Ecological filter for preventing and controlling river pollution and method for preventing and controlling river pollution

Abstract

The present invention provides an ecological filter for preventing and controlling river pollution and a method for preventing and controlling river pollution. The ecological filter is located in a river and is constructed by relying on a river bank. The ecological filter isolates river water by a sealed tank body (100). A support structure is arranged below the ecological filter at a set height from the bottom of the ecological filter. A modular filler layer is supported above the support structure to treat sewage along the river introduced into the ecological filter. The space below the support structure is not filled with fillers. The present invention constructs an ecological filter in a river and relies on a river bank, adopts modularized diversified fillers and a dynamic circulation purification method, and can effectively treat sewage along the river that will enter the river, thereby playing a role in regulating the quality of the river water environment.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to an ecological filter tank for preventing and controlling river pollution and a method for preventing and controlling river pollution. Background Art

[0002] Under the favorable environment of rapid social and economic development and steady and steady progress of urbanization in China, the water environment in urban areas is deteriorating. Untreated production wastewater from some enterprises and domestic sewage from some coastal residents are directly or indirectly discharged into nearby rivers, which changes the water quality of rivers and causes serious water pollution in rivers flowing through urban areas. Some rivers even become black and smelly, which seriously affects the construction of urban ecological civilization and the daily life of coastal residents, and also restricts the sustainable and healthy development of social economy. Therefore, it is a problem worthy of attention to comprehensively treat polluted rivers in cities and restore their surrounding ecosystems.

[0003] The sources of pollution in urban rivers are divided into urban domestic sewage, industrial wastewater and agricultural non-point source pollution: (1) Urban domestic sewage. Due to the imperfect drainage system in some cities and towns, some domestic sewage, especially the daily sewage of coastal residents, is directly discharged into the river, causing river water pollution; (2) Industrial wastewater. Factories built around rivers discharge production wastewater into rivers. Industrial wastewater contains a large amount of toxic and harmful substances, causing serious pollution to water bodies; (3) Agricultural non-point source pollution. Mainly due to the large-scale use of fertilizers and pesticides, these toxic substances enter the river with the surface runoff formed by rainfall. Among them, urban domestic sewage and agricultural non-point source pollution wastewater are uncontrollable wastewaters and are not easy to be effectively controlled through government intervention.

[0004] Treating domestic sewage and agricultural non-point source pollution wastewater before discharging it into the river can prevent and control river pollution, which is a more feasible and effective way than treating river water after it is polluted. Therefore, studying the engineering system for maintaining river water quality is the key to improving the quality of urban water environment. Summary of the invention

[0005] In order to overcome the above-mentioned defects, the inventors have conducted intensive research and provided an ecological filter tank for preventing and controlling river pollution and a method for preventing and controlling river pollution. By constructing an ecological filter tank in the river and relying on the river bank, and adopting modular diverse fillers and dynamic circulation purification methods, it is possible to effectively treat the coastal sewage that will enter the river, and play a regulatory role in the water environment quality of the river, thereby completing the present invention.

[0006] The object of the present invention is to provide the following technical solutions:

[0007] (1) An ecological filter for preventing and controlling river pollution, the ecological filter being located in the river and constructed against the river bank,

[0008] The ecological filter tank isolates the river water by sealing the tank body 100, and a support structure is arranged below the ecological filter tank at a set height from the bottom thereof, and a modular filler layer is supported above the support structure to treat the sewage along the river introduced into the ecological filter tank, and the space below the support structure is not filled with fillers;

[0009] The modular packing layer is arranged in three layers from bottom to top, which are the mineral particle layer 210 at the bottom, the bioreactor layer 220 at the middle, and the ecological layer 230 at the top.

[0010] The mineral particle layer 210, whose filler is natural mineral particles or treated natural mineral particles, is used for filtering sewage along the river, absorbing pollutants and biodegrading;

[0011] The bioreactor layer 220, whose filler is suspended small balls for carrying biofilm, utilizes biofilm to reduce pollutants in sewage along the river bank;

[0012] The ecological layer 230 is filled with fillers capable of supporting the growth of aquatic plants;

[0013] The river sewage entering the biofilter is input into the mineral particle layer 210 through the water inlet pipe 240, and then enters the bioreactor layer 220 and the ecological layer 230 from bottom to top.

[0014] (2) A method for preventing and controlling river pollution, preferably using the ecological filter described in (1) above to prevent and control river pollution.

