CN110980955A - Treatment method of water ecosystem aiming at eutrophic water body - Google Patents

Abstract

The invention discloses a method for treating an aquatic ecosystem aiming at eutrophic water, which comprises the following steps: 1) removing fishes; 2) adding silicate compound aqueous solution; 3) planting various emergent aquatic plants in a target water area; 4) planting various floating-leaf plants in a target water area; 5) constructing submerged plant communities in a target water body area; 6) preliminary construction engineering of fish population structure: performing stocking on a target water area to control algae and trash fish; 7) selecting benthonic animals for a target water area, and selecting water surfaces of the target water area for manual throwing; 8) feeding herbivorous control fishes to realize basic control on submerged plants; 9) throwing mandarin fish and/or culter alburnus. The invention has small investment and quick effect and has a long-acting working basis; 2. the environment is not polluted, the environment is friendly, and the product can be used for a long time; 3. the application range is wide, and the method can be applied to ponds, lakes, landscape water bodies, reservoirs and the like without the limitation of water areas.

Description

Treatment method of water ecosystem aiming at eutrophic water body

Technical Field

The invention relates to the technical field of environmental protection, in particular to a method for treating an aquatic ecosystem aiming at eutrophic water. It is suitable for water bodies such as ponds, lakes, rivers, reservoirs and the like in cities and villages threatened by eutrophication.

Background

In recent years, due to the rapid development of social economy, the strength of artificially improving nature is increased, the problem of eutrophication of lakes in China is becoming more and more serious, so that industrial, agricultural and domestic water in various lake coastal areas is difficult, and the economic development and social stability are seriously influenced.

Eutrophication is a phenomenon describing water environment deterioration caused by abnormal proliferation of some phytoplankton due to overnutrition in a water body, and originally means a natural phenomenon which is irreversible for a long time in an ecological evolution process, but at present, the phenomenon that the water body deterioration is caused by large abnormal proliferation of algae due to abnormal increase of nitrogen and phosphorus in lakes caused by human activities is generally referred to. Wherein the water bloom is a typical characteristic of lake eutrophication (standard of the water bloom, the chlorophyll a concentration in a water body is more than or equal to 10 mu g/L or the algae cells reach 1.5 multiplied by 107 cells/L), and the water surface is in abnormal water color such as green, red, brown and the like due to outbreak propagation of the algae. The fresh water phytoplankton variety initiating algal bloom is many, and generally mainly comprises: cyanobacteria bloom is typically expressed in the summer and autumn where water temperature is high, such as cyanobacteria (Cyanophyta), dinoflagellate (Pyrrophyta), diatom (Bacillariophyta), chlorella (Chlorophyta), and Euglenophyta (Euglenophyta).

When the blue-green algae bloom occurs, thick blue-green lake indigo is formed on the water surface, and is accumulated in large quantity even on the bank, so that the blue-green algae can emit unpleasant smell, the transparency of the water body is reduced, the blue-green algae is propagated in large quantity to release algae toxin, dissolved oxygen in the water body is consumed in large quantity, aquatic organisms are suffocated and die, the water quality of water supply is influenced, the water production cost is increased, and the influence on water ecology and fishery is large.

Currently, many countermeasures have been made for the control of eutrophication, summarized as follows:

(1) controlling the input of exogenous nutrient substances. Mainly establishes the discharge standard of nutrient substances and the water quality standard, implements total amount control according to the phosphorus content of the lake water environment, implements sewage interception engineering or draws and discharges pollution sources.

(2) Reduce the load of endogenous nutrients. Mainly comprising ecological restoration measures, engineering measures, chemical methods and the like.

(3) Removing the nutrient substances in the sewage. Mainly comprises a ferric salt coagulation sedimentation method, an aluminum ion exchange method, lime coagulation and an ammonia stripping method.

(4) Pollution control and water quality improvement. Mainly comprises the treatment of external environment, including cutting off the sewage or removing pollutants and nutrients in the sewage; there is also homeostasis, i.e., the amount of endogenous pollutants and nutrients is reduced.

