CN114684928B

CN114684928B - Ecological net for blocking and purifying non-point source pollutants on ridge and application of ecological net

Info

Publication number: CN114684928B
Application number: CN202210286198.9A
Authority: CN
Inventors: 杨龙
Original assignee: China Urban Construction Design and Research Institute Co Ltd
Current assignee: China Urban Construction Design and Research Institute Co Ltd
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-11-04
Anticipated expiration: 2042-03-23
Also published as: WO2022267649A2; ZA202204346B; CN114684928A; WO2022267649A3

Abstract

The invention provides an ecological network for intercepting and purifying non-point source pollutants by using ridges and application thereof, belonging to the technical field of farmland protection. The ecological net comprises: the packing layer comprises at least one packing unit bag, the packing unit bag consists of a water-permeable mesh bag, an outer anchor button and a zipper, and a complexing agent packing is filled in the water-permeable mesh bag; the composite filler comprises a supported magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a polyphosphate microbial inoculum and a nitrification inhibitor; the fixed bed, the packing layer with the fixed bed is by last to can dismantle the setting down, the fixed bed includes the fixed network, the fixed network includes thick net twine, thin net twine one, thick net twine is the frame of fixed network, thick net twine and thin net twine one are the cross setting. The ecological net is mainly used for intercepting and purifying nitrogen and phosphorus pollutants in farmland effluent, has a good effect, and can be directly recycled.

Description

Ecological net for blocking and purifying non-point source pollutants in ridge and application of ecological net

Technical Field

The invention belongs to the technical field of farmland protection, and particularly relates to an ecological network for intercepting and purifying non-point source pollutants in a field ridge and application thereof.

Background

The nutrients such as nitrogen (N) and phosphorus (P) are not only important suppliers of agricultural ecosystem productivity, but also are easily lost. With the effective treatment of point source pollution, the influence of agricultural non-point source pollutants such as nitrogen and phosphorus on the water environment quality is increasingly prominent. Particularly, the farmland contains nitrogen and phosphorus which are not absorbed by plants, and pollutants such as nitrogen and phosphorus carried after irrigation or rainfall, and if the farmland is discharged into the environment, serious pollution problems such as eutrophication and even black and odorous water bodies nearby are easily caused.

Substances such as nitrogen, phosphorus and the like in farmland irrigation water or rainwater runoff are absorbed by crops and soil microorganisms, and the other part of substances enter a water body in a manner of infiltration, direct drainage or seepage measurement and the like. The method is an important way for measuring the seepage into the water body of the ditch through the ridges, and particularly in the ridges with strong permeability such as sandy soil and humus, the measured seepage accounts for 60-70% of the total water displacement, so that the method becomes a main cause of non-point source pollution of agriculture.

The technology commonly used for intercepting and purifying nitrogen, phosphorus and other pollutants on the field ridge comprises an ecological field ridge, an ecological bag, vegetation greening and the like, and the interception and purification of nitrogen, phosphorus and other substances in farmland return water are realized mainly by using the principles of matrix adsorption, plant absorption, microbial degradation and the like. However, the filling and plant interception and purification technology adopted in the ecological ridge needs excavation construction, and has the condition limitations of high construction cost, large occupied space, difficult maintenance and the like. The adopted matrix filler has the functions of adsorption or plant interception and purification, and has the problems of limited adsorption capacity, poor effect, incapability of high-efficiency recycling, high filler updating cost, inconvenience for popularization and utilization and the like.

Disclosure of Invention

The invention provides an ecological net for intercepting and purifying non-point source pollutants on a ridge and application thereof, and aims to solve the problems that the existing farmland returned water interception and purification technology for pollutants such as nitrogen, phosphorus and the like is poor in effect, cannot be efficiently recycled and the like.

The invention provides an ecological network for intercepting and purifying non-point source pollutants on a ridge, which comprises:

the packing layer comprises at least one packing unit bag, each packing unit bag consists of a permeable mesh bag, a zipper and an outer anchor button, and the permeable mesh bag is filled with a complexing agent; wherein the complexing agent filler comprises a loading magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a polyphosphate bacterial agent and a nitrification inhibitor;

the fixed bed, packing layer and fixed bed can be dismantled the setting by last to lower, and the fixed bed includes the fixed network, and the fixed network includes thick net twine, thin net twine one, and thick net twine is the frame of fixed network, and thick net twine is the cross setting with thin net twine one, and the cross department of thick net twine is equipped with the interior anchor that is used for connecting outer anchor and detains, and the frame of thick net twine both sides links outward has the rivet ring that is used for connecting the rivet.

Furthermore, the mass ratio of the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the polyphosphate bacterial agent and the nitrification inhibitor is (1-4): 1-2): 0.5-1 ]: 0.5-1): 0.5-2): 1-6.