[0015] An ecological filter tank for preventing and controlling river pollution and a method for preventing and controlling river pollution provided by the present invention have the following beneficial effects:

[0016] (1) In the present invention, a modular filler layer is used in the ecological filter, including a mineral particle layer, a bioreactor layer located in the middle, and an ecological layer located in the upper layer. The fillers are zeolite-limestone, microporous hollow balls filled with polyurethane sponge, and ceramsite crushed particles. The three layers of fillers have their own specialties and have a synergistic treatment effect on sewage.

[0017] (2) In the present invention, there is a space without filler between the support structure and the bottom of the ecological filter, which can accommodate particulate impurities in the sewage along the river entering the ecological filter and particulate impurities that fall off after being trapped in the mineral particle layer, thereby providing a prerequisite for the self-cleaning of the ecological filter.

[0018] (3) In the present invention, a fixed multi-layer filter screen is arranged in the area from the support structure to the bottom of the ecological filter tank, and the mesh size of the filter screen gradually decreases from top to bottom. This arrangement plays a limiting role, allowing particles to enter the bottom of the filter tank relatively easily. However, particles deposited at the bottom of the filter tank are difficult to rise to the mineral particle layer.

[0019] (4) In the present invention, the filler in the mineral particle layer is filled in a metal wire cage, and the bioreactor layer and the ecological layer are filled in a box with through holes distributed at the bottom. The containers (i.e., the box) of the bioreactor layer and the ecological layer can ensure dynamic decontamination.

[0020] (5) In the present invention, during biofilm domestication, waste mash from the alcohol workshop of a sugarcane factory is pumped into the ecological filter, which is beneficial to biofilm domestication and provides a treatment pathway for the waste mash. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A side cross-sectional view of an eco-filter tank according to a preferred embodiment of the present invention is shown;

[0022] Figure 2 A top view of an ecological filter tank according to a preferred embodiment of the present invention is shown.

[0023] Description of Figure Numbers:

[0024] 100-Pool body;

[0025] 210-mineral granular layer;

[0026] 220 - bioreactor layer;

[0027] 230-Ecological layer;

[0028] 240-water inlet pipe;

[0029] 250-wire mesh;

[0030] 260-filter;

[0031] 310-water return channel I;

[0032] 320-water return channel II;

[0033] 400-Inspection well;

[0034] 510- aeration pipe;

[0035] 520 - Aeration pump. DETAILED DESCRIPTION

[0036] The present invention is described in detail below through specific implementation modes, and the characteristics and advantages of the present invention will become clearer and more specific with these descriptions.

[0037] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0038] like Figure 1 and Figure 2 As shown, the purpose of the present invention is to provide an ecological filter for preventing and controlling river pollution. The ecological filter is located in the river and is constructed by relying on the river bank. The ecological filter isolates the river water by sealing the tank body 100. A support structure is arranged below the ecological filter at a set height from the bottom of the ecological filter. The modular filler layer is supported above the support structure to treat the sewage along the river introduced into the ecological filter. The treated sewage can be discharged into the river or transported to other places for use.

[0039] The modular packing layer is arranged in three layers from bottom to top, which are a mineral particle layer 210 at the bottom, a bioreactor layer 220 at the middle, and an ecological layer 230 at the top.

[0040] The mineral particle layer 210, the filler is natural mineral particles or processed (such as calcined) natural mineral particles, such as one or more of gravel, natural zeolite, volcanic stone, calcite, limestone, and pebbles, which are used to filter sewage along the river, adsorb pollutants and biodegrade;

[0041] The bioreactor layer 220, whose filler is suspended small balls for carrying biofilm, utilizes biofilm to reduce pollutants in sewage along the river bank;

[0042] The ecological layer 230 is filled with fillers that can support the growth of aquatic plants, and uses the synergistic effect of plant roots, microorganisms, and fillers to reduce pollutants in sewage along the river;

[0043] The river sewage entering the biofilter is input into the mineral particle layer 210 through the water inlet pipe 240, and enters the bioreactor layer 220 and the ecological layer 230 from bottom to top in sequence, and the sewage is purified in a vertical undercurrent mode.

[0044] In the present invention, a plurality of ecological filter tanks can be arranged along the river bank to form an ecological filter tank group separated by a set interval.

[0045] In the present invention, the pool body 100 of the ecological filter is a closed structure made of concrete or glass that can isolate river water. The river bank can serve as one surface of the pool body 100 or the pool body 100 is an independent structure independent of the river bank.

[0046] The supporting structure arranged below the ecological filter tank includes a plurality of bars connecting two arbitrary sides of the tank body 100, and preferably a metal wire mesh 250 is laid on the bars. The bars and the preferably metal wire mesh 250 can stably support the modular filler layer.

