotation algae removal tanks 23 with two formats, which comprise 6 sludge scraping and sucking machines 24, a plurality of finger-shaped water collecting tanks 25 and 6 air-flotation algae scraping machines 26; the three homogeneous filter material air-water backwashing sand filter 27 is matched with a backwashing pump room 28, a connecting pipeline 29 among water treatment structures and the like; the system also comprises a two-format buffer water suction well 31, a clear water pressurizing pump room 32, a matched clear water valve flowmeter 33, a combined well and an exhaust valve 34 of a lake returning system III, and a clear water conveying pipeline 35 with the total length of about 17km, wherein clear water is conveyed to a clear water returning and lake replenishing point 36 at the upstream direction 11 of the lake bank, and the replenishing point is set into a lake falling waterfall waterscape 37 and the like; the method also comprises other measures such as introducing native submerged plants in the clear water area of the ecological expansion system, planting emergent plants at shallow water and shoreside, constructing ecological floating islands at the lake bay, putting other suitable floating-leaf plants, putting proper amount of native fry and other suitable aquatic animals and insects, harvesting, fishing and the like; finally, the system also comprises a power transformation and distribution room, a medicine adding room, a wastewater treatment and recovery system, a biomass carbonization room, a sludge deep dehydration/drying room, a laboratory/central control room and other facility measures of an auxiliary system (fifthly) built in the water source plant.

The lake water changing period of the embodiment is 180d, the water source plant arranged in the system is of an aboveground type, is positioned near the downstream of the lake and on the shore in the midstream direction, and the land area is about 52000m²(78 mu), the elevation of the site terrain is about 3m higher than the lake surface, the installed capacity of the system is less than or equal to 1800kW, and the lift H of the water pump_o15m, the lift H of the clean water pressure pump₁＝23m。

Detailed design parameters: the flocculation time t is 25min, the surface load V of a clear water area of an inclined tube sedimentation area is 8.5m/h, the surface load V of a filter pool is 10m/h, the turbidity of the effluent is controlled to be less than or equal to NTU, TP is controlled to be less than or equal to 0.04mg/L, and COD is controlled to be less than or equal to 20mg/L, DO and is controlled to be more than or equal to 5 mg/L.

9900t (absolute dry solid) of sludge entering the lake can be reduced in each year according to the annual average turbidity of the lake of 10NTU, and 9.9 ten thousand m of sludge can be reduced in each year if the moisture content of the lake sludge is 90 percent³。

The specific working process and detailed characteristics of this embodiment are as follows:

further, the well depth of the water taking well 13 is about 12m, and the inner diameter is 4.5 m; 5 water taking wells 13 are arranged in a straight line, are spaced by about 400m and are connected in series by a water conduit 14; the top of each of 5 water intake wells 13 is provided with 1 upturned bell-mouth-shaped surface water intake 11, so that the algae-laden water on the surface layer can be conveniently obtained, and the oxygenation of the water body is facilitated, wherein 1 lower layer water intake 12 is respectively arranged on the wall of a shaft cylinder below 2 relatively deep water intake 11, so that the bottom lake water with relatively high impurity content at the bottom layer can be conveniently obtained; the specification of the water conduit 14 is DN 1000-DN 2200 at the head end, the tail end of the water conduit 14 is connected with the water intake pump room 15, 4 water intake pumps (3 uses 1 device) are arranged in the water intake pump room 15, and the outlet of the water pump is connected with a matched water intake valve flowmeter 16 and a water intake pressure conduit 17 with the length of about 680m and a high-level grating water distribution pool 20. The water take-off pressure line 17 has the specification DN 2200.