Further, the nitrification inhibitor includes at least one of 2-chloro-6 (trichloromethyl) pyridine, dicyandiamide, 3,4-dimethylpyrazole phosphate, or acetylene.

Further, the phosphorus accumulating agent comprises at least one of the genera Acinetobacter, aeromonas, pseudomonas, and Corynebacterium.

Further, the magnesium source loading agent comprises at least one of magnesium hydroxide modified fly ash, magnesium modified sepiolite or magnesium loaded natural zeolite.

Further, the biological carbon adsorbent comprises at least one of corn stalk biological carbon, peanut shell biological carbon or corncob biological carbon;

the pH regulator comprises at least one of limestone, papermaking waste lime mud or oyster shell.

Furthermore, the ecological net comprises at least one fixed layer, and the fixed layers are laid on the ridges in parallel.

Furthermore, the fixing net further comprises a second fine net wire, the second fine net wire and the thick net wire are arranged in a crossed mode, and the crossed position of the second fine net wire and the thick net wire is not provided with an inner anchor buckle.

Furthermore, the number of the filler unit bags is 1-20, and the filler unit bags are laid on the fixed layer side by side along the horizontal side line.

The invention also provides application of any one of the ecological nets in intercepting and purifying nitrogen and phosphorus pollutants in farmland returned water.

The invention has the following advantages:

the ecological net for intercepting and purifying the non-point source pollutants on the ridges has the advantages of simple and reasonable structural design, convenience in use and replacement and lower cost. The special packing layer is added and used for intercepting nitrogen and phosphorus pollutants in field ridge farmland backwater, and the problems that the nitrogen and phosphorus pollutants are poor in intercepting and purifying effect, difficult to recycle and the like can be effectively solved.

According to the ecological net provided by the invention, the fixing layer and the packing layer are detachable by arranging the inner anchor button, the outer anchor button, the rivet ring and the rivet, so that the ecological net is convenient to replace and maintain, and the cost is effectively reduced. The ecological net can be directly laid on the ridge without earth excavation, so that field water is effectively prevented from directly contacting with soil layers on the inner side of the ridge, and nitrogen and phosphorus in the soil are prevented from measuring and permeating into water bodies on the outer side of the ridge.

In the ecological net provided by the invention, the filler layer is internally provided with the complexing agent filler prepared by a load magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a phosphorus-accumulating microbial agent, a nitrification inhibitor and the like according to a certain proportion, and all components play a synergistic effect, so that pollutants such as nitrogen, phosphorus and the like in farmland return water can be effectively intercepted and purified, and meanwhile, the intercepted and generated precipitate can be directly used as a fertilizer for soil fertility improvement, thereby realizing recycling.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic front structure diagram of an ecological net in embodiment 1 of the present invention;

FIG. 2 is a schematic structural view of a fixing net in embodiment 1 of the present invention;

FIG. 3 is a schematic view of a structure of a packing unit bag in embodiment 1 of the present invention;

FIG. 4 is a schematic view of the usage status of the ecological network in embodiment 1 of the present invention;

FIG. 5 shows TN and NO when the ecological nets according to examples 1 to 3 of the present invention and comparative examples 1 to 3 are used for farmland drainage treatment ₃ ^- -N、NH ₃ -N, TP and PO ₄ ^3- -the removal rate of P;

FIG. 6 shows NH in the field treatment of the ecological nets according to examples 1 to 3 of the present invention and comparative examples 1 to 3 ₃ -N、PO ₄ ^3- -recovery of P;

description of reference numerals:

1 filling unit bags; 11, a water permeable mesh bag; 12, a zipper; 13 outer anchor buttons;

2, fixing a net; 21, coarse mesh wire; 22 a first fine mesh wire; 23, a second fine mesh wire; 24 inner anchor buttons; 25 rivet rings; 26 rivet(s).

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The embodiments and features of the embodiments of the invention may be combined with each other without conflict.

The inventor of the application finds that farmland irrigation or rainwater is retained in a farmland, and the permeation and drainage retention time for measuring seepage is long, so that the interception and absorption of pollutants such as nitrogen, phosphorus and the like through a percolation net become a better choice. And farmland irrigation water or rainwater and the like hold water, a water-soil interface and a water-gas interface are fully interacted, the oxygen content is high, nitrification is easily generated, nitrate serving as a product is easy to migrate and eluviate in soil, the utilization rate of agricultural nitrogen fertilizer is low, and surface water and underground water are easily polluted. In view of this, it is of great significance to provide a complexing agent filler and an ecological network which can effectively inhibit the generation of nitrification and intercept and purify nitrogen and phosphorus pollutants.

