Under natural conditions, water bodies of lakes and rivers have different water quality problems, and water body pollution is mainly invasion of pollution sources, such as: the invasion of domestic garbage, the penetration of chemical fertilizers and pesticides, the decay of animal and plant bodies, the excretion of aquatic plants, the consumption of a large amount of dissolved oxygen during the decomposition of organic matters in the water body, and the lack of necessary circulation and too low dissolved oxygen of the water body, so that the water body gradually loses the self-purification capacity. The continuous increase of nitrogen and phosphorus in the water body leads to eutrophication of the water body, gradual greening of the water body and excessive growth of algae, and finally leads to the phenomenon of water bloom, generation of peculiar smell and easy blackening and smelling.
The commonly used lake sewage treatment method comprises the following steps: building a dam, conducting water, changing water and dredging sludge; microwave purification, circular filtration, zeolite adsorption and coagulation, microorganism or sterilization algicide adding, tubular membrane treatment process, ecological floating island and the like.
Although the methods of building dams, introducing water for changing water, dredging sludge and the like can effectively improve the quality of lake water, the construction period is long, the process is very complex and the cost is high; the microwave purification, the circular filtration, the zeolite adsorption and the coagulation can effectively remove the pollutants such as phosphorus element, COD and the like, but can not remove the total nitrogen; the method is only suitable for high-concentration black and odorous water bodies, cannot reduce the concentration of pollutants to a lower level, can remove nitrogen, phosphorus and COD by a tubular membrane treatment process, but has the problems of high investment cost and secondary pollution of concentrated water.
The ecological floating island is an artificial floating island which aims at eutrophication water quality and degrades COD, nitrogen and phosphorus contents in water by utilizing the principle of ecological engineering. The growth and propagation process of the aquatic plants needs a large amount of nutrition, the oxygen-rich environment formed by the root system of the ecological floating island plants in water and the biomembrane on the surface of the root system can efficiently degrade the content of COD, nitrogen and phosphorus in water, and the polysaccharide generated by microorganisms in the root system membrane can effectively adsorb suspended matters in water. It can greatly raise water transparency, and can effectively improve water quality index, specially has good inhibiting effect for algae. The ecological floating island utilizes the root system of the plant to absorb eutrophic substances in water, so that the nutrition of the water body is transferred, and the phenomena of water body fishy smell and eutrophication caused by the insufficient closing or self-circulation of the water body are reduced.
however, the ecological floating island has seasonal influence, and the purification effect of the aquatic plants on the lake water in the low-temperature environment is weakened, so that the technology cannot realize continuous sewage purification. Partial data show that the aquatic plants in the floating island system have good purification effect on water quality in spring, summer and autumn, but the contents of nitrogen, phosphorus and COD in water in winter are basically unchanged, and the plants approximately stop growing. Therefore, attention must be paid to the use restriction of the ecological floating island system in different seasons and the case of sudden deterioration of water quality due to an emergency such as rainfall.
SUMMERY OF THE UTILITY MODEL
In order to solve the technical problem, the utility model provides a system for adopt combination technology to purify lake water.
The utility model adopts the technical proposal that: a system for purifying lake water by adopting a combined process is characterized in that: comprises an artificial floating island and/or a movable ultrafiltration membrane device;
The artificial floating island has a three-layer structure and comprises an upper-layer floating island, a middle-layer floating island, a lower-layer floating island and a rigid frame; the upper floating island, the middle floating island and the lower floating island are all fixedly arranged in the rigid frame; the upper floating island is positioned on the water surface and used for planting emergent aquatic plants, the middle floating island and the lower floating island are positioned below the water surface, the middle floating island is used for planting submerged plants, and the lower floating island is filled with composite filler;
a plurality of artificial floating islands are fixedly arranged in the lake;
The movable ultrafiltration membrane device comprises a water inlet pipe, a pipeline filter, an immersed ultrafiltration membrane component, a membrane box, a self-priming pump and a clean water tank; one end of the water inlet pipe is communicated with a submersible pump, the submersible pump is arranged in the lake, and the other end of the water inlet pipe is communicated with the pipeline filter; the pipeline filter is communicated with the membrane box through a pipeline, and a plurality of immersed ultrafiltration membrane components are arranged in the membrane box; the water outlet of the membrane tank is communicated with a self-sucking pump through a pipeline, and the self-sucking pump is communicated with the clear water tank through a pipeline and used for storing the treated lake water; the clear water tank is communicated with the lake through a drain pipe and is used for discharging water in the clear water tank into the lake, and the lake water is continuously extracted, treated and then discharged into the lake, so that the circulation and purification of the lake water are realized.