[0047] In the present invention, as described above, there is a space without fillers from the support structure to the bottom of the ecological filter, which can accommodate particulate impurities in the sewage along the river bank entering the ecological filter and particulate impurities that fall off after being intercepted in the mineral particle layer 210. Compared with ecological filters or biological wetlands without bottom space, the bottom filler layer (mineral particle layer 210) that plays the main physical filtration role in the present invention has self-cleaning ability due to the hydraulic flow and the solid particle accommodation space below it, and is not easy to cause filler blockage. The service life of the bottom filler is extended, the purification function of the ecological filter is improved, and the difficulty of later maintenance is improved.

[0048] Furthermore, two to three layers of filter screens 260 are fixed in the area from the support structure to the bottom of the ecological filter tank, and the mesh size of the filter screens 260 gradually decreases from top to bottom. In this way, the fallen particles can relatively easily enter the bottom of the filter tank, but the particles deposited at the bottom of the filter tank are difficult to rise to the mineral particle layer 210.

[0049] In a preferred embodiment of the present invention, the mineral particle layer 210 is composed of limestone and zeolite, and the mixing ratio is 1: (2-6), preferably 1: (3-4); the filler particle size is 5-30 mm, preferably 10-20 mm; the thickness of the mineral particle layer 210 is 30-60 cm, preferably 40-50 cm.

[0050] In the present invention, the limestone plays a filtering and adsorption role on the one hand, which is based on the porous structure of the limestone; on the other hand, it can adjust the pH value of the purification system, facilitate the reproduction of microorganisms and provide an inorganic carbon source, which is based on the chemical composition of the limestone, CaCO3. When the pH value of the sewage entering the ecological filter is low, the limestone surface decomposes, neutralizes the acidic substances and produces an inorganic carbon source that is conducive to the reproduction of autotrophic microorganisms (such as nitrite bacteria (AOB) and AnAOB (anaerobic ammonia oxidizing bacteria)); and the CaCO3 produced at the same time 2+ It can react with phosphate in sewage to produce precipitation (see Formulas 1 and 2 below), enriching the removal pathways of phosphorus.

[0051] Ca 2+ +HPO4 2- +2H2O=CaHPO4·2H2O(precipitate) Formula (1)

[0052] 2CaHPO4·2H2O+ Ca 2+ =Ca3(PO4)2(precipitate)+2H + +2H2O Formula (2)

[0053] Zeolite is used as the main adsorption filler and supporting filler of the mineral particle layer 210, which is based on its porous structure, large specific surface area, extremely high adsorption performance and filtration performance.

[0054] The selection of filler particle size in the present invention takes into account the size of the voids generated by the packing accumulation and the effect on the obstruction of sewage flow in the packing layer. When the filler particle size is less than 5 mm, although the adsorption strength is improved, the packing density of the filler is too large, the voids between the fillers are small and the sewage flow is obstructed, and the particles are easily blocked and difficult to separate from the filler; when the filler particle size is greater than 30 mm, the packing density of the filler is small, although the particles are not easy to be blocked and easy to separate from the filler, the filtration capacity and adsorption capacity are limited.

[0055] Combined with a filler height of 30 to 60 cm, preferably 40 to 50 cm, and a filler particle size of 5 to 30 mm, preferably 10 to 20 mm, effective filtration and primary adsorption efficiency can be achieved.

[0056] In the present invention, the filler in the mineral particle layer 210 is filled in a metal wire cage, and the metal wire cage has multiple meshes, so that the particle impurities can be easily separated.

[0057] In a preferred embodiment of the present invention, the filler of the bioreactor layer 220, i.e., the suspended small balls used to carry the biofilm, are microporous hollow balls filled with polyurethane sponge. The material of the microporous hollow balls is a polymer material such as high-density polyethylene, polyurethane, etc.; the diameter and number of meshes of the microporous hollow balls can be conventional in the art. Preferably, the diameter of the microporous hollow balls is 10 to 20 mm, and the mesh of the microporous hollow balls is 40 to 100 meshes. It is understandable that the carrier of the filler of the bioreactor layer 220 is not limited to the above-mentioned microporous hollow balls. The above-mentioned microporous hollow balls are the preferred method, and other materials, specifications and structures can also be selected to meet the requirements of being able to carry the above-mentioned filler and suspend in sewage.

[0058] In the present invention, polyurethane sponge is used as a carrier for biofilm formation. Polyurethane sponge is a porous material with a large surface area, good water absorption and hydrophilicity. It swells and absorbs water in water, and absorbs microorganisms in the water into the internal pores of the sponge. Biofilm can be formed in the internal pores and on the surface, thereby adsorbing or degrading pollutants such as organic matter, nitrogen and phosphorus, and heavy metals in sewage.