Referring to fig. 1-3, an embodiment of the present invention provides an ecological network for intercepting and purifying non-point source pollutants in a ridge, including:

the packing layer comprises at least one packing unit bag 1, the packing unit bag 1 consists of a water permeable mesh bag 11, an outer anchor button 13 and a zipper 12, and the water permeable mesh bag 11 is filled with a complexing agent; wherein the complexing agent filler comprises a loading magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a polyphosphate bacterial agent and a nitrification inhibitor;

the fixed bed, packing layer and fixed bed can be dismantled the setting by last to lower, and the fixed bed includes fixed network 2, and fixed network 2 includes thick net twine 21, thin net twine 22, and thick net twine 21 is the frame of fixed network 2, and thick net twine 21 is the cross setting with thin net twine 22, and the cross department of thick net twine 21 is equipped with the interior anchor of being used for connecting outer anchor 13 and detains 24, and the frame of thick net twine 21 both sides links outward has the rivet ring 25 that is used for connecting rivet 26.

The ecological network for intercepting and purifying the non-point source pollutants on the ridge provided by the embodiment of the invention has simple and reasonable structural design, realizes the disassembly of the fixed layer and the packing layer by arranging the inner anchor button, the outer anchor button, the rivet ring and the rivet, is convenient to replace and maintain, and effectively reduces the cost. The ecological net can be directly laid on the ridge without earth excavation, so that field water is effectively prevented from directly contacting with the soil layer on the inner side of the ridge to erode nitrogen and phosphorus in eluvial soil, and the ecological net is measured to permeate into the water body on the outer side of the ridge to play a role in soil conservation. The filler layer is internally provided with a complexing agent filler which is prepared by a load magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a phosphorus-accumulating microbial agent, a nitrification inhibitor and the like according to a certain proportion, and the complexing agent filler is used for intercepting nitrogen and phosphorus pollutants in the farmland which is running off in a ridge, not only can effectively intercept the nitrogen and phosphorus pollutants, but also can directly serve as a fertilizer for fertilizing the farmland by using a precipitate generated during interception, so that the problems of poor interception and purification effects of the nitrogen and phosphorus pollutants, difficult recycling and the like are effectively solved.

Referring to fig. 2, in an embodiment of the present invention, the fixing net 2 further includes a second thin net thread 23, the second thin net thread 23 is crossed with the thick net thread 21, and the crossing portion of the second thin net thread 23 and the thick net thread 21 is not provided with the inner anchor button 24. The second fine mesh wire 23 is mainly used to improve the stability of the fixing net 2.

Specifically, the mesh of the grid formed by the thick mesh wire 21 and the thin mesh wire one 22 or the thin mesh wire two 23 is 5-10cm. The thick mesh wire 21, the first fine mesh wire 22 or the second fine mesh wire 23 are all cylindrical ropes, and only the diameters of the ropes are different. It should be noted that the diameter of the rope here refers to the diameter of a circle of thick section of the rope. The diameter of the thick mesh wire 21 is 0.3-0.8mm. The thick mesh wire with the diameter is adopted so as to be convenient for stably arranging the inner anchor button on the inner anchor button. The diameter of the first fine mesh wire 22 or the second fine mesh wire 23 is 0.15-0.3mm.

In an embodiment of the present invention, the fixing net 2 has a rectangular structure. The ecological net comprises at least one fixed layer. Preferably, the ecological net can comprise one fixed layer, two fixed layers or three fixed layers, and the fixed layers are laid on the ridges in parallel. Specifically, the fixed layers are laid on the ridges in parallel from top to bottom. Referring to fig. 2, the ecological network comprises two fixed layers which are laid on the ridge in parallel to expand the area of the ecological network.

Specifically, the ecological net for the ridge to intercept and purify the non-point source pollutants can be (0.5-1) m by (1-100) m in specification, and can be flexibly prepared and laid according to the shape and area of the ridge.

Preferably, the fixing net 2 can be directly laid on the inner side of the ridge. The landform and the landform of the ridge and the soil vegetation do not need to be damaged, the earthwork excavation construction is not needed, and the economic cost is reduced. More preferably, in use, the rivets (26) are used to lay the net (2) on the ridge by means of the rivet ring (25).

In one embodiment of the invention, the number of the packing unit bags 1 in the packing layer is 1-20. The packing unit bags 1 on each fixed layer are laid side by side along a horizontal edge line. The number of the filling unit bags 1 can be 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 15, 20 and the like, and the filling unit bags can be flexibly prepared and paved according to the shape and the area of the ridge.

Specifically, the water permeable mesh bag 11 is a polyethylene mesh bag. Wherein the aperture of the polyethylene mesh cloth is 0.5-10mm. The polyethylene mesh cloth bag has meshes, so that farmland water discharge and illumination energy can be ensured to enter the filler, conditions are provided for exchanging substances of nitrogen and phosphorus in water with a complexing agent, and temperature and illumination are provided for growth of filler microorganisms. Preferably, the water permeable mesh bag 11 may have a size of (0.5-1) m x (0.5-1) m.

