CN104176882B - A kind of inlet method and device improving artificial filtration system nitric efficiency - Google Patents

Abstract

The invention discloses a water intake method and device for improving the denitrification efficiency of an artificial infiltration system. The steps are: A. Raw sewage collection and pretreatment: the raw sewage in the diversion ditch is controlled by a control valve and a sewage pump connected to a sedimentation tank The raw sewage is pumped into the sedimentation tank, and the suspended solids and sediment are removed in the sedimentation tank; B. Water level increase: the pretreated raw sewage in the sedimentation tank is raised to the high level tank by the sewage pump; C. Advanced treatment: high level After the tank is controlled by the regulating valve, the pretreated water is in the filling layer of the quick seepage tank to achieve sewage treatment. The sedimentation tank is connected to the drainage ditch through the sewage pump and the control valve on the pipeline. The sewage pump is connected to the sedimentation tank. It is connected with the quick seepage pool, and the perforated water distribution pipe is connected with the outlet pipe. It ensures the removal of nitrogen, phosphorus and COD by the CRI system. The structure is simple, the use is convenient, and the efficient purification of sewage can be realized.

Description

Water intake method and device for improving denitrification efficiency of artificial infiltration system

technical field

The invention relates to the technical field of removing nitrogen in sewage by using an artificial rapid infiltration system, more specifically relates to a water intake method for improving the denitrification efficiency of an artificial rapid infiltration system, and also relates to a method for improving the denitrification efficiency of an artificial rapid infiltration system The water inlet device is suitable for treating domestic sewage in most rural areas and small towns in my country.

Background technique

With the rapid economic development and increasing human activities, more and more industrial waste water, domestic sewage, domestic garbage and pesticides and other pollutants are discharged into natural water bodies, causing varying degrees of pollution to water resources. While people are pursuing economic interests, the society's demand for water continues to increase. However, the environmental protection awareness of Chinese residents is weak, the precipitation varies greatly between the north and the south, and the low water use efficiency continues to aggravate the tension between the supply and demand of my country's water resources, resulting in the problem of my country's water resources. It is also developing towards diversification, the problem of point source and non-point source pollution is becoming more and more prominent, sudden water pollution incidents occur frequently, water ecological security is threatened, and the superposition and cumulative impact of water problems are becoming more and more serious.

The implementation of harmless and resourceful sewage treatment, the combination of treatment and utilization, and the parallel technology of artificial treatment and natural treatment are completely in line with the current national conditions of our country. Specifically, large cities have a large amount of domestic sewage, complex components, and strong municipal economic bearing capacity, so manual treatment should be the main approach, and centralized treatment should be implemented; while domestic sewage in small and medium-sized cities, towns, and rural areas has simple components, and the following methods should be implemented: Harmless and resource-based sewage treatment policies based on land treatment and other technologies. It can be foreseen that the implementation of harmless and resourceful sewage treatment will, on the one hand, greatly increase the limited amount of water resources in our country; , The strategic goal of comprehensive and sustainable social development.

As a kind of land treatment system, artificial rapid infiltration system (CRI system) has the advantages of not being restricted by geographical terrain, small footprint, low investment cost and high treatment load. Therefore, it is necessary to conduct in-depth research to make it a mature, economical and efficient sewage land treatment process, so as to contribute to domestic sewage and polluted river water treatment and sewage resource utilization in small towns in my country. As a new technology, the artificial rapid infiltration system is still insufficiently aware of the influence of environmental factors and operating parameters on the treatment effect, and the research on its pollutant removal mechanism is not sufficient. These will affect the stable operation of the CRI system in actual projects. cause adverse effects.

Therefore, there are still many things to be improved about the specific operating parameters and actual operating efficiency of the CRI system. At present, the research on optimizing the treatment efficiency of the CRI system is mainly based on the selection of the adsorption medium and the design of the CRI structure, and there are few studies on the influence of the water inlet method on the treatment efficiency of the CRI system. According to our previous research, adopting a segmented water intake method that is different from the traditional water intake method can effectively improve the denitrification efficiency of the CRI system (see Journal of Environmental Engineering, Wang Guihe, Fang Tao et al. Effects on nitrogen efficiency"). However, the staged water inlet method has the disadvantage of low hydraulic load, and due to the different microenvironments of different layers of the quick seepage tank, it is necessary to select an appropriate staged water inlet position and water inlet ratio for different water quality in order to improve the CRI system. The removal rate, which increases the workload in the actual operation process.