[0059] In the present invention, the height of the bioreactor layer 220 is 30 cm to 60 cm, the filling height of the microporous hollow balls is 1 / 2 to 2 / 3 of the height of the bioreactor layer 220, and the filling ratio of the polyurethane sponge in the microporous hollow balls is 60% to 80%. If the density of the microporous hollow balls is too low to allow the microporous hollow balls to be in a suspended state, a weighting agent may be added to the microporous hollow balls to allow the microporous hollow balls to be suspended in sewage, and the weighting agent may be a mineral material such as sand and gravel.

[0060] The filling height of the microporous hollow balls accounts for 1 / 2 to 2 / 3 of the height of the bioreactor layer 220. There is space for the microporous hollow balls to move freely in the layer. The movement of the microporous hollow balls disturbs the sewage in the layer, which is beneficial to the full contact between the filler and the pollutants. It is easy to understand that the purification efficiency of disturbed sewage purification is improved compared with static sewage purification.

[0061] The filling height of the microporous hollow balls combined with the filling ratio of the polyurethane sponge determines the amount of biofilm formed in the bioreactor layer 220. When the filling height of the microporous hollow balls is 1 / 2 to 2 / 3 of the height of the bioreactor layer 220 and the filling ratio of the polyurethane sponge in the microporous hollow balls is 60% to 80%, combined with the performance of the mineral particle layer 210 and the ecological layer 230, efficient treatment of sewage can be achieved.

[0062] In the present invention, the filler of the bioreactor layer 220 is filled in a box with through holes distributed at the bottom and an opening at the top. After the sewage is treated by the mineral particle layer 210, it enters the bioreactor layer 220 through the through holes at the bottom of the open box; the top of the open box is connected to the bottom of the container of the ecological layer 230.

[0063] In the present invention, the filler of the ecological layer 230 is ceramsite crushed particles, the filling height of the filler is 40 to 50 cm, and the particle size of the ceramsite crushed particles is 5 to 10 mm.

[0064] Expanded clay is a lightweight spherical particle with a smooth and hard surface and fine honeycomb-like micropores in its internal structure. The crushed expanded clay particles expose the micropore structure, increasing the specific surface area, and are capable of filtering sewage and degrading pollutants after biofilm formation.

[0065] The choice of filler filling height is based on the extension space of aquatic plant roots and the effectiveness of sewage treatment; if the filler filling height is lower than 40cm and the particle size is greater than 10mm, the plant roots are unstable, which is not conducive to plant planting, and the sewage filtration effect is low; if the filler filling height is higher than 40cm or even 50cm and the particle size is less than 5mm, although the plant roots are stable and the water purification effect is improved, the hydraulic rise resistance is large and the water discharge is slow.

[0066] In the present invention, the ceramsite crushed particles can be obtained by crushing commercially available ceramsite, or by a method comprising the following steps:

[0067] Step 1, drying and grinding the biological sludge and clay, adding a soluble iron salt aqueous solution to granulate, and sintering at 700-800° C. to obtain ceramsite;

[0068] Step 2, crushing the ceramsite, adding sodium borohydride solution to reduce the iron ions to a low valence state;

[0069] Step 3, washing the reduced ceramsite crushed particles with distilled water and drying them, so as to obtain the ceramsite crushed particles for the ecological layer 230.

[0070] In step 1, the soluble iron salt aqueous solution may be an aqueous solution of ferric chloride, ferrous chloride, ferric nitrate, ferric sulfate, or the like.

[0071] After adding the soluble iron salt aqueous solution, the biological sludge and clay should have a smooth surface, can be held in a ball by hand and have no excess water overflowing.

[0072] The mass ratio of biological sludge, clay and soluble iron salt is (0.1-0.4):1:(0.02-0.05). Biological sludge is taken from the biological sludge produced after sewage treatment plant treats sewage. Direct discharge or incineration of biological sludge will cause secondary ecological environmental pollution. Using it as a raw material for ceramsite and replacing part of the clay with biological sludge to burn ceramsite not only saves clay but also plays a certain role in environmental protection. The ratio of biological sludge to clay is based on the consideration of the firing and forming of ceramsite. If the amount of biological sludge added is greater than 0.4 parts, the ceramsite is more likely to disintegrate into small particles during the firing process and cannot be used.