Preferably, the filling of the compound is made to fit into the filler unit bag 1 by opening the zipper 12. In the filling unit bag 1, the filling of the complexing agent accounts for 1/2 to 2/3 of the total volume of the filling unit bag 1.

In the embodiment of the invention, the composite agent filler in the filler layer mainly comprises a loaded magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a phosphorus-accumulating bacteria agent and a nitrification inhibitor, and the components have comprehensive effects, so that the proper pH and dissolved oxygen concentration required by nitrogen and phosphorus interception and purification can be provided, the nitrification rate is reduced, the form of nitrogen and phosphorus is regulated, the ammonium ion and phosphate ion concentrations around the filler layer are improved, and the ammonium ion and phosphate ion concentrations in field water are converted into slow-release fertilizer precipitated Mg (NH) under the action of the loaded magnesium source agent ₄ )PO ₄ ·6H ₂ And O, the interception of nitrogen and phosphorus pollutants is realized, and meanwhile, the recovery rates of phosphate and ammonia nitrogen are improved.

Specifically, the loaded magnesium source agent mainly reacts with ammonium ions and phosphate ions in field water retention to realize the transformation of nitrogen and phosphorus forms and generate insoluble solid Mg (NH) ₄ )PO ₄ ·6H ₂ And O, reducing the pollutants such as nitrogen and phosphorus from permeating into the ridges and then entering the water environment. The nitrification inhibitor is used for preventing ammonium nitrogen in the water body from being converted into nitrate nitrogen, regulating the form of nitrogen, improving the concentration of ammonium ions in the water body and generating the slow-release fertilizer Mg (NH) ₄ )PO ₄ ·6H ₂ O provides stable ammonium ions and is also beneficial to the absorption of field plants. The polyphosphate accumulating microbial inoculum not only plays a role of rapidly fixing soluble phosphate in farmland backwater on a filler layer, but also can release redundant phosphate in a cell body in a soluble monophosphate mode under an anaerobic environment to generate MgNH ₄ PO ₄ ·6H ₂ O provides stable phosphate ions. The biological carbon adsorbent can adsorb and remove various pollutants in the water body and provide a carbon source and a carrier for the growth of the microorganism bacteria. The pH regulator is biological microbial inoculum and generates Mg(NH ₄ )PO ₄ ·6H ₂ The O normal reaction provides a suitable alkalinity environment. The slow-release oxygen agent provides proper dissolved oxygen conditions for the growth and the phosphate absorption of early phosphorus accumulating bacteria.

In a preferred embodiment of the invention, the nitrification inhibitor comprises 2-chloro-6 (trichloromethyl) pyridine (2-chloro-6 (trichloromethyl) pyridine, CP), dicyandiamide (DCD), 3,4-dimethylpyrazole phosphate (DMPP), acetylene (C) ₂ H ₂ ) At least one of them. For example, nitrification inhibitors include 2-chloro-6 (trichloromethyl) pyridine, dicyandiamide, 3,4-dimethylpyrazole phosphate and acetylene. As another example, the nitrification inhibitor includes any one or any two or any three of 2-chloro-6 (trichloromethyl) pyridine, dicyandiamide, 3,4-dimethylpyrazole phosphate, or acetylene. In the embodiment of the invention, the problem of the non-point source pollution of the ridge is fully considered, and the nitrification inhibitor is added into the filler for the first time, is used for preventing the ammonium nitrogen in the water body from being converted into nitrate nitrogen, adjusting the form of nitrogen, improving the concentration of ammonium ions in the water body and generating the slow-release fertilizer Mg (NH) ₄ )PO ₄ ·6H ₂ O provides stable ammonium ions.

In a preferred embodiment of the invention, the phosphorus accumulating agent comprises at least one of the genera Acinetobacter, aeromonas, pseudomonas, or Corynebacterium. For example, phosphorus accumulating agents include Acinetobacter, aeromonas, pseudomonas, and Corynebacterium. As another example, the phosphorus accumulating agent includes any one or any two or any three of Acinetobacter, aeromonas, pseudomonas, or Corynebacterium. In the embodiment of the invention, the phosphorus-accumulating microbial agent can ensure that farmland drainage containing phosphorus element entering the filler layer and the periphery of the filler layer is accumulated in cells under an aerobic (or anoxic) state; when subjected to extremely adverse conditions, such as when the bacterial species rapidly grow to create an anaerobic environment, the polyphosphate accumulated in the cells is decomposed and released. Namely, the phosphorus-accumulating bacteria agent not only can quickly fix the soluble phosphate in farmland backwater on the filler layer, but also can release the redundant phosphate in the cells in a soluble monophosphate mode under the anaerobic environment to generate MgNH ₄ PO ₄ ·6H ₂ O provides stable phosphate ions.