The utility model discloses the method has following characteristics and beneficial effect:
The utility model adopts the artificial ecological floating island system to purify the lake water, can absorb nitrogen and phosphorus elements in the water, reduce the COD value in the water and effectively improve the water quality; the plants are in direct contact with the water body, so that the illumination area of the water surface is reduced, the growth of algae in the water is inhibited, and the water quality purification capacity is improved; beautifies water landscape, purifies surrounding air, increases urban greening, provides places for the living and the reproduction of aquatic animals and birds, has no secondary pollution to a floating island system, and has simple process, convenient operation, low consumption and high economic benefit. Under the condition that the lake water quality is suddenly deteriorated due to winter, rainfall or other conditions, the movable ultrafiltration membrane device is used as an emergency treatment device to purify lake water, and multiple functions of activated carbon adsorption, aeration and oxygenation, microbial biochemical degradation, coagulation and phosphorus removal, nitrification and denitrification, membrane separation and the like are integrated in a membrane box, so that the removal effect on COD (chemical oxygen demand), ammonia nitrogen, total phosphorus, total nitrogen, chromaticity, turbidity and the like is remarkable. The movable ultrafiltration membrane device can be flexibly moved according to the needs of users and is not limited by sites; the device has the advantages of compact internal structure, simple process, strong incoming water impact resistance, stable effluent quality and high automation degree. The utility model can be applied to the purification treatment of most small lakes throughout the country, and has wide application range.
FIG. 1: the system structure chart of the embodiment of the utility model;
In the figure, 1, a movable ultrafiltration membrane device, 2, an artificial floating island, 3, a submersible pump, 4, a water inlet pipe, 5, a water outlet pipe, 6, an upper floating island, 7, a middle floating island, 8, a lower floating island, 9, a rigid frame, 10, emergent aquatic plants, 11, submerged plants, 12, composite fillers, 13, a fan, 14, a pipeline filter, 15, an immersed ultrafiltration membrane component, 16, a membrane box, 17, a membrane pool fan, 18, an aeration disc, 19, a self-sucking pump, 20, a clear water tank, 21, a plant cultivation base disc, 22, a backwashing pump, 23, a sludge pump, 24 and a sludge dewatering device are arranged.
To facilitate understanding and practice of the invention for those skilled in the art, the following detailed description of the invention is provided in conjunction with the accompanying drawings, and it is to be understood that the embodiments described herein are provided for illustration and explanation and are not intended to limit the invention.
Referring to fig. 1, the system for advanced wastewater treatment and concentrated water treatment provided by the utility model comprises an artificial floating island 2;
And/or a movable ultrafiltration membrane device 1, an artificial floating island 2, a submersible pump 3, a water inlet pipe 4 and a water outlet pipe 5;
A plurality of artificial floating islands 2 are fixedly arranged in the lake; the artificial floating island 2 is of a three-layer structure and comprises an upper floating island 6, a middle floating island 7, a lower floating island 8 and a rigid frame 9, wherein the upper floating island 6 is positioned on the water surface, emergent aquatic plants 10 are planted in the rigid frame 9, the middle floating island 7 and the lower floating island 8 are positioned below the water surface, the middle floating island 7 is 0.5-2.0 meters away from the water surface, submerged plants 11 are planted in the rigid frame 9, the lower floating island 8 is 2.5-3.5 meters away from the water surface, composite fillers 12 are installed in the rigid frame 9, a fan 13 is adopted for aeration and oxygenation, and the absorption of plant roots to nitrogen and phosphorus nutrients is promoted.