In the present invention, the applicant proposes a water inlet method and device for improving the denitrification efficiency of the CRI system.

Contents of the invention

The purpose of the present invention is to provide a water inlet method for improving the denitrification efficiency of the artificial rapid infiltration system, which can improve the denitrification efficiency of the artificial rapid infiltration system. Different from the traditional downflow water inflow method, that is, sewage passes through the percolation medium from top to bottom, the upflow water inflow method involved in the present invention adopts the method of bottom water inflow and surface water outflow in the CRI system. The removal rate of ammonia nitrogen and total nitrogen by the CRI system is significantly higher than that of the conventional water inflow method by adopting the upstream water inflow method, and the removal rate of ammonia nitrogen and total nitrogen increases gradually with the increase of influent load. The conventional water inflow method of the CRI system has a high removal rate of total phosphorus and COD, but a low removal rate of nitrogen. Combining the proposed upstream influent with the traditional downstream, the method is easy to implement and easy to operate, which ensures the removal of nitrogen, phosphorus and COD by the CRI system.

Another object of the present invention is to provide a water inlet device for improving the denitrification efficiency of the artificial rapid infiltration system. The device has a small footprint, low cost, simple structure and convenient use, and can realize efficient purification of sewage.

A water intake method for improving the denitrification efficiency of an artificial infiltration system, the steps of which are:

(1) Raw sewage collection and pre-treatment: The raw sewage in the drainage ditches is pumped into the sedimentation tank by the control valve and the sewage pump connected to the sedimentation tank. The microorganisms attached to the surface and their own absorption of nutrients can remove part of N, P, BOD and COD;

(2) Water level raising: The pretreated raw sewage in the sedimentation tank is lifted to the high level tank by the sewage pump, and the water stored in the high level tank can directly enter the quick seepage tank under the action of gravity through the control valve when needed.

(3) Advanced treatment: After the high-level tank is controlled by the regulating valve, the water enters the water inlet pipe, and then distributes the water evenly through the perforated water distribution pipe. 2mm natural river sand, the second layer is natural river sand with a particle size of 2-4mm, the third layer is pebbles with a particle size of 20-100mm, the fourth layer is coarse sand with a particle size of 4-8mm, and the fifth layer is a particle size 20-100mm pebbles) infiltrate from the bottom to the surface, and finally the water from the surface enters the outlet pipe, and the treated water is discharged into the drainage ditch again to achieve the effect of advanced sewage treatment.

A water inlet device for improving the denitrification efficiency of an artificial rapid infiltration system: the device includes a sedimentation tank, a high level tank, a quick seepage tank, a control valve, a drainage ditch, raw sewage, a sewage pump, a water inlet pipe, a perforated water distribution pipe, Outlet pipes and fillers (the surface layer is natural river sand with a particle size of 1.5-2mm, the second layer is natural river sand with a particle size of 2-4mm, the third layer is pebbles with a particle size of 20-100mm, and the fourth layer is a particle size of 4- 8mm coarse sand, the fifth layer is pebbles with a particle size of 20-100mm). It is characterized in that: the sedimentation tank is connected with the drainage ditch through the sewage pump and the control valve on the pipeline, and the drainage ditch regulates the water volume of the raw sewage entering the sedimentation tank through the control valve, and is connected with the sedimentation tank through the sewage pump, and the raw sewage is in the sedimentation tank After sedimentation, the outlet water is connected to the high-level tank through the sewage pump, and the water is lifted to the high-level tank, and the high-level tank is connected to the water inlet pipe. Connected, the water inlet pipe is connected to the perforated water distribution pipe at the bottom of the quick seepage tank, and the perforated water distribution pipe distributes the water to the quick seepage tank, and after staying for 1 day, it is directly discharged into the drainage ditch through the outlet pipe.