[0073] After soluble iron salts are added to biological sludge and clay, during the sintering process, iron ions are melted and gathered into balls, forming iron crystals distributed on the honeycomb inner wall of ceramsite. When the ceramsite is crushed and reduced, crushed ceramsite particles loaded with nano zero-valent iron are formed. Nano zero-valent iron can reduce and remove organic pollutants that are difficult to degrade, such as halogenated hydrocarbons, and convert them into non-toxic or low-toxic compounds, while improving its biodegradability. It can also effectively remove heavy metal ions through reduction or complexation. However, nano zero-valent iron that does not exist in a loaded form has a small particle size, high surface energy, and magnetism. If used directly, it will be too costly for sewage treatment, and the effect will be greatly reduced. The present invention forms nano zero-valent iron in situ in ceramsite, and it will not aggregate or lose when used for sewage treatment. After the pollutants are adsorbed on the surface of the ceramsite, the nano zero-valent iron cooperates with microbial activities to remove pollutants together.

[0074] In step 2, the concentration of the sodium borohydride solution is between 0.75 mg / L and 1.5 mmol / L. Step 2 is performed under an inert atmosphere.

[0075] In the present invention, the aquatic plants planted on the ecological layer 230 include but are not limited to wild rice stem, lotus, alfalfa, cattail, ryegrass, orchard grass, vetiver and the like.

[0076] In the present invention, the filler of the ecological layer 230 is filled in an open box with through holes at the bottom. After the sewage is treated by the bioreactor layer 220, it enters the ecological layer 230 through the through holes at the bottom of the box. The height of the open box is higher than the height of the filler filled therein, and a filter is fixed on the surface of the filler to position the filler below it, so that the filler and the upper effluent form a clear cross section.

[0077] Ecological wetlands or ecological filter tanks are generally static decontamination. In order to effectively purify sewage therein, a longer residence time is required, and the decontamination efficiency needs to be improved. To this end, the inventors set a water circulation channel to construct a dynamic decontamination system.

[0078] The water circulation channel includes a return water channel I 310 connecting the open box of the ecological layer 230 and the open box of the bioreactor layer 220, a return water channel II 320 connecting the open box of the ecological layer 230 and the metal wire cage of the mineral particle layer 210, and a water pump that will provide power for water circulation;

[0079] The water pump extracts the water from the upper part of the packing of the ecological layer 230 and transports it to the side bottom of the open box of the bioreactor layer 220 through the return water channel I 310;

[0080] The water pump extracts the water from the upper part of the filler of the ecological layer 230 and transports it to the filler of the mineral particle layer 210 through the return water channel II 320.

[0081] The fillers in the bioreactor layer 220 do not fill the box and are in a suspended state. Return water, especially pressurized return water, rushes in from the side and bottom, disturbing the fillers and promoting the purification function of the fillers.

[0082] The return water channel II 320 transports the return water to the bottom filler of the mineral particle layer 210. The return water has a lower amount of sewage particles than the initial sewage particles entering the biofilter, which has an impact on the particles adsorbed or filtered in the mineral particle layer 210. The particles can be separated from the mineral particle layer 210 and settle to the bottom of the biofilter through the mesh of the wire cage.

[0083] Preferably, the return water channel I 310 and the return water channel II 320 are both water pipes with a small diameter, preferably with a diameter of 1.6 to 3.0 cm. In this way, the return water transported by the return water channel I 310 enters the closed box of the bioreactor layer 220 with a large impact force, causing effective disturbance of the filler, and the return water transported by the return water channel II 320 enters the mineral particle layer 210 with a large impact force, causing impact on the particle impurities in the filler, which is conducive to the separation of the particles.

[0084] More preferably, the portion of the return water channel II 320 extending into the mineral particle layer 210 passes through the wire cage, and the tube wall is densely covered with through holes, thereby increasing the impact surface on the filler.

[0085] In the present invention, an inspection well 400 is constructed on the side of the pool body 100 against the river bank, and a suction pipe is arranged in the well, which can penetrate into the ecological filter tank, enter the support structure to the bottom of the ecological filter tank. After the ecological filter tank runs for a certain period of time, the purification work is stopped, and the sediment at the bottom of the ecological filter tank is pumped out by turning on the pump that provides suction power for the suction pipe.

[0086] In the present invention, the ecological filter also includes an aeration system, which includes an aeration pipe 510 and an aeration pump 520. The aeration pipe 510 extends into the mineral particle layer 210, and oxygen-containing gas is introduced into the ecological filter through the aeration pipe 510 driven by the aeration pump 520. Preferably, the aeration system ensures that the oxygen content in the ecological filter is between 1.4 and 2.0 mg / L. Under this oxygen content, coupled with the stacking of filler particles, an aerobic-anoxic-anaerobic environment exists in the ecological filter, which is conducive to the diversity of microorganisms.

