CN113072190A - Unpowered undercurrent ecological sewage interception ditch system and construction method thereof - Google Patents

Abstract

The invention relates to an unpowered undercurrent ecological sewage interception ditch system which comprises a ditch main body, a filling bottom material supporting layer, a double-medium biological matrix layer and an ecological planting layer, wherein the filling bottom material supporting layer, the double-medium biological matrix layer and the ecological planting layer are laid in the ditch main body, and submerged plants and emergent plants are planted on the ecological planting layer. The construction method comprises the following steps: constructing a ditch main body of an inverted trapezoidal structure; laying an anti-seepage layer on the bottom of the ditch main body and the side slope; paving concrete and grouted pebbles to obtain a filling bed material supporting layer; mixing natural zeolite, porous ecological bricks, a curing agent, phosphate and a microorganism mixed powdery microbial inoculum, and laying the mixture on a filling backing material supporting layer to obtain a double-medium biological matrix layer; paving an ecological planting layer on the double-medium biological matrix layer; emergent aquatic plants and submerged plants are planted on the ecological planting layer. Establishing a proper living environment to form a benign micro-ecological succession structure of pollutant-microorganism-plankton-submerged/emergent aquatic plant, thereby strengthening the control of surface-source pollutants such as nitrogen and phosphorus in rural planting.

Description

Unpowered undercurrent ecological sewage interception ditch system and construction method thereof

Technical Field

The invention relates to the technical field of agricultural wastewater ecological treatment, in particular to an unpowered undercurrent ecological sewage intercepting ditch system and a construction method thereof.

Background

The agricultural non-point source pollution mainly refers to pollution caused by livestock and poultry breeding, soil particles, nitrogen, phosphorus, pesticides and other harmful substances in the farmland in the agricultural breeding production process, and pollution caused by the fact that surface runoff enters a receiving water body in the rainfall or irrigation process, and comprises livestock and poultry excrement loss, breeding fertilizer and pesticide pollution, straw pollution, domestic garbage which is not collected and treated, domestic sewage which cannot be collected and managed, water and soil pollution caused by farmland water and soil loss and the like.

The ecological ditch still has some problems to be solved urgently in practical application:

1) the removal efficiency of the pollutants by the common ecological ditch is not high;

2) the biodiversity is single, and the stability is insufficient;

therefore, in order to reduce pollution caused by agricultural non-point sources and the current requirement of beautiful ecological environment, by optimizing the layout of the ecological ditch, the unpowered undercurrent ecological pollutant intercepting ditch system which is beautiful, suitable for appreciation, ecological, environment-friendly and energy-saving and reduces the agricultural non-point source pollution is expected to be designed, so that the agricultural non-point source pollution is effectively intercepted, nitrogen, phosphorus and potassium of the agricultural wastewater are purified, and the pollution of nitrogen, phosphorus and phosphorus loss to the water environment is reduced.

Disclosure of Invention

The invention aims to solve the technical problem of providing an unpowered undercurrent ecological sewage intercepting ditch system and a construction method thereof, so as to overcome the defects in the prior art.

The technical scheme for solving the technical problems is as follows: the unpowered undercurrent ecological sewage intercepting ditch system comprises a ditch main body, and a filling bottom material supporting layer, a double-medium biological matrix layer and an ecological planting layer which are sequentially laid in the ditch main body, wherein the ecological planting layer adopts a mixed planting mode of submerged plants and emergent plants.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the trench body is curved.

Further, the trench body is wavy.

Furthermore, the ditch main bodies are distributed and arranged in terraces with natural fall according to slopes.

Furthermore, the trench body is an inverted trapezoid structure with a large top and a small bottom.

Further, the thickness ratio of the filling bottom material supporting layer, the double-medium biological matrix layer and the ecological planting layer is within the range of 1-2:2-4: 1-2.

And further, the filling bottom material supporting layer is lined in a mode of combining concrete and grouted pebbles, the width of the grouted pebble joints is less than 40mm, and the grouted pebbles are laid in a mode that the length of the grouted pebbles is vertical to the slope surface or the water flow direction.

Further, the double-medium biological matrix layer comprises natural zeolite, a porous ecological brick, a microorganism mixed powder microbial inoculum, a curing agent and silicate.