Meanwhile, a set of movable ultrafiltration membrane device 1 is arranged beside a lake and used as an emergency treatment device for sudden deterioration of lake water quality caused by winter, rainfall or other conditions, the submersible pump 3 is fixedly arranged 2.0-3.0 meters below the lake liquid level, one end of the water inlet pipe 4 is connected with the submersible pump 3, the other end of the water inlet pipe is connected with a water inlet of the movable ultrafiltration membrane device 1, the movable ultrafiltration membrane device 1 comprises a pipeline filter 14, an immersed ultrafiltration membrane assembly 15, a membrane box 16, a membrane pool fan 17, an aeration disc 18, a self-sucking pump 19 and a clear water tank 20, lake water is sucked by the submersible pump 3, large-particle impurities are filtered by the pipeline filter 14, activated sludge is put in the membrane box 16, nitrobacteria powder and denitrifying bacteria powder with certain concentration are added for long-term acclimation culture, a coagulant PAC and powdered activated carbon are added for treatment, oxygen is supplied to the membrane box 16 by the membrane pool fan 17, so as, the treated lake water is extracted from the membrane box 16 by the self-sucking pump 19 and stored in the clear water box 20 and is discharged into the lake through the water discharge pipe 5, and the lake water is continuously extracted, treated and discharged into the lake, so that the circulation and purification of the lake water are realized.
The rigid frame 9 of this embodiment is made of fiber reinforced plastic, special synthetic resin, and concrete material.
In the embodiment, the rigid frames 9 in the upper floating island 6 and the middle floating island 7 are also provided with plant cultivation base plates 21, and the plant cultivation base plates 21 are formed by mixing coconut fibers, fish nets and soil and are used for planting aquatic plants.
The compound 12 of packing of this embodiment is the biological baseband, mainly comprises weaving layer and foam layer, and the weaving layer can set up fibrous density degree according to actual need, makes its surface form the symbiotic microorganism system of phycomycetes, and the foam layer is located in the middle of two-layer weaving layer, makes it closely laminate with the weaving layer together through special processing, makes the biological baseband keep the state of floating in rivers.
the submerged ultrafiltration membrane assembly 15 has a hollow fiber structure, is made of PVDF (polyvinylidene fluoride), has the operating pressure of 0.05-0.1 MPa, the average pore diameter of the membrane surface is less than or equal to 0.05 mu m, the membrane diameter is 0.8-1.9 mm, and the membrane water production flux is 10-15L/(. square meter.h). The submerged ultrafiltration membrane module 15 requires periodic backwashing, and the backwashing water is derived from the clean water tank 20.
The movable ultrafiltration membrane device 1 of the embodiment is of an integrated container type structure, can be flexibly moved according to the needs of users and is not limited by sites. The movable ultrafiltration membrane device 1 is also provided with a backwashing pump 22, one end of the backwashing pump 22 is connected with the immersed ultrafiltration membrane component 15, and the other end is connected with the clean water tank 20. The movable ultrafiltration membrane device 1 is also provided with a sludge pump 23 and a sludge dewatering device 24 for dewatering the sludge generated by the movable ultrafiltration membrane device 1.
The system of the embodiment can realize PLC full-automatic control.
the utility model discloses a method that "artificial ecological chinampa + portable milipore filter device" combined together carries out purification treatment to small-size lake water, and technological principle is as follows:
Ecological chinampa mainly reaches the effect of purifying water through the root system of benthophyte, and the root system of chinampa plant can absorb and adsorb the nitrogenous, phosphorus material in aquatic on the one hand, and on the other hand the root system can secrete a large amount of enzymes to promote the decomposition of aquatic organic matter, and moreover, root system and microorganism can form synergistic effect each other, degrade the nutritive salt of aquatic jointly. Besides the function of root system, the floating island plants occupy a certain area on the water surface, so that the photosynthesis of algae can be weakened, and some floating island plants also have the function of restraining the growth of algae, so that the deterioration of water quality is delayed.