After the water taking, the algae-containing turbid water enters a water source plant for purification treatment according to the flow: the high-level grid distribution tank 20 is internally provided with 4 grid dirt removers 21 for intercepting and removing drifted-in garbage, aquatic plant residues and the like, and is provided with a water distribution weir for uniformly distributing flow to enter a coagulating sedimentation (clarification) air flotation algae removal tank 23, and the water distribution weir simultaneously plays a role in oxygenating water. In addition, in order to save energy consumption, and also in order to uniformly add the medicine to quickly diffuse and mix the medicine into the water body, and in order to add the triple purposes of the visual operation of the medicine, a coagulation medicine (FeCl) is arranged above the water distribution weir₃PAC, etc.) spraying and dosing pipe, namely coagulant dosing port 22 (the liquid medicine comes from the dosing room of the auxiliary system), spraying the liquid medicine into water flow and mixing rapidly by the subsequent water drop; then, the water flow enters into each coagulating sedimentation (clarification) air flotation algae removal tank 23 in equal quantity, the coagulating reaction and sedimentation process are firstly carried out in the tank to remove most pollutants, and the settled sludge is discharged to a wastewater treatment and recovery system of an auxiliary system (V) by 6 sludge scraping and sucking machines 24; the water after coagulating sedimentation (clarification) is uniformly collected by a plurality of finger-shaped water collecting tanks 25, the water is dropped for further oxygenation in the collection process, then the water enters the rear part of the tank for air floatation algae removal treatment, the floating algae slurry is collected and scraped by 6 air floatation algae scraping machines 26 and is conveyed to a biomass carbonization workshop 54 of an auxiliary system; after the water flow is subjected to air floatation and algae removal, more than 90% of pollutants are treated (changed into silt and algae slurry), the transparency of the water body is increased from about 0.4m before entering a plant to about 0.8-1.2 m after air floatation and algae removal, the water body still is not clear enough and meets the bottom, and the water body needs to enter a homogeneous filter material air-water backwashing sand filter 27 for deep bed filtration treatment, and the principle is similar to underground water infiltration. Water quality after filtering treatmentAlmost equal to the tap water without chlorine for disinfection, at this time, the water quality is clear and transparent, the pollutants are greatly removed, the removed pollutants are absorbed in the quartz sand layer of the deep bed filter material, and the backwashing water is discharged into the wastewater treatment and recovery system of the auxiliary system (V) for retreatment and recycling through the air-water backwashing of the matched backwashing pump room 28. The clear water after filtration completes the whole purification treatment process of the shore-based physicochemical method, and the clear water enters the structures of the lake returning system III in a gravity self-flowing mode through the connecting pipeline 29.

After the purification treatment, the clean water enters into the buffer water suction well 31 which is connected with the water suction pipe of the clean water pressurizing pump room 32, the pump room is provided with 4 (3 uses 1) high-power clean water pressurizing pumps, the pressurized clean water enters into the clean water conveying pipeline 35 with the total length of about 17km after being metered by the matched clean water valve flowmeter 33 and exhausted by combining the well and the exhaust valve 34, and the clean water enters into the upstream direction 11 (1) of the lakeshore^#～11^#) The clear water returning and replenishing point 36 conveys clear water, and the starting end caliber DN2200 and the tail end caliber DN800 of the clear water conveying pipeline 35. The clear water flow parameters of the lake returning water replenishing points are as follows:

the detailed water quantity distribution calculation of the self-circulation supply running water of the lake: after hydrodynamic simulation analysis is performed through the MIKE21 software model, the lake returning water quantity of the clear water lake returning point of the embodiment 11 is drawn up and is from the near to the far 1^#～11^#The flow of the point location is respectively: 5.1, 4.7, 4.4, 4.2, 4.0, 3.8, 3.7, 3.8, 3.9 ten thousand meters³D, total 45 ten thousand m³/d。

When the water source plant completes and is filled with water, 1^#～11^#The clear water returns to a sub-clear transparent area which is gradually enlarged near a lake water replenishing point 36, the work of introducing native submerged plants and/or pollution-resistant favorite clear water plants is carried out, other work arrangements are also implemented one by one, the work comprises planting emergent aquatic plants at shallow water and on the bank, constructing ecological floating islands at lakes, also comprising native other suitable floating-leaf plants, and putting in proper amount of native fish fries at proper time, comprising other suitable aquatic animals, insects and the like, and preparing the work of harvesting, fishing and other measures for algae and aquatic plants;through the measures for constructing the biological diversity, submerged plants and the like thrive under the conditions of underwater photosynthesis and nitrogen and phosphorus nutrient nourishment carried by water flow, and the water ecosystem recovers stronger natural purification capacity by matching with other ecological measures, so that a clear and beautiful grass type clear water lake with shallow fish flying bottom is created.

Through simulation analysis, after 6 months of putting the bypass purification engineering into production and continuously developing the bypass purification engineering in cooperation with water ecological reconstruction work, the water quality in the center of the lake and at the upstream of the lake is obviously improved, and part of water quality indexes are superior to III class water standard values of surface water environmental quality standard and stably reach IV class water standard values and COD_Cr4.8mg/L is reduced, TP is reduced to be less than 0.04mg/L, and TN is less than 1.4 mg/L; with the gradual recovery of aquatic vegetation, TN is estimated to be less than 1.0mg/L after 2.5-4 years, because the removal of TN in lake water mainly depends on the assimilation removal of aquatic organisms, particularly aquatic plants. It is expected that the annual average transparency of lake water will reach 0.5m, 0.6m after 2 years, 0.7m after 3 years, and more than 0.8m after 4 years after 1 year of project commissioning and continuous water ecology reconstruction.

The lake of the embodiment circularly supplies the running water per m³The direct cost of the power consumption (including lake water entering the factory for lifting and pressurized conveying), the medicine consumption, the labor cost, the maintenance cost and the like is 0.40 yuan in total (the daily expenditure is only 6516 ten thousand yuan per year, and the maintenance cost is 3 days per year), and the construction investment, the occupied land, the operation cost and the like can be saved by about 55 percent compared with the cross-river-area ecological water supplement or tap water supplement of other systems, so the technical and economic benefits of the utility model are very obvious. The project adopts the grass-type lake regeneration system technology to obtain good lake pollution treatment and lake enhanced regeneration effect and technical and economic effect.