In a preferred embodiment of the present invention, the magnesium source-carrying agent comprises at least one of magnesium hydroxide modified fly ash, magnesium modified sepiolite or magnesium-carrying natural zeolite. For example, the supported magnesium source agent includes magnesium hydroxide-modified fly ash, magnesium-modified sepiolite, and magnesium-supported natural zeolite. For another example, the supported magnesium source agent includes any one or any two or any three of magnesium hydroxide modified fly ash, magnesium modified sepiolite or magnesium-supported natural zeolite. In the embodiment of the invention, the loaded magnesium source agent is used as one of the main raw materials to provide Mg ²⁺ With NH in farmland return water ₄ ⁺ And PO ₄ ^3- Precipitation reaction takes place to form Mg (NH) ₄ )PO ₄ ·6H ₂ And O, promoting the fixation of nitrogen and phosphorus.

In a preferred embodiment of the invention, the magnesium hydroxide modified fly ash. Can be obtained by conventional preparation method. Specifically, the magnesium hydroxide modified fly ash can be prepared by the following preparation method, which comprises the following steps: selecting fly ash particles with the screening particle size of 1-10mm, washing the fly ash particles for a plurality of times by adopting ultrapure water, and drying the fly ash particles to constant weight at the temperature of 105 +/-1 ℃; 1g of dried fly ash is put into 50mL of deionized water, and 6mmol of MgCl is added respectively ₂ ·6H ₂ O, stirring for 1h in a magnetic stirrer (the rotating speed is 250r/min, the temperature is 25 ℃), and then adding Mg to OH ^- Adding NaOH according to the proportion of 1.5 (mol: mol) of =1, continuously stirring for 8h, performing suction filtration and washing, drying in an oven at 105 ℃ for 9h, and grinding until the particle size is less than 150 μm to obtain the magnesium hydroxide modified fly ash material.

Preferably, the biochar adsorbent comprises at least one of corn stalk biochar, peanut shell biochar or corncob biochar. For example, biochar adsorbents include corn stover biochar, peanut shell biochar, and corn cob biochar. For another example, the biochar adsorbent comprises any one or any two or any three of corn stalk biochar, peanut shell biochar and corn cob biochar. In the embodiment of the invention, the biological carbon adsorbent has rich surface functional groups, large specific surface area and stable chemical properties, can remove various pollutants in water through the actions of ion exchange, adsorption, complexation and the like, and provides a carbon source and a carrier for the growth of microorganisms.

Preferably, the pH adjusting agent includes at least one of limestone, papermaking waste lime mud, or oyster shell. The main component of the papermaking waste lime mud is calcium oxide which can be used as a regulator to regulate the pH value of a system. Preferably, the pH regulator comprises limestone, papermaking waste lime mud and oyster shell. In another example, the pH regulator comprises one or two or three of limestone, papermaking waste lime mud and oyster shell. In the embodiment of the invention, the pH regulator is used for improving the pH value content in water, the growth of the polyphosphate accumulating bacteria provides a proper acid-base environment, a more proper alkalinity environment and dissolved oxygen conditions are provided for forming magnesium ammonium phosphate crystals by phosphate ions, magnesium ions and ammonium ions, and metal ions are combined with phosphate in water to produce precipitates and remove phosphate.

Preferably, the preparation method of the slow-release oxygen agent can be directly referred to the literature (Hemobelin et al. Preparation method of the embedded calcium peroxide zeolite slow-release oxygen agent and research on improving black and odorous water [ J ]. Fujian quality management 2020, (5), 186-187.). The slow-release oxygen agent can provide proper dissolved oxygen for the growth and the absorption of phosphate by early phosphorus accumulating bacteria, so that the dissolved oxygen condition in the system is optimal.

In a preferred embodiment of the invention, the mass ratio of the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the polyphosphate bacterial agent and the nitrification inhibitor is (1-4): 1-2): 0.5-1): 0.5-2): 1-6. Preferably, the mass ratio of the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the polyphosphate bacterial agent and the nitrification inhibitor is 3.