Under the condition that the lake water quality is suddenly deteriorated due to winter, rainfall or other conditions, a movable ultrafiltration membrane device is used as an emergency treatment device to purify lake water, a coagulant PAC is firstly added into a membrane box to destabilize colloids in the water to form smaller flocs and transfer phosphorus elements in the sewage into floc particles so as to reduce the total phosphorus in the water, meanwhile, powdered activated carbon is also added into the membrane box to adsorb and remove pollutants such as chromaticity, COD and the like in the sewage, nitrifying bacteria and denitrifying bacteria with certain concentration are also added into the membrane box, NH 3 -N (NH 4 +) is oxidized into NO 3 - by the nitrification of autotrophic bacteria in an adequate oxygen supply area to form nitrifying liquid, the nitrifying liquid is synchronously denitrified in an anoxic area, the denitrification of the heterotrophic bacteria reduces NO 3 - into molecular nitrogen (N 2), the removal of the total nitrogen and the residual sludge in the membrane box are separated by a total nitrogen removal mode, the sludge is treated by a movable ultrafiltration membrane device, a sludge denitrification membrane module, a sludge water removal mode, a coagulation sedimentation tank, a sludge removal effect, a sludge removal effect.
The utility model discloses a work flow, including following step:
Step 1: in the artificial floating island 2, the fan 13 is started to aerate and oxygenate, so that the absorption of plant roots to nitrogen and phosphorus nutrients is promoted, microorganisms are degraded, and the effects of purifying water quality and improving landscape functions are achieved;
Step 2: under the condition that the lake water quality is suddenly deteriorated due to winter, rainfall or other conditions, the submersible pump 3 and the movable ultrafiltration membrane device 1 are started to be used as an emergency treatment device, the lake water is pumped by the submersible pump 3 and is conveyed into the movable ultrafiltration membrane device 1 through the water inlet pipe 4;
And step 3: the incoming water is filtered to remove large-particle impurities through the pipeline filter 14, then a coagulant PAC and carbon-water mixture is added into the membrane box 16, phosphorus-containing impurities in the sewage are coagulated due to destabilization of colloidal particles, smaller flocs are gradually separated from the water, meanwhile, COD can be further removed through the adsorption effect of the powdered activated carbon, the phosphorus-containing flocs and the powdered activated carbon are intercepted by the immersed ultrafiltration membrane component 15 and are retained in the membrane box 16, and the removal of COD and total phosphorus is realized;
wherein the adding amount of the PAC coagulant is 20-30 mg/L, the carbon-water mixture is prepared by solid powder activated carbon and clear water in the clear water tank 20, and the actual adding amount of the solid powder activated carbon is 10-30 mg/L;
and 4, step 4: meanwhile, activated sludge is put into the membrane box 16, nitrifying bacteria powder and denitrifying bacteria powder with certain concentration are added, long-term domestication culture is carried out, a membrane pool fan 17 is adopted to aerate and supply oxygen to the membrane box 16 through an aeration disc 18 at the bottom, ammonia nitrogen and total nitrogen in sewage are removed under the action of nitrification and denitrification, residual sludge is intercepted by the immersed ultrafiltration membrane component 15, and purified water is discharged out of the membrane box 16.
And 5: the purified water discharged from the immersed ultrafiltration membrane module 15 is sucked by a self-sucking pump 19 and then enters a clean water tank 20, and due to the liquid level difference, the purified water is discharged into the lake through a water discharge pipe 5 in a self-flowing manner, and the circulating purification of the lake water is realized through repeated extraction, treatment and discharge.
Step 6: the immersed ultrafiltration membrane module 15 is backwashed regularly every day, and residual sludge and waste carbon slurry in the membrane box 16 are conveyed to a sludge dewatering device 24 through a sludge pump 23 for dewatering and then are transported to outside for disposal.
It should be understood that parts of the specification not set forth in detail are well within the prior art.
It should be understood that the above description of the preferred embodiments is given in some detail, and not as a limitation to the scope of the invention, and that various alternatives and modifications can be devised by those skilled in the art without departing from the scope of the invention as defined by the appended claims.