[0087] After the ecological filter is constructed, before it is put into use, the ecological filter, especially the bioreactor layer 220, needs to be domesticated and biofilmed. The microorganisms used for domestication and biofilming include nitrite bacteria (AOB), nitrifying bacteria (NOB), and AnAOB (anaerobic ammonium oxidizing bacteria), and may also include polyphosphate bacteria.

[0088] In a preferred embodiment, during the biofilm acclimation, waste mash from the alcohol workshop of a sugarcane factory is pumped into the ecological filter. The waste mash from the alcohol workshop is a high-concentration acidic organic wastewater with a BOD5:COD cr>0.45, good biodegradability, easy to be treated by ecological filter. The waste mash is added to the ecological filter. First, considering that the growth rate of microorganisms (especially autotrophic bacteria such as nitrite bacteria and anaerobic ammonia oxidizing bacteria) is slow, the period of forming biofilm on the filler is relatively long, and the waste mash contains a high content of organic matter, which is conducive to overcoming the inhibition of electrostatic force on the surface of the filler, and can act as a "temporary biofilm" to make microorganisms condense and adhere to the surface of the filler, and promote microbial condensation until a stable biofilm is formed; second, sewage contains heterotrophic microorganisms, and the addition of waste mash provides nutrients for the reproduction of heterotrophic microorganisms; third, the waste mash is acidic, even if it is added to the ecological filter, there is a mineral particle layer 210 to neutralize it, not only will it not affect the function of the biological filter, but the CO2 produced by the acidification and decomposition of the limestone surface is beneficial to the reproduction of autotrophic microorganisms as an inorganic carbon source; fourth, the waste mash itself is a waste liquid to be treated, and this method provides a treatment route for it. The addition of waste mash, with the initial sewage COD in the ecological filter cr The content should be between 250 and 1000 mg / L.

[0089] During the operation of the ecological filter, waste mash from the alcohol workshop of the sugarcane factory can still be pumped into the ecological filter. At this time, the addition of waste mash is mainly used as a carbon source for heterotrophic microorganisms.

[0090] Another object of the present invention is to provide a method for preventing and controlling river pollution, preferably using the above-mentioned ecological filter to prevent and control river pollution.

[0091] That is, the method includes constructing an ecological filter tank located in a river channel and relying on the river bank. The ecological filter tank isolates the river water by sealing the tank body 100. A support structure is arranged below the ecological filter tank at a set height from the bottom of the ecological filter tank. A modular filler layer is supported above the support structure to treat the sewage along the river channel introduced into the ecological filter tank. The treated sewage can be discharged into the river channel or transported to other places for use.

[0092] Example

[0093] Example 1

[0094] In the laboratory, an artificial ecological filter was simulated. The height of the ecological filter was 2.2m, and the length and width were both 1.5m. The length and width of the modular filler layer were both 1.0m. The ecological filter included a concrete tank body, and a metal bracket was set at a height of 20cm below the bottom of the tank body. A metal wire mesh was laid on the metal bracket to support the modular filler layer.

[0095] The mineral particle layer 210 of the bottom layer is composed of limestone and zeolite, with a mixing ratio of 1:2, a filler particle size of 5 to 30 mm, and a layer height of 30 cm; the filler is placed in a wire cage; the filler of the bioreactor layer 220 in the middle is a microporous hollow ball filled with polyurethane sponge, the diameter of the microporous hollow ball is 10 mm, the mesh is 40 mesh, the layer height is 60 cm, and the filling height of the microporous hollow ball is 1 / 2 of the height of the bioreactor layer 220; the polyurethane sponge is placed in the microporous hollow ball. The filling ratio is 60%, and the microporous hollow balls are installed in a polyurethane box with through holes at the bottom and an opening at the top; the filler of the ecological layer 230 located at the upper layer is the crushed particles of ordinary clay ceramsite (crushed ceramsite particles), the filling height of the filler is 40cm, and the particle size of the crushed ceramsite particles is 5-10mm; this layer of filler is filled in a polyurethane open box with through holes at the bottom, and a metal filter is fixed on the surface of the filler to position the filler below, so that the filler and the upper water outlet form a clear cross section. The cross-sectional areas of the metal wire cage and the two polyurethane open boxes are consistent, and stable stacking can be carried out. PVC pipes with a diameter of 1.6cm are set between the ecological layer 230 and the bioreactor layer 220, and between the ecological layer 230 and the bottom of the mineral particle layer 210, respectively, and dynamic water circulation can be achieved under the drive of the pump.