The quick seepage pool is a cement pool with a height of 2m and a length and width of 1m, which is filled with adsorption fillers, and the depth of the fillers is 1.7m (the filler layer is divided into five layers from top to bottom: the upper layer is filled with natural 400mm particle size 1.5-2mm River sand, the second layer is filled with 500mm natural river sand with a particle size of 2-4mm, the third layer is filled with 100mm pebbles with a particle size of 20-100mm, the fourth layer is filled with 400mm coarse sand with a particle size of 4-8mm, and the fifth layer Fill with 300mm pebbles with a particle size of 20-100mm), and set perforated water distribution pipes at different depths of the quick seepage pool (1.7m in the bottom layer and 0.2m in the surface layer), and connect with the high level tank through the water inlet pipe. In specific implementation, when using the upward flow water inlet method, the perforated water distribution pipe at a depth of 0.2m in the surface layer is closed, and the sewage enters the perforated water distribution pipe at a depth of 1.7m in the bottom layer through the water inlet pipe, and the sewage after uniform water distribution flows from the bottom layer of the packing layer Infiltrate to the surface for treatment, and the treated water is discharged from the surface 0.2m into the outlet pipe; when it is necessary to compare the conventional water inlet method, the perforated water distribution pipe at a depth of 1.7m at the bottom is closed, and the sewage enters the surface 0.2m deep through the water inlet pipe The perforated water distribution pipe at the place, the sewage after uniform water distribution seeps down from the surface of the packing layer to the bottom layer for treatment, and the treated water is discharged from the bottom 1.7m into the outlet pipe.

The specific construction process of a water inlet device that improves the denitrification efficiency of the artificial rapid infiltration system is as follows:

(1) Construction of artificial rapid infiltration system, domestic sewage is settled through sedimentation tank, high level tank and quick infiltration tank;

(2) The layout of the water inlet and outlet pipes of the quick osmosis tank in the artificial rapid infiltration system. The water inlet and outlet pipes are laid on the surface and bottom layer of the quick osmosis tank, and the water inlet pipes are porous water distribution pipes.

(3) Screening of infiltration media in quick infiltration tanks. Commonly used media fillers include activated carbon, natural zeolite, biological ceramsite, steel slag, and coarse sand (with a particle size of 4-8mm).

(4) After the rapid infiltration tank is successfully coated with ordinary domestic sewage, the operating parameters of the artificial rapid infiltration system are optimized, including the wet-to-dry ratio (wet/dry = 4:1-1:4), the thickness of the percolation layer (1- 2m), hydraulic load (0.5-5m/d), etc.

(5) The CRI system adopts the traditional water inlet method and the upflow water inlet method respectively, and compares the effects of the two water inlet methods on the denitrification efficiency of the artificial rapid infiltration system.

(6) After the influent water stays in the quick seepage tank for 1 day, the influent water and effluent water samples are taken separately, the total nitrogen and ammonia nitrogen content in the water samples are tested, and the removal rate is calculated, and a better water inflow method is obtained according to the removal rate.

TN: Alkaline potassium persulfate oxidation-UV spectrophotometry; NH ₃ -N: Nessler's reagent colorimetry;

Removal rate = (influent water quality - effluent water quality) / influent water quality × 100%.

Compared with the prior art, the present invention has the following advantages and effects:

The invention can effectively improve the denitrification efficiency of the artificial rapid infiltration system, thereby making greater contributions to the treatment of polluted water bodies in rural areas and small towns, and also provides ideas and references for further perfecting and improving the treatment effect of the artificial rapid infiltration system. , the upstream water inflow method involved in the present invention has the following advantages:

(1) The CRI system adopts the upstream water intake method and inherits the advantages of the CRI system under the traditional water intake method, such as not being restricted by geographical terrain, small footprint, low investment cost, and high processing load.

(2) Adopting the upstream water inlet method is conducive to the sewage filling the tank more evenly and fully contacting the filler, which is conducive to ensuring the stability of the effluent water quality to a certain extent. In addition, the water effluent from the surface layer of the CRI system is conducive to convection with the air. Thereby increasing the ratio of oxygen exchange and ensuring a certain concentration of oxygen in the effluent.

(3) According to local conditions, in-situ repairs can be carried out near rivers with sewage discharge, without causing secondary pollution, and have low requirements for sewage pretreatment.