In the embodiment of the invention, different components play different roles in the system, so the proportion of the components is different. The loaded magnesium source agent mainly provides magnesium ions to react with ammonium ions and phosphate ions in pollutants, the direct removal of nitrogen and phosphorus pollutants is directly influenced by too low addition amount, and the reaction rate is influenced by too high addition amount. The nitrification inhibitor and the polyphosphate microbial inoculum can effectively adjust the forms of nitrogen and phosphorus, and the nitrification inhibitor is added too little, so that ammonium ions in the solution are easily converted into nitrate nitrogen and cannot be effectively combined with magnesium ions and phosphate ions to influence the removal of the nitrogen and phosphorus. The phosphorus-accumulating microbial inoculum mainly absorbs phosphate ions in water, the adding amount of the phosphorus-accumulating microbial inoculum is too small, the phosphate concentration cannot be effectively accumulated in the composite filler bag, and the phosphate concentration cannot be combined with magnesium ions and ammonium ions to generate crystals, so that the adsorption effect of the biochar is influenced. The biological carbon adsorbent can adsorb and remove various pollutants in a water body, provide a carbon source and a carrier for the growth of the microorganism bacteria, and is not beneficial to the system reaction when the carbon source is too high or too low. The pH regulator and the oxygen-releasing agent provide proper alkalinity environment and dissolved oxygen condition for the normal reaction of the system, and proper amount of the pH regulator and the oxygen-releasing agent also needs to be added, and the normal operation of the reaction of the system is influenced by over-high and over-low conditions.

In the embodiment of the invention, the selected raw material loaded magnesium source agents such as magnesium hydroxide modified fly ash, biological carbon adsorbent, slow-release oxygen agent and the like are obtained by treating wastes, and the purposes of recycling the wastes and treating wastes with processes of wastes against one another can be achieved.

The embodiment of the invention also provides a preparation method of the complexing agent filler, which is prepared by mixing the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the polyphosphate bacterial agent and the nitrification inhibitor.

Referring to fig. 4, an embodiment of the present invention further provides an application of any of the above ecological nets in intercepting and purifying nitrogen and phosphorus pollutants in farmland returned water. The farmland water discharge comprises water discharge after irrigation, water discharge after rainfall runoff and the like. The ecological net is mainly used for being laid on a ridge and also can be laid on one side of a farmland ditch close to the ridge to intercept and purify pollutants in farmland drainage.

The ecological network provided by the embodiment of the invention can enrich phosphorus elements, adjust the storage form of nitrogen and phosphorus in farmland returned water, the pH value of a microenvironment, the oxygen content and other conditions, enhance the conversion of the form of nitrogen and phosphorus in farmland water rich in ammonia nitrogen and phosphate to a solid state, form a form of nitrogen and phosphorus which can be intercepted and utilized, prevent nitrogen and phosphorus pollutants from entering the water environment through ridge detection, form a slow release fertilizer, promote crops to be absorbed and utilized, improve the yield of the crops, and finally realize interception, purification and recycling.

Specifically, the ecological net provided by the invention can achieve the purpose of directly intercepting nitrogen and phosphorus pollutants. On one hand, the solid particles which adsorb dissolved substances in farmland water can be directly intercepted. On the other hand, as the composite agent filler contains the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the phosphorus-accumulating microbial agent, the nitrification inhibitor and the like, soluble nutrients in farmland water can be promoted to be converted into insoluble solids, and pollutants such as nitrogen, phosphorus and the like are reduced to permeate into ridges and water environment, so that the pollutants are intercepted.

The ecological net provided by the invention can form the nitrogen and phosphorus form absorbed by crops when promoting the nitrogen and phosphorus form transformation in farmland water, and can also form a slow release fertilizer MgNH easy to be absorbed and utilized by crops ₄ PO ₄ ·6H ₂ O, along with the trapped nutrient substances, is converted into a reusable fertilizer which can be placed on the ridge for a long time and used for fertilizing soil on the ridge, is convenient to adjust and maintain, and has obvious effects on agricultural non-point source pollution treatment, water environment quality improvement and nitrogen and phosphorus resource recovery.

The embodiment of the invention also provides a method for intercepting nitrogen and phosphorus pollutants in farmland returned water by using the ecological network, which comprises the following steps: opening the zipper 12 on the filling unit bag 1, filling the composite agent into the filling unit bag 1, and sealing the zipper 12; the outer anchor button 13 is pressed and combined with the inner anchor button 24 on the fixed layer to connect the filler layer and the fixed layer together; fixing the fixing layer on the ridge by rivets 26 through rivet rings 25 on the fixing net; each packing unit bag 1 on the fixed layer is laid on the ridge side by side along the horizontal edge line, and each fixed layer of the ecological net is laid on the ridge side by side; when the farmland drainage to be treated passes through the ecological net, the interception and purification of nitrogen and phosphorus pollutants in the farmland drainage can be realized, and the generated precipitate can be directly used as farmland fertilizer.

The present invention will be described in detail with reference to examples.