As described above, the present invention can be preferably implemented by innovative thinking, overall calculation, and detailed design.

From the two embodiments, the grass type lake regeneration system can forcibly and continuously reduce pollutants, self-supply running water which is rich in oxygen and clean and has the transparency of more than or equal to 12m, and can exchange water or supplement water in large quantity by using tap water without depending on external ecological water diversion, only a physicochemical treatment purification facility needs to be arranged at a proper position beside a lake, a small amount of medicament (such as PAC) is added for treatment according to the annual dynamic change condition of the lake water quality, and then the water ecological reconstruction work is continuously carried out in a coordinated manner, so that the lake water can be kept stably in a clear state, a beautiful state with poor water and shallow fish flight and a water body standard which is not higher than surface water III, and the cost is completely acceptable on the urban operation level. Therefore, compared with other lake pollution treatment and lake water regeneration systems, the system has the advantages of manual controllability, stability, reliability, low construction cost and low operation cost.

In conclusion, the grass-type lake regeneration system has the advantages of novel, unique, simple, direct and reliable conception, strong engineering implementation, universal applicability and wide market application prospect. Especially in the practice of continuously advancing national ecological protection strategy in China, if the utility model is widely applied to urban lake pollution treatment and water environment ecological construction projects of beautiful water environment, the utility model will make great contribution to global carbon emission reduction, therefore, the macroscopic and microscopic economic benefits, environmental benefits and social benefits of the utility model are very obvious, and the sustainable development value and socialist ecological civilization value are fully reflected.

The protective scope of the present invention is not limited to the above-described embodiments, and it is apparent that various modifications and variations can be made to the present invention by those skilled in the art without departing from the scope and spirit of the present invention. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (7)

1. A grass-type lake regeneration system is characterized in that: comprises a multi-point water taking system for the downstream algae-containing turbid water of the lake, a shore-based physicochemical treatment and purification system, a multi-point lake returning system for the delivery upstream of a clear water pipeline, a grass-type water ecological steady-state expansion system and a matched auxiliary system which are connected in sequence; the purification system comprises a high-level grid distribution pool, the high-level grid distribution pool is sequentially connected with a coagulating sedimentation clarification air flotation algae removal pool, a homogeneous filter material air-water backwashing sand filter pool and a backwashing pump room through connecting pipelines, and the backwashing pump room at the rear end is connected with a buffering water suction well of the lake returning system through connecting pipelines; the grass type water ecology steady expansion system comprises native submerged plants introduced in a clear water area, emergent aquatic plants planted at shallow water and on the bank side, and native fry thrown in a water area.

2. The grass-type lake recycling system of claim 1, wherein: the water intake system comprises a lake downstream or a main wind direction downwind position, and a plurality of water intake wells which are approximately equal in distance are arranged on a cross section vertical to the overall flow direction of the lake, a surface water intake is arranged at the top of each water intake well, the lower parts of the water intake wells which are partially positioned in deep water are close to a lake bed, and a lower water intake is arranged, each water intake well is sequentially connected through a lake bottom water conduit, and finally connected with a water intake pump room inlet positioned on the lake bank side, and the water intake pump room outlet is connected with a high-position grid water distribution tank positioned on the bank through a water intake valve flowmeter and a water intake pressure conduit.

3. A grass-type lake recycling system as claimed in claim 2, wherein: the number of water intake wells is not less than 2, the number of surface layer water intake ports is not less than 2, and the number of lower layer water intake ports is not less than 1.

4. The grass-type lake recycling system of claim 1, wherein: the purification system also comprises a grid cleaner, a coagulant adding machine, a mud scraping and sucking machine, a finger-shaped water collecting tank and an air floatation algae scraping machine.

5. The grass-type lake recycling system of claim 1, wherein: the lake returning system comprises a buffering water suction well, wherein the buffering water suction well is connected with a clean water pressurizing pump room through a pipeline, then passes through a clean water valve flowmeter, a combination well and an exhaust valve, and then passes through a long-distance clean water conveying pipeline to convey clean water to a lake returning water replenishing point at the upstream direction of a lake or a main wind direction upward to a lake bank.

6. The grass-type lake recycling system of claim 5, wherein: the quantity of the clear water lake-returning water replenishing points is not less than 5, and the water replenishing points are set into various forms of lake-entering water-fall waterfall water scenes which serve as water replenishing points, and the lake-returning clear water is continuously oxygenated.

7. The grass-type lake recycling system of claim 1, wherein: the dissolved oxygen DO of the lake returning clear water is more than or equal to 5mg/L, the transparency is more than or equal to 12m, and the turbidity is less than or equal to 1NTU immediately before the lake returning clear water enters the lake.

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