(4) Since the surface layer of the quick seepage tank is more likely to be in contact with the atmosphere, the reoxygenation process is more likely to occur, so as to ensure that the surface layer of the quick seepage tank contains a certain concentration of oxygen, which is conducive to the progress of nitrification and improves the removal rate of ammonia nitrogen. It is estimated that the removal rate of ammonia nitrogen can be Reach more than 70%.

Description of drawings

Fig. 1 is a schematic flow chart of a water intake method for improving the denitrification efficiency of an artificial infiltration system.

The raw sewage 1 is lifted to the sedimentation tank A by the sewage pump 2 and then raised to the high level tank B again after standing still for 24 hours. The pretreated sewage flows from the high level tank B along the pipeline into the quick osmosis tank C, and after being treated by the quick osmosis tank C for 1 day, the water comes out.

Fig. 2 is a schematic diagram of the structure of a quick osmosis tank C.

In the CRI system in this embodiment, the depth of the C filler in the quick seepage tank is 1.7m (the filler layer is divided into five layers from top to bottom: the upper layer is filled with natural river sand with a particle size of 400mm and a particle size of 1.5-2mm, and the second layer is filled with a particle size of 500mm. 2-4mm natural river sand, the third layer is filled with 100mm pebbles with a particle size of 20-100mm, the fourth layer is filled with 400mm coarse sand with a particle size of 4-8mm, and the fifth layer is filled with 300mm pebbles with a particle size of 20-100mm. )

Fig. 3 is a schematic diagram of a main treatment device of an artificial infiltration system.

Including sedimentation tank A, high level tank B, quick seepage tank C, control valve D, drainage ditch E, control valve F, raw sewage 1, sewage pump 2, sewage pump 3, water inlet pipe, 4, perforated water distribution pipe 5. Outlet pipe 6, filler 7 (the surface layer is natural river sand with a particle size of 1.5-2mm, the second layer is natural river sand with a particle size of 2-4mm, the third layer is pebbles with a particle size of 20-100mm, and the fourth layer is Coarse sand with a particle size of 4-8mm, and the fifth layer is pebbles with a particle size of 20-100mm). The connection relationship is as follows: the drainage ditch E regulates the water volume of the raw sewage 1 entering the sedimentation tank A through the control valve D, and is connected with the sedimentation tank A through the sewage pump 2. After the raw sewage 1 settles in the sedimentation tank A, the effluent passes through the sewage pump 3 It is connected with the high-level tank B, lifts water to the high-level tank B, and the high-level tank B is connected with the water inlet pipe 4, and the outlet water of the high-level tank B is controlled by the regulating valve F to control the amount of water entering the water inlet pipe 4, and through the water inlet pipe 4 and the quick infiltration Pool C is connected, the water inlet pipe 4 is connected to the perforated water distribution pipe 5 at the bottom of the quick seepage tank C, and the perforated water distribution pipe 5 distributes the water to the quick seepage tank C, and after staying for 1 day, it is directly discharged into the drainage ditch E through the outlet pipe 6 .

detailed description

Specific embodiments of the present invention will be further described below.

Example 1:

According to Fig. 1, it can be seen that a water intake method for improving the denitrification efficiency of the artificial infiltration system, the steps are:

(1) Raw sewage collection and pre-treatment: The raw sewage 1 in the drainage ditch E is pumped into the sedimentation tank A by the control valve D connected to the sedimentation tank A and the sewage pump 2; the raw sewage 1 can be removed in the sedimentation tank A and suspended At the same time, the microorganisms attached to the surface of floating plants and their own absorption of nutrients can remove part of N, P, BOD and COD;

(2) Water level raising: The pretreated raw sewage 1 in the sedimentation tank A is lifted to the high level tank B by the sewage pump 3, and the water stored in the high level tank B can pass through the control valve F under the action of gravity when needed Direct access to quick seepage pool C.

(3) Advanced treatment: After the high-level tank B is controlled by the control valve F to control the water outlet, it enters the water inlet pipe 4, and then distributes the water evenly through the perforated water distribution pipe 5. , divided into five layers from top to bottom, the surface layer is natural river sand with a particle size of 1.5-2mm, the second layer is natural river sand with a particle size of 2-4mm, the third layer is pebbles with a particle size of 20-100mm, and the fourth layer is Coarse sand with a particle size of 4-8mm, and the fifth layer is pebbles with a particle size of 20-100mm) infiltration from the bottom layer to the surface layer, and finally the water from the surface layer enters the outlet pipe 6, and the treated water is discharged into the drain Ditch E achieves the effect of advanced sewage treatment.