Example 1Ecological net for blocking and purifying non-point source pollutants on ridge

The ecological net includes:

each packing layer comprises six packing unit bags 1, and the packing unit bags 1 are laid side by side along a horizontal side line; the filling unit bag 1 consists of a water permeable mesh bag 11, an outer anchor button 13 and a zipper 12, and the water permeable mesh bag 11 is filled with a compound agent filling; the composite filler is prepared from a loaded magnesium source agent (magnesium hydroxide modified fly ash), a biological carbon adsorbent (corn stalks), a pH regulator (oyster shells), a slow-release oxygen agent, a phosphorus-accumulating bacteria agent (acinetobacter, aeromonas, pseudomonas and corynebacterium), a nitrification inhibitor (2-chloro-6 (trichloromethyl) pyridine) in a mass ratio of (3);

two fixed courses, the fixed course from the top down lays side by side, every packing layer and every fixed course can be dismantled the setting by last to the bottom, the fixed course includes fixed network 2 and rivet 26, fixed network 2 includes thick net twine 21, thin net twine one 22, thick net twine 21 is the frame of fixed network 2, thick net twine 21 is the cross setting with thin net twine one 22, the cross department of thick net twine 21 is equipped with the interior anchor that is used for connecting outer anchor and detains 13 and detains 24, the frame of thick net twine 21 both sides links outward has rivet ring 25 that is used for connecting rivet 26.

Example 2Intercepting filter screen for intercepting and purifying non-point source pollutants on ridge

The difference from example 1 is that the mass of the nitrification inhibitor is reduced by half, namely the mass ratio of the supported magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the polyphosphate bacterial agent and the nitrification inhibitor is 3.

Example 3Intercepting filter screen for intercepting and purifying non-point source pollutants on ridge

The difference from example 1 is that the mass of the added phosphorus-accumulating microbial agent is reduced by half, namely the mass ratio of the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the phosphorus-accumulating microbial agent and the nitrification inhibitor is 3.

Example 4Ecological net for blocking and purifying non-point source pollutants on ridge

The difference from example 1 is that the complexing agent filler is composed of a supported magnesium source agent (magnesium modified sepiolite), a biological carbon adsorbent (corncob biochar), a pH regulator (oyster shell), a slow-release oxygen agent, a phosphorus-accumulating bacteria agent (corynebacterium) and a nitrification inhibitor (dicyandiamide) according to a mass ratio of 3.

Comparative example 1Intercepting filter screen for intercepting and purifying non-point source pollutants on ridge

The difference from example 1 is that no polyphosphazene agent is added.

Comparative example 2A interception filter screen that is used for ridge interception to purify non-point source pollutant

The difference from example 1 is that no nitrification inhibitor is added.

Comparative example 3Intercepting filter screen for intercepting and purifying non-point source pollutants on ridge

The difference from example 1 is that no biochar adsorbent was added.

Test example 1Ecological network nitrogen and phosphorus pollutant removal rate and recovery performance test

6 groups of test experiments are set, the area of each group of field is 4 square meters, and rice is planted in the field. The compound filling materials prepared in the examples 1-3 and the comparative examples 1-3 are respectively placed on one side of the ridge to intercept, purify and recover filter screens, 4000L of water distribution, TN and NO are poured into each field block ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- The initial concentration of-P was 36.52mg/L, 20.87mg/L, 15.89mg/L, 2.95mg/L and 2.67mg/L, respectively. Sampling every 12 hours to detect TN and NO in water ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- P concentration, continuously monitored for 3 days for 6 times, and finally TN and NO were calculated ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- P removal Rate and NH ₃ -N、PO ₄ ³ Recovery of P.

Examples 1 to 3 and comparative examples 1 to 3, TN, NO ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- Comparison of-P removal rates in FIG. 5, NH ₃ -N、PO ₄ ^3- P recovery is compared with FIG. 6.

Referring to FIGS. 5 and 6, TN and NO of example 1 ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- P removal rates were respectively achievedTo 84.60%, 81.07%, 93.14%, 96.95%, 97.38%, NH ₃ -N、PO ₄ ³ The recovery rates of P and P reach 42.29% and 47.07% respectively. TN and NO in water body ₃ ^- -N、NH ₃ -N、TP、PO ₄ ^3- The concentration of P is reduced, the combined action of plant absorption, soil adsorption, ecological net filler purification and the like is mainly adopted, in 6 groups of experiments, other conditions are the same, the removal effect of the pollutants is different under the condition that only the ecological net complexing agent filler is different, and therefore, the removal effect of the pollutants is directly influenced by the ecological net complexing agent filler. Moreover, the ecological network has different nitrogen and phosphorus recovery effects, and further shows that different fillers or components have different interception and purification effects on nitrogen and phosphorus pollutants.