[0096] The water inlet pipe 240 is extended into the bottom of the mineral particle layer 210, and the sewage can enter the bioreactor layer 220 and the ecological layer 230 from bottom to top in turn, and the sewage is purified in a vertical submerged flow mode. The aeration pipe 510 is extended into the mineral particle layer 210, and oxygen-containing gas can be introduced into the ecological filter tank through the aeration pipe 510 driven by the aeration pump 520. During sewage treatment, the aeration system can ensure that the oxygen content in the ecological filter tank is between 1.4 and 2.0 mg / L.

[0097] After the ecological filter is constructed, artificially prepared sewage is introduced into it, and nitrite-reducing bacteria, nitrifying bacteria, anaerobic ammonia-oxidizing bacteria and polyphosphate-accumulating bacteria are inoculated. The cycle is started for microbial domestication, so that the microorganisms attach and grow on the biofilter filler. The domestication time is 5 days. cr The total concentration is 500 mg / L (prepared with anhydrous sodium acetate), the total nitrogen is 100 mg / L (prepared with ammonium chloride), and the total phosphorus is 5 mg / L (prepared with potassium dihydrogen phosphate).

[0098] After the acclimation, the artificially prepared sewage was pumped in again. The COD cr 400mg / L (prepared with anhydrous sodium acetate), total nitrogen 46mg / L (prepared with ammonium chloride), total phosphorus 5.0mg / L (prepared with potassium dihydrogen phosphate), Pb 2+ 0.05 mg / L (prepared with lead nitrate), Zn 2+The concentration is 2.0 mg / L (prepared with zinc nitrate), the pH is 6.8-7.3, the hydraulic retention time is controlled at 12 hours, the temperature is 30°C, the water circulation is turned on, water samples are taken every 12 hours, and the water quality indicators are measured.

[0099] Example 2 (Increased decontamination effect)

[0100] The structure of the ecological filter is consistent with that of Example 1, except that in the mineral particle layer 210, the mixing ratio of limestone and zeolite is 1:6, and the height of the layer is 60 cm.

[0101] Example 3 (equivalent)

[0102] The structure of the ecological filter is consistent with that of Example 1, except that the height of the bioreactor layer 220 is 30 cm, the filling height of the microporous hollow balls is 2 / 3 of the height of the bioreactor layer 220, and the filling ratio of the polyurethane sponge in the microporous hollow balls is 80%.

[0103] Example 4 (Increased decontamination effect)

[0104] The structure of the ecological filter is consistent with that of Example 1, except that the ceramsite crushed particles are obtained by the following steps:

[0105] The biological sludge and clay are dried and ground, and then granulated by adding a soluble iron salt aqueous solution, wherein the mass ratio of the biological sludge, clay and soluble iron salt is 0.2:1:0.05-0.05, and sintered at 700-800°C to obtain ceramsite;

[0106] The ceramsite was crushed, and 1.0 mmol / L sodium borohydride solution was added at low temperature to reduce the iron ions to a low valence state, and nitrogen was slowly introduced into the solution during the reaction;

[0107] The crushed ceramsite particles after reduction are washed with distilled water and dried to obtain the crushed ceramsite particles for the ecological layer 230 .

[0108] Example 5 (reduced decontamination effect)

[0109] The structure of the ecological filter is consistent with that of Example 1, except that the containers of the bioreactor layer 220 and the ecological layer 230 are replaced with wire cages, and the water circulation operation is stopped during the water purification process.

[0110] Example 6 (reduced decontamination effect)

[0111] The structure of the ecological filter is consistent with that of Example 1, except that in the mineral particle layer 210, the mixing ratio of limestone and zeolite is 1:1, and the height of the layer is 30 cm.

[0112] Example 7 (Decontamination Effect Reduced)

[0113] The structure of the ecological filter is consistent with that of Example 1, except that the microporous hollow balls of the filler of the bioreactor layer 220 do not contain polyurethane sponges.

[0114] Example 8 (reduced decontamination effect)

[0115] The structure of the ecological filter is consistent with that of Example 1, except that the filler of the bioreactor layer 220 is zeolite, the zeolite particle size is 5 to 30 mm, and the filling height is 30 cm.

[0116] The treated water samples were taken for water quality testing and the results are shown in Table 1 below.