Example 2:

According to Figure 2 and Figure 3, it can be seen that a water inlet device for improving the denitrification efficiency of the artificial rapid infiltration system: it includes a sedimentation tank A, a high level tank B, a quick seepage tank C, a control valve D, a drainage ditch E, and a control valve F, raw sewage 1, sewage pump 2, sewage pump 3, water inlet pipe 4, perforated water pipe 5, water outlet pipe 6, filler 7 (the surface layer is natural river sand with a particle size of 1.5-2mm, and the second layer is a particle size of 2 -4mm natural river sand, the third layer is pebbles with a particle size of 20-100mm, the fourth layer is coarse sand with a particle size of 4-8mm, and the fifth layer is pebbles with a particle size of 20-100mm). It is characterized in that: the sedimentation tank A is connected to the drainage ditch E through the sewage pump 2 and the control valve D on the pipeline, and the drainage ditch E regulates the water volume of the raw sewage 1 entering the sedimentation tank A through the control valve D, and passes through the sewage pump 2 and the drainage ditch E. The sedimentation tank A is connected. After the raw sewage 1 settles in the sedimentation tank A, the outlet water is connected to the high-level tank B through the sewage pump 3, and the water is lifted to the high-level tank B. The high-level tank B is connected to the water inlet pipe 4, and the water outlet of the high-level tank B is controlled. The valve F controls the amount of water entering the water inlet pipe 4, the water inlet pipe 4 is connected to the quick seepage tank C through the regulating valve F on the pipe, the water inlet pipe 4 is connected to the perforated water distribution pipe 5 at the bottom of the quick seepage tank C, and the perforated water distribution pipe 5 Connected with the water outlet pipe 6, the perforated water distribution pipe 5 distributes the water to the quick seepage pool C, and after staying for 1 day, it is directly discharged into the drainage ditch E through the water outlet pipe 6.

The elevated tank B is a cuboid cement pool with a height of 6m and a length and width of 2m. The elevated tank can be used to store pretreated sewage and can directly rely on gravity to supply water to the quick seepage tank. The water depth of elevated tank B is maintained above 4m to ensure sufficient discharge load.

The perforated water distribution pipe 5 is a vertical and three horizontal water pipes at a depth of 1.7m in the bottom layer (a small hole with a diameter of 2mm is evenly distributed on the water pipe), one of the vertical pipes is connected to the water inlet pipe 4, and the surface perforated water distribution pipe 5 Same as the deep layer (bottom perforated water distribution pipe 5 is used in the upward flow water intake method, and the surface layer perforated water distribution pipe 5 is used in the downward flow water intake method).

The quick seepage pool C is a cement pool with a height of 2m and a length and width of 1m, which is filled with adsorption filler 7, and the depth of the filler 7 is 1.7m (the filler layer is divided into five layers from top to bottom: the upper layer is filled with 400mm particle size of 1.5- 2mm natural river sand, the second layer is filled with 500mm natural river sand with a particle size of 2-4mm, the third layer is filled with 100mm pebbles with a particle size of 20-100mm, and the fourth layer is filled with 400mm coarse sand with a particle size of 4-8mm. The fifth layer is filled with 300mm pebbles with a particle size of 20-100mm), and perforated water distribution pipes 5 are installed at different depths of the quick seepage pool C (1.7m in the bottom layer and 0.2m in the surface layer), and pass through the water inlet pipe 4 and the high level tank B is connected. During specific implementation, when adopting the method of upstream water inflow, close the perforated water distribution pipe 5 at a depth of 0.2m in the surface layer, and the sewage enters the perforated water distribution pipe 5 at a depth of 1.7m in the bottom layer through the water inlet pipe 4, and the sewage after uniform water distribution flows from The bottom layer of the packing layer is infiltrated to the surface layer for treatment, and the treated water is discharged from the surface layer 0.2m into the outlet pipe 6; when it is necessary to compare the conventional water inlet method, the perforated water distribution pipe 5 at a depth of 1.7m in the bottom layer is closed, and the sewage passes through the water inlet pipe 4 Enter the perforated water distribution pipe 5 at a depth of 0.2m in the surface layer, and the sewage after uniform water distribution seeps down from the surface layer of the packing layer to the bottom layer for treatment, and the treated water is discharged from the bottom layer 1.7m into the outlet pipe 6.