Further, the mixed powdery microbial inoculum of microorganism includes dephosphorization denitrogen bacterium paracoccus, flocculation bacteria agrobacterium and COD degradation bacterium bacillus, wherein, COD degradation bacterium bacillus: flocculation bacteria agrobacterium: the weight portion ratio of the dephosphatation denitrogen bacteria paracoccus is within the range of 1-3:0.3-1: 1-3.

Furthermore, the bottom of the ditch main body and the side slope are paved with anti-seepage layers.

Further, the impermeable layer is an HDPE geomembrane.

A construction method of an unpowered undercurrent ecological sewage intercepting ditch comprises the following steps:

s100, constructing a ditch main body of an inverted trapezoidal structure;

s200, paving an anti-seepage layer on the bottom of the ditch main body and the side slope;

s300, paving concrete and grouted pebbles to finish paving a filling bed material supporting layer;

s400, mixing and preparing natural zeolite, porous ecological bricks, a curing agent, phosphate and a microorganism mixed powdery bacterium agent according to a proportion, and paving the mixture on a backing material filling supporting layer to finish paving a double-medium biological matrix layer;

s500, paving an ecological planting layer on the double-medium biological matrix layer;

s600, planting emergent aquatic plants and submerged plants on the ecological planting layer.

The invention has the beneficial effects that:

combining ecological units with characteristics into an unpowered subsurface flow ecological sewage interception ditch system with dual functions of sewage purification and resource utilization according to a certain proportion and mode, wherein different ecological units realize the function of ecologically intercepting nitrogen and phosphorus through the processes of intercepting runoff and sediment by ditches, retaining and absorbing nutritive salt in water by plants, metabolizing microorganisms and the like, thereby realizing the purification of pollutants in farmland wastewater;

the curved ecological ditch system can form an ecological interception type ditch, reduce the water flow speed, increase the hydraulic retention time, promote the deposition of suspended substances and particulate matters in the flow and be beneficial to the degradation of pollutants;

the plant layer mainly removes 8% -16% of nitrogen through physical, chemical and biological effects; the root absorbs the inorganic phosphorus in a dissolved state, so that the concentration gradient difference of phosphorus is generated between the bottom mud of the root and the water body, and the migration of phosphorus from the water body to the bottom mud is increased; the microorganism can convert organic nitrogen into ammonia nitrogen through amination and mineralization under alkaline conditions; the microorganism can convert the organic phosphorus into inorganic phosphorus through the microbial action, and the inorganic phosphorus is absorbed and utilized by plants; in addition, the microorganisms can reduce the concentration and proportion of nitrogen and phosphorus in the water body through nitrification and denitrification;

according to the research of the literature, the following components are shown: more than 80% of nitrogen can be effectively removed under the action of the microorganisms, and some plants with developed root systems are properly selected, so that more attachment spaces can be provided for nearby microorganisms, and the degradation of macromolecular organic matters in the water body is accelerated; the method can form a benign micro-ecological succession structure of 'pollutant-microorganism-plankton-submerged/emergent aquatic plant' by screening high-efficiency indigenous plants, optimizing the configuration of fillers and establishing a proper biological habitat, thereby strengthening the control on surface-source pollutants such as nitrogen and phosphorus in rural planting industry, wherein the microorganism can slowly enter a water body, and the pollutants are subjected to physical processes such as matrix adsorption, filtration and precipitation and biochemical processes such as transformation and oxidative decomposition of the microorganism in the whole interception process, so that the substances polluted by the surface-source agriculture in the water body are finally intercepted;

after carrying out preliminary field investigation on the plant planting condition of the exemplary engineering implementation land, the water quality of the farmland of the exemplary land is found as follows: the concentration range of TN is 1-13mg/L, the concentration range of TP is 0.03-26 mg/L, the concentration range of ammonia nitrogen is 3.20-6.50mg/L, and the concentration range of COD is 17.5-36 mg/L;

the eutrophication is removed by adopting a single species, so that the problems of poor stress resistance, poor insect resistance and the like exist, the system fluctuation is large, the water quality purification effect is unstable, and the eutrophication water body purification effect is better than that of the eutrophication water body purification effect of the single species by adopting a mixed planting mode of submerged plants and emergent plants, so that the removal rate of nitrogen and phosphorus in the agricultural wastewater is increased, and the local ecological environment can be beautified; emergent aquatic plants have developed root systems, can provide attachment substrates and habitats for microorganisms, and the developed root systems are favorable for the growth of the microorganisms, so that the decomposition of organic colloids around the root systems can be accelerated; the submerged plant is the key for steady state and water quality improvement in the water system, has better removing capability on nitrogen and phosphorus nutrient salts and has stronger algae-restraining effect, so the ecological ditch adopts a mixed planting mode of the submerged plant and the emergent plant;