[0117] Table 1

[0118]

[0119]

[0120] The present invention is described in detail above in conjunction with specific embodiments and / or exemplary examples and drawings, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. An ecological filter for preventing and controlling river pollution, characterized in that: The ecological filter is located in the river and is built on the river bank. The ecological filter tank isolates river water by sealing the tank body (100), a support structure is arranged below the ecological filter tank at a set height from the bottom thereof, a modular filler layer is supported above the support structure to treat the river bank sewage introduced into the ecological filter tank, and the space below the support structure is not filled with filler; The modular filler layer is arranged in three layers from bottom to top, which are a mineral particle layer (210) at the bottom, a bioreactor layer (220) at the middle, and an ecological layer (230) at the top. The mineral particle layer (210) is filled with natural mineral particles or treated natural mineral particles and is used for filtering sewage along the river bank, absorbing pollutants and biodegrading; The bioreactor layer (220) has a filler of suspended small balls for carrying biofilms, and uses the biofilms to reduce pollutants in sewage along the river bank; The ecological layer (230) is filled with fillers capable of supporting the growth of aquatic plants; The river sewage entering the biofilter is input into the mineral particle layer (210) through the water inlet pipe (240), and then enters the bioreactor layer (220) and the ecological layer (230) from bottom to top in sequence; The mineral particle layer (210) is composed of limestone and zeolite, with a mixing ratio of 1:(2-6); the filler particle size is 5-30 mm; the thickness of the mineral particle layer (210) is 30-60 cm; The filler in the mineral particle layer (210) is filled in a wire cage; The suspended small balls used to load the biofilm in the bioreactor layer (220) are microporous hollow balls filled with polyurethane sponge; the diameter of the microporous hollow balls is 10-20 mm; the mesh size of the microporous hollow balls is 40-100 meshes; The height of the bioreactor layer (220) is 30 cm to 60 cm, the filling height of the microporous hollow balls is 1 / 2 to 2 / 3 of the height of the bioreactor layer (220); the filling ratio of the polyurethane sponge in the microporous hollow balls is 60% to 80%; The filler of the bioreactor layer (220) is filled in a box having through holes distributed at the bottom and an opening at the top, and after being treated by the mineral particle layer (210), the sewage enters the bioreactor layer (220) through the through holes at the bottom of the box; The filler of the ecological layer (230) is ceramsite crushed particles, the filling height of the filler is 40-50 cm, and the particle size of the ceramsite crushed particles is 5-10 mm; The filler of the ecological layer (230) is filled in an open box with through holes distributed at the bottom, and the sewage enters the ecological layer (230) through the through holes at the bottom of the box after being processed by the bioreactor layer (220); The height of the open box is higher than the height of the filler filled therein, and a filter is fixed on the surface of the filler to position the filler below so that a clear cross section is formed between the filler and the upper water outlet; The ecological filter tank comprises a return water channel I (310) connecting the open box of the ecological layer (230) and the closed box of the bioreactor layer (220), a return water channel II (320) connecting the open box of the ecological layer (230) and the metal wire cage of the mineral particle layer (210), and a water pump for providing water circulation power; The water pump extracts water from the upper part of the filler of the ecological layer (230) and transports it to the bottom of the side of the closed box of the bioreactor layer (220) through the return water channel I (310); The water pump extracts water from the upper part of the filler of the ecological layer (230) and transports it to the filler of the mineral particle layer (210) through the return water channel II (320); The return water channel I (310) and the return water channel II (320) are both thin-diameter water delivery pipes, with a diameter of 1.6 to 3.0 cm.

2. The ecological filter according to claim 1, characterized in that: The body (100) of the ecological filter tank is a closed structure made of concrete or glass that can isolate river water; The support structure arranged below the ecological filter tank comprises a plurality of bars connecting two arbitrary sides of the tank body (100), a metal wire mesh (250) being laid on the bars, and the bars and the metal wire mesh (250) are capable of stably supporting the modular filler layer.

3. The ecological filter according to claim 1, characterized in that: Two to three layers of filter screens (260) are fixed in the interval from the support structure to the bottom of the ecological filter tank, and the mesh size of the filter screens (260) gradually decreases from top to bottom.

4. The ecological filter according to any one of claims 1 to 3, characterized in that: An inspection well (400) is constructed on the side of the pool body (100) against the river bank, and a suction pipe is arranged in the well. The suction pipe can penetrate into the ecological filter tank and enter the area from the support structure to the bottom of the ecological filter tank. When the ecological filter tank is desilted, the sediment at the bottom of the ecological filter tank is pumped out by turning on a pump that provides suction power to the suction pipe.

5. A method for preventing and controlling river pollution, using the ecological filter tank described in any one of claims 1 to 4 to prevent and control river pollution.

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