The specific construction process of a water inlet device that improves the denitrification efficiency of the artificial rapid infiltration system is as follows:

(1) Construction of the artificial rapid infiltration system. The raw sewage 1 is lifted to the sedimentation tank A by the sewage pump 2 and left to stand for 24 hours.

The built pilot settling tank A is 2m in height, 4m in length and 3m in width, and the water depth is maintained at 1-1.5m, and the sewage stays in it for 1 day.

The elevated tank B is a cuboid with a height of 6m, a length and a width of 2m, and a water depth of more than 4m to ensure sufficient discharge load.

The built quick seepage tank C consists of 7 individual tanks (6 for use and 1 for standby), with a height of 2m, a length and a width of 1m, and a depth of 1.7m for the filler, with a total of 5 layers of filler, which are made of natural river sand from the surface layer to the bottom layer ( fine sand), natural river sand (medium sand), pebbles, coarse sand, pebbles. The thickness of each layer is 0.4, 0.5, 0.1, 0.4, 0.3 meters from top to bottom.

(2) Arrangement of the water inlet and outlet pipes 6 of the quick seepage pool C in the artificial rapid infiltration system, the water inlet pipe 4 is set in the quick seepage tank C, the bottom water inlet method is adopted in the present invention, and the pretreated water passes through the elevated tank B After flowing out, it enters the water inlet at the bottom of the quick osmosis tank C through the pipeline. The water inlet pipe 5 is a multi-step water pipe with three vertical and three horizontal steps. After staying in the infiltration tank C for 1 day, water is discharged from the outlet pipe 6, which is set in the middle of the surface medium, that is, the surface filler is 20 cm deep.

(3) Screening of the percolation medium in the quick permeation tank C. Commonly used media include activated carbon, natural zeolite, biological ceramsite, steel slag, and coarse sand. The adsorption medium used in the fourth layer in Example 1 of the present invention is coarse sand (particle size 4-8mm ), its porosity and water content are 39.01% and 11.59%, respectively.

(4) After using ordinary domestic sewage to coat the quick infiltration tank with film, optimize the operating parameters of the artificial rapid infiltration system, including the wet/dry ratio (wet/dry = 4:1-1:4), the thickness of the infiltration layer (1-2m ), hydraulic load (0.5-5m/d), etc. On the basis of existing research (Journal of Environmental Engineering, 2012, Fang Tao et al., Optimizing process parameters of a new type of artificial rapid infiltration system for treating village and town sewage), the wet-dry ratio is selected as 1:2 in this example, and the thickness of the infiltration layer is 1.7m , the hydraulic load is 0.8-1.2m/d operating parameters. The optimal hydraulic load of the control pond is 1m/d with conventional water inflow. (Refer to Journal of Environmental Engineering, Wang Guihe, Fang Tao, etc. "The Influence of Staged Water Intake Method on the Nitrogen Removal Efficiency of Artificial Rapid Seepage System")

(5) The CRI system adopts the traditional water inflow method and the upflow water inflow method respectively. After the influent water stays in the quick seepage tank C for 1 day, take the influent and effluent water samples separately, test the total nitrogen and ammonia nitrogen of the water samples, and calculate the removal rate. According to the removal rate, a better water inlet method is obtained.

TN: Alkaline potassium persulfate oxidation-UV spectrophotometry; NH ₃ -N: Nessler's reagent colorimetry;

Removal rate = (influent water quality - effluent water quality) / influent water quality × 100%.

(6) Experimental results and analysis

Three parallel experiments were performed, and the experimental results were expressed as mean ± standard error (Mean ± SD), as shown in Table 1 below.