in addition, the waste ecological ditch system can be used for reconstruction, the original ecological drainage ditch is constructed into a ditch system which has a unique structure and plays an ecological function, and the construction can be carried out again according to the design requirement; the investment cost is low, the engineering implementation is simple, the treated agricultural wastewater can be recycled, and the method is suitable for preventing and controlling agricultural non-point source pollution and has double values of reducing environmental pollution and saving water resources.

Drawings

FIG. 1 is a cross-sectional view of the unpowered undercurrent ecological intercepting canal system of the present invention;

FIG. 2 is a plan view of the unpowered undercurrent ecological sewage intercepting canal system of the present invention, which can increase the hydraulic retention time of farmland wastewater in ecological canals and thereby increase the removal efficiency of pollutants.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the ditch comprises a ditch main body, 2, a filling backing material supporting layer, 3, a double-medium bio-matrix layer, 4, an ecological planting layer, 5 and an impermeable layer.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

Example 1

As shown in fig. 1 and 2, an unpowered undercurrent ecological sewage intercepting ditch system comprises a ditch main body 1, a filling bottommaterial supporting layer 2, a double-medium bio-matrix layer 3 and an ecological planting layer 4, wherein the filling bottommaterial supporting layer 2, the double-medium bio-matrix layer 3 and the ecological planting layer 4 are sequentially laid at the bottom of the ditch main body 1 from bottom to top, the ecological planting layer 4 adopts a mixed planting mode of submerged plants and emergent plants, and can effectively remove excessive nitrogen, phosphorus and potassium in an ecological ditch by adopting a mixed planting mode of various aquatic plants to achieve the effect of purifying water quality.

Example 2

As shown in fig. 1 and fig. 2, this embodiment is further optimized based on embodiment 1, and its specific scheme is as follows:

the trench body 1 is curved, preferably waved.

Example 3

As shown in fig. 1 and fig. 2, this embodiment is a further optimization performed on the basis ofembodiment 1 or 2, and the specific scheme thereof is as follows:

the ditch main body 1 is distributed and arranged by terraces with natural fall according to slopes, namely, the ditch system is distributed in the terraces with the slopes and is in a curve shape, and because of the slope with the natural fall, an additional water pump is not needed for conveying, and the problem of power conveying is solved.

Example 4

As shown in fig. 1 and fig. 2, this embodiment is further optimized based onembodiment 1, 2 or 3, and the specific scheme is as follows:

the ditch main body 1 is an inverted trapezoidal structure with a large upper part and a small lower part, the ditch walls on two sides are designed by adopting surface porous holes, and the side slopes are mainly lined. Example 5

As shown in fig. 1 and fig. 2, this embodiment is further optimized based on any one of embodiments 1 to 4, and the specific scheme is as follows:

the thickness ratio of the filling bottommaterial supporting layer 2, the double-medium biological matrix layer 3 and the ecological planting layer 4 is in the range of 1-2:2-4:1-2, and is preferably 1:2: 1.

Example 6

As shown in fig. 1 and fig. 2, this embodiment is further optimized based on any one of embodiments 1 to 5, and the specific scheme is as follows:

the filling bottommaterial supporting layer 2 is lined by adopting a mode of combining concrete and grouted cobbles, and the width of a grouted cobble joint is less than 40 mm; tamping the channel side slope and the bottom of the ditch, paving gravel cushion layers which are uniformly distributed and have the compactness of more than 90 percent, and paving grouted pebbles in a way that the length is vertical to the slope surface or the water flow direction when paving; the mixture is mixed with cement, sand and fine stone, and the diameter of the fine stone is 0.5-1cm according to the qualified inspection of relevant requirements.