The removal rate and the recovery rate of nitrogen and phosphorus pollutants obtained in the examples 1-3 are better than those of the comparative examples 1-3, which shows that the effect of the composite filler provided by the application is obviously better than that of the comparative examples 1-3, namely, each component in the composite filler is indispensable. In example 2, the mass of the nitrification inhibitor was reduced by half compared to example 1. In example 3, the quality of the phosphorus-accumulating bacteria agent is reduced by half. The reduction of the nitrification inhibitor and the polyphosphate bacterial agent ensures that the loaded magnesium source agent cannot be fully combined with ammonium ions and phosphate ions, is used for reacting to generate magnesium ammonium phosphate, intercepts nitrogen and phosphorus, properly reduces the reaction effect and further influences the removal rate and the recovery rate of the nitrogen and phosphorus.

In the comparative example 1, the phosphorus-adding microbial inoculum is not added, the phosphate concentration can not be effectively gathered in the composite filler bag, and can not be combined with magnesium ions and ammonium ions to generate crystals, and the adsorption effect of the biochar can also be reduced, so that the removal rate of the phosphate concentration is obviously reduced, and the recovery rate of nitrogen and phosphorus is influenced.

In comparative example 2, NO nitrification inhibitor was added, and ammonium ions in the solution were easily converted into nitrate nitrogen and could not effectively bind with magnesium ions and phosphate ions, resulting in TN and NO in the solution ₃ ^- -N、NH ₃ the-N removal rate is low. Meanwhile, phosphate ions cannot be combined with magnesium ions due to lack of ammonium ions, so that the removal rate and the recovery rate of phosphorus are influenced.

In the comparative example 3, no biochar adsorbent is added, so that the adsorption quantity of nitrogen and phosphorus elements generated by biochar is influenced, and biological bacteria such as phosphorus accumulating bacteria and denitrifying bacteria lack carbon sources and carriers required by growth and influence the removal rate and recovery rate of nitrogen and phosphorus.

Therefore, all the components generate synergistic action to jointly form the interception and purification and the nitrogen and phosphorus recovery of the non-point source pollutant, and the interception and purification and the nitrogen and phosphorus recovery of the non-point source pollutant can be influenced by the absence of any one component or different proportions.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An ecological network for blocking and purifying non-point source pollutants on a ridge is characterized by comprising:

the packing layer comprises at least one packing unit bag (1), the packing unit bag (1) consists of a water permeable mesh bag (11), a zipper (12) and an outer anchor button (13), and the water permeable mesh bag (11) is filled with a composite agent packing; the composite filler comprises a supported magnesium source agent, a biological carbon adsorbent, a pH regulator, a slow-release oxygen agent, a polyphosphate bacterial agent and a nitrification inhibitor;

the packing layer and the fixing layer are detachably arranged from top to bottom, the fixing layer comprises a fixing net (2), the fixing net (2) comprises a thick net line (21) and a thin net line (22), the thick net line (21) is a frame of the fixing net (2), the thick net line (21) and the thin net line (22) are arranged in a cross manner, an inner anchor buckle (24) used for being connected with an outer anchor buckle (13) is arranged at the cross position of the thick net line (21), and rivet rings (25) used for being connected with rivets (26) are connected outside the frames on two sides of the thick net line (21);

wherein the mass ratio of the loaded magnesium source agent, the biological carbon adsorbent, the pH regulator, the slow-release oxygen agent, the phosphorus-accumulating microbial inoculum and the nitrification inhibitor is (1-4): 1-2): 0.5-1): 0.5-2): 1-6;

the nitrification inhibitor comprises at least one of 2-chloro-6 (trichloromethyl) pyridine, dicyandiamide, 3,4-dimethylpyrazole phosphate or acetylene;

the phosphorus-accumulating bacteria agent comprises at least one of acinetobacter, aeromonas, pseudomonas or corynebacterium.

2. The ecological net according to claim 1,

the magnesium source loading agent comprises at least one of magnesium hydroxide modified fly ash, magnesium modified sepiolite or magnesium loaded natural zeolite.

3. The ecological net according to claim 1,

the biological carbon adsorbent comprises at least one of corn stalk biological carbon, peanut shell biological carbon or corncob biological carbon;

4. The ecological net according to claim 1,

the ecological net comprises at least one fixed layer, and the fixed layers are laid on the ridges in parallel.

5. Ecological network according to claim 1,

the fixing net (2) further comprises a second fine net wire (23), the second fine net wire (23) and the thick net wire (21) are arranged in a crossed mode, and an inner anchor buckle (24) is not arranged at the crossed position of the second fine net wire (23) and the thick net wire (21).

6. The ecological net according to claim 1,

the number of the packing unit bags (1) is 1-20, and the packing unit bags (1) are laid on the fixed layer side by side along the horizontal side line.

7. The use of the ecological network of any one of claims 1 to 6 for intercepting and purifying nitrogen and phosphorus pollutants in farmland effluent.