Table 1 Removal rate of pollutants under different influent loads

Table 1 shows the removal rate of pollutants in the CRI system using the upflow inflow method and the conventional inflow method under different influent loads. It can be seen from the table that the removal rate of ammonia nitrogen and total nitrogen through the upstream water inflow method is better than that of the conventional water inflow method, and the removal rate of ammonia nitrogen and total nitrogen increases gradually with the increase of the influent load. Especially in the removal of total nitrogen, when the influent load is 1.2m/d, the removal rate of total nitrogen by adopting the upflow method is 26.9% higher than that of conventional influent.

According to the removal rate of ammonia nitrogen and total nitrogen by the upflow inflow CRI system under different inflow loads, it can be seen that appropriately increasing the inflow load under the upflow inflow method is beneficial to the removal of nitrogen by the CRI system.

(7) Final result

The above experimental results show that the nitrogen removal efficiency of the CRI system can be effectively improved to a certain extent by adopting the method of upstream water inflow. And the appropriate increase of the influent load under the upflow influent method is beneficial to the removal of nitrogen by the CRI system. Therefore, the upstream water inlet method and device of the present invention can be combined with the conventional water inlet method and device of the CRI system, so as to achieve simultaneous removal of nitrogen, phosphorus and COD. The method is easy to operate and easy to operate, which provides a reference for the optimization and improvement of the CRI system.

Claims (4)

1. improve an inlet method for artificial filtration system nitric efficiency, the steps include:

1) raw waste water is collected and pre-treatment: the raw waste water in ejectment irrigation canals and ditches (E) is extracted by the first controlling valve (D) and the first sump pump (2) that are connected settling tank (A) and enters settling tank (A), raw waste water (1) removes wherein suspended substance and silt in settling tank (A), simultaneously pleuston surface attachment microorganism and itself is to the absorption of nutritive salt, remove part N, P, BOD and COD;

2) water level promoting: water extraction is risen to header tank (B) by the second sump pump (3) by pretreated raw waste water (1) in settling tank (A), the water be stored in header tank (B) directly enters under gravity through the second controlling valve (F) and oozes pond (C) soon;

3) advanced treatment: header tank (B) is after the second controlling valve (F) controls water outlet, enter inlet channel (4), perforated water distributor (5) water distribution uniformity again, pretreated water is oozing pond (C) packing layer soon from bottom to top layer diafiltration, finally enter outlet conduit (6) by top layer water outlet, water after process is entered ejectment irrigation canals and ditches (E), reaches advanced treatment of wastewater.

2. one kind is improved the water feed apparatus of artificial rapid infiltration system nitric efficiency, it is characterized in that: it comprises settling tank (A), header tank (B), ooze pond (C) soon, first controlling valve (D), ejectment irrigation canals and ditches (E), second controlling valve (F), first sump pump (2), second sump pump (3), inlet channel (4), perforation water distributor (5), outlet conduit (6), filler (7), it is characterized in that: settling tank (A) is connected with ejectment irrigation canals and ditches (E) with the first controlling valve (D) by the first sump pump (2) on pipeline, first sump pump (2) is connected with settling tank (A), water outlet is connected with header tank (B) through the second sump pump (3), header tank (B) is connected with inlet channel (4), inlet channel (4) by the second controlling valve (F) on pipeline with ooze pond (C) soon and be connected, inlet channel (4) with ooze pond (C) bottom water distributor (5) of boring a hole soon and be connected, perforation water distributor (5) is connected with outlet conduit (6).

3. a kind of water feed apparatus improving artificial rapid infiltration system nitric efficiency according to claim 2, it is characterized in that: described pond (C) of oozing soon is be highly 2m, length and width are the cement pit of 1m, wherein be filled with adsorption stuffing (7), the degree of depth of filler (7) is 1.7m, packing layer divides five layers from top to bottom: it is the natural river sand of 1.5-2mm that 400mm particle diameter is filled on upper strata, it is 2-4mm natural river sand that the second layer fills 500mm particle diameter, it is the pebbles of 20-100mm that third layer fills 100mm particle diameter, 4th layer is filled 400mm particle diameter is the coarse sand of 4-8mm, it is the pebbles of 20-100mm that layer 5 fills 300mm particle diameter.

4. a kind of water feed apparatus improving artificial rapid infiltration system nitric efficiency according to claim 2, it is characterized in that: described perforation water distributor (5) bottom is vertical three horizontal water tubes, and wherein a longitudinal tubule (L tubule) is connected with inlet channel (4).