Example 7

As shown in fig. 1 and fig. 2, this embodiment is further optimized based on any one of embodiments 1 to 6, and the specific scheme is as follows:

the double-medium biological matrix layer 3 comprises natural zeolite, porous ecological bricks, a microorganism mixed powder microbial inoculum, a curing agent and silicate;

typically, the dual-media bio-matrix layer 3 consists of the following weight numbers:

natural zeolite: 4 parts of porous ecological brick: 4, mixing a microorganism powder microbial inoculum: 3 parts of curing agent: 1 part of silicate: 1.5 parts; the natural zeolite is a green and cheap natural nonmetallic mineral material, has the advantages of large mineral reserve and large specific surface area, and has high selectivity for removing ammonia nitrogen. The porous ecological brick has the characteristics of ecological environment protection and low cost, can fix plants, and can also enhance the stability of the whole brick body and soil. The use of the curing agent and the silicate can accelerate the dispersion speed of the original particles and improve the coordination of the hydrate generation process.

The materials are mixed and prepared according to the proportion.

The surface microstructure of the porous ecological brick is beneficial to the growth and attachment of microorganisms, has higher phosphorus removal performance, can efficiently remove phosphorus pollution in agricultural wastewater,

the microorganisms can convert macromolecular organic matters in the agricultural wastewater into micromolecular substances and simultaneously generate carbon dioxide (CO)₂) Inorganic salt and growth factors provide a good ecological environment for the agricultural wastewater, promote the growth of microorganisms and increase the pollutant-cutting and removing capacity of nitrogen, phosphorus and potassium in the agricultural wastewater;

however, the zeolite has strong adsorbability to ammonia nitrogen, and can quickly intercept the ammonia nitrogen in the wastewater.

Example 8

As shown in fig. 1 and fig. 2, this embodiment is a further optimization based on embodiment 7, and its specific scheme is as follows:

the microorganism mixed powdery microbial inoculum comprises dephophorization and denitrogenation paracoccus, flocculation bacteria agrobacterium and COD degrading bacteria bacillus;

wherein, the COD degrading bacteria bacillus: flocculation bacteria agrobacterium: the weight portion ratio of the paracoccus of the dephosphorizing and denitriding bacteria is 1-3:0.3-1: 1-3. According to the early stage field investigation of water quality sampling analysis, the nitrogen and phosphorus content in the farmland wastewater is high, so that the weight parts of the COD degrading bacteria bacillus and the dephosphorizing and denitrifying bacteria paracoccus are high in proportion.

Example 9

As shown in fig. 1 and fig. 2, this embodiment is further optimized based on any one of embodiments 1 to 8, and the specific scheme is as follows:

the bottom of the channel main body 1 and the side slope are paved with theanti-seepage layer 5, so that the pollution of underground water is avoided, the whole channel main body 1 is subjected to waterproof treatment, and the problem of water leakage of the channel main body 1 is avoided; typically, thebarrier layer 5 is preferably a HDPE geomembrane.

Example 10

A construction method of an unpowered undercurrent ecological sewage intercepting ditch comprises the following steps:

s100, constructing a ditch main body 1 of an inverted trapezoidal structure, wherein in the process of constructing the ditch main body 1 of the inverted trapezoidal structure, the low-lying part of the ditch is backfilled, tamped and leveled, and the bottom of the ditch and the debris on the side slope are cleaned up to ensure smooth slope;

s200, paving an anti-seepage layer on the bottom of the channel main body 1 and the side slope, wherein the anti-seepage layer is an HDPE geomembrane, so that underground water pollution is avoided;

s300, paving concrete and grouted pebbles, wherein the flatness of the grouted pebbles is the standard (30mm) of grouted rubbles, the surfaces of the grouted pebbles are flat and compact, and the grouted pebbles are subjected to pointing by M10-grade cement mortar; the slump of the mortar is 4-5 cm, the strength of the mortar is in accordance with the design specification, the cement and sand water used by the mortar are qualified after the test of a test department, and can be used by a supervision and approval party, and the laying thickness is 10-20 cm, so that the laying of the backing material filling supportinglayer 2 is completed;

s400, mixing and preparing natural zeolite, porous ecological bricks, a curing agent, phosphate and a microorganism mixed powder bacterium agent according to a proportion, laying the mixture on a filling backingmaterial supporting layer 2, wherein the laying thickness is 20-40 cm, and finishing laying a double-medium biological matrix layer 3;

s500, paving an ecological planting layer 4 on the double-medium biological matrix layer 3, wherein the paving thickness is 10-20 cm;

s600, planting emergent aquatic plants and submerged plants on the ecological planting layer 4, planting bermudagrass on the side slope of the ditch main body 1, and planting on the bank of the ditch main body 1 to design greening vegetation.

The emergent aquatic plant can be rhizoma Acori Calami, canna, etc., and the submerged plant can be algae, herba Swertiae Dilutae, etc.

According to related research, the removal rate of TN (total nitrogen) of the ecological ditch can reach more than 50%, the removal rate of TP of the ecological ditch can reach more than 60%, and the removal rate of Chemical Oxygen Demand (COD) of the ecological ditch can reach more than 65%, so that nitrogen, phosphorus and other nutrient substances in a farmland are remarkably intercepted, and the pollution degree and the eutrophication degree of a water body are reduced. The method comprises the steps of screening high-efficiency indigenous plants, optimizing filler configuration, and establishing a proper biological habitat to form a benign micro-ecological succession structure of 'pollutant-microorganism-plankton-submerged/emergent aquatic plant', so that the control on surface-source pollutants such as nitrogen and phosphorus in the rice planting industry is enhanced, wherein the microorganism can slowly enter a water body, and the pollutants are subjected to physical processes such as matrix adsorption, filtration and precipitation and biochemical processes such as microorganism conversion and oxidative decomposition in the whole interception process, so that the agricultural surface-source polluted substances in the water body are finally intercepted.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (10)

1. The unpowered undercurrent ecological sewage intercepting ditch system is characterized by comprising a ditch main body (1), and a filling bottom material supporting layer (2), a double-medium biological matrix layer (3) and an ecological planting layer (4) which are sequentially laid in the ditch main body (1), wherein the ecological planting layer (4) adopts a mixed planting mode of submerged plants and emergent plants.

2. The unpowered subsurface flow ecological intercepting canal system according to claim 1, wherein the canal body (1) is curved.

3. The unpowered subsurface flow ecological intercepting canal system according to claim 1, wherein the canal body (1) is distributed by terraces with natural fall according to slopes.

4. The unpowered subsurface flow ecological intercepting sewer system according to any one of claims 1 to 3, wherein the sewer body (1) is an inverted trapezoidal structure with a large top and a small bottom.

5. The unpowered subsurface ecological intercepting sewer system according to claim 1, characterized in that the thickness ratio of the bottom-filled supporting layer (2), the double-medium bio-matrix layer (3) and the ecological planting layer (4) is in the range of 1-2:2-4: 1-2.

6. The unpowered subsurface flow ecological sewage intercepting canal system according to claim 5, wherein the bottom filling material supporting layer (2) is lined by combining concrete and grouted pebbles, the width of the grouted pebble joints is less than 40mm, and the grouted pebbles are laid in a manner that the length of the grouted pebbles is perpendicular to the slope surface or the water flow direction.

7. The unpowered undercurrent ecological intercepting sewer system according to claim 6, wherein the dual-medium bio-matrix layer (3) comprises natural zeolite, porous ecological brick, microorganism mixed powder microbial inoculum, curing agent and silicate.

8. The unpowered subsurface flow ecological sewage intercepting canal system according to claim 7, wherein the mixed microbial powdered inoculum comprises paracoccus denitrificans, agrobacterium flocculants and bacillus COD degrading bacteria, wherein the bacillus COD degrading bacteria: flocculation bacteria agrobacterium: the weight portion ratio of the paracoccus of the dephosphorizing and denitriding bacteria is 1-3:0.3-1: 1-3.

9. The unpowered subsurface flow ecological intercepting canal system according to claim 8, wherein the bottom and the side slope of the canal body (1) are paved with an anti-seepage layer (5).

10. A construction method of an unpowered undercurrent ecological sewage intercepting ditch is characterized by comprising the following steps:

s100, constructing a ditch main body (1) with an inverted trapezoidal structure;

s200, paving an anti-seepage layer on the bottom of the ditch main body (1) and a side slope;

s300, paving concrete and grouted pebbles to finish paving the filling bed charge supporting layer (2);

s400, mixing and preparing natural zeolite, porous ecological bricks, a curing agent, phosphate and a microorganism mixed powdery microbial inoculum according to a ratio, and paving the mixture on a filling backing material supporting layer (2) to finish paving a double-medium biological matrix layer (3);

s500, paving an ecological planting layer (4) on the double-medium biological matrix layer (3);

s600, planting emergent aquatic plants and submerged plants on the ecological planting layer (4).

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