Generally speaking, the method plays a significant role in preventing and controlling the lake eutrophication, and the application of ecological restoration measures is greatly popularized and applied in recent years, which plays an important role in controlling and controlling the lake eutrophication.

The ecological restoration measures mainly comprise:

(1) an aquatic plant community construction method. Mainly comprises the construction of submerged plant, emergent aquatic plant and floating-leaf plant communities. Due to eutrophication of the water body, the optical performance of the water body is reduced, so that the submerged plants are difficult to recover directly, and the implementation effect is different, which becomes a difficult problem.

(2) A fish population structure adjusting and controlling method. The abundance of large zooplankton is indirectly increased by classical biological manipulation (predatory), i.e. by increasing predatory fish in a body of water to reduce filter-feeding fish species. In addition, there is a biological manipulation model called non-classical biological manipulation (non-classical biological manipulation) for increasing silver carp and bighead carp filter feeding fish and reducing grazing fish to directly graze cyanobacterial bloom.

(3) A benthonic animal community construction method. Mainly improves the water environment through the throwing of the snail, the mussel and the corbicula and the biological filtration.

Generally speaking, the ecological measures have obvious effect on preventing and controlling water eutrophication, but the water eutrophication is propagated excessively to algae, the substrate has anaerobic environment, a great amount of aquatic animals are reduced, the water supply is seriously influenced, the landscape value is weakened, and the final effect of the ecological restoration measures is different due to the complexity of a water ecological system. Therefore, the prevention and control of water eutrophication is still a general problem, and a control method with obvious effect, low investment, convenient control and repeatability is urgently needed.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a treatment method of an aquatic ecosystem aiming at eutrophic water body, which has obvious effect and low investment.

In order to solve the technical problems, the invention adopts the technical scheme that:

a method for treating an aquatic ecosystem aiming at an eutrophic water body comprises the following steps: 1) removing fishes; 2) adding silicate compound aqueous solution; 3) planting various emergent aquatic plants in a target water area; 4) planting various floating-leaf plants in a target water area; 5) constructing submerged plant communities in a target water body area; 6) performing stocking on a target water area to control algae and trash fish; 7) selecting benthonic animals for a target water area, and selecting water surfaces of the target water area for manual throwing; 8) feeding herbivorous control fishes to realize basic control on submerged plants; 9) throwing mandarin fish and/or culter alburnus.

Preferably, a step of adding the diatomite-microorganism composite microbial inoculum when the transparency of the target water body is less than or equal to 40cm is further included between the step 2) and the step 3).

Preferably, a step of putting dace to control periphyton is further included between the step 5) and the step 6).

Preferably, the benthonic animal in step 7) is a snail, mussel or clam.

Preferably, the herbivorous control fish in step 8) is bream or grass carp.

Preferably, a step of putting rotifers to control abnormal proliferation of diatoms and a step of putting medaka to control wigglers are further included between the step 7) and the step 8).

Preferably, a step of feeding loaches to reduce organic debris and a step of feeding black carps to control abnormal proliferation of the benthonic animals is further included between the step 8) and the step 9).

Preferably, the silicate compound aqueous solution in the step 2) is an aqueous solution of sodium metasilicate, copper sulfate, potassium dihydrogen phosphate and quick lime, and the mass ratio of the sodium metasilicate to the copper sulfate to the potassium dihydrogen phosphate to the quick lime is 5:2:1: 2.

Preferably, after the silicate compound aqueous solution is added to the target water body, the content of metasilicic acid in the target water body is more than or equal to 12.90 mg/L.

Preferably, the fish removed in step 1) is grass carp, black carp, crucian carp, pseudorasbora parva, bitterling, white striped fish, fantail or mosquito-eating fish.

Preferably, the submerged plants in the step 5) are mainly completed in the stage 2, pioneer seeds are planted in the stage 1, and group seeds are established in the stage 2.

According to the characteristics of systematicness, complexity, long-range property and nonlinearity of the water ecosystem, the method for preventing and treating eutrophication of the water body has long and unstable effect, needs to reasonably arrange treatment measures according to the characteristics of the water ecosystem and advance step by step, furthest reflects the effect of the water body eutrophication prevention and treatment measures, can radically reverse the water quality deterioration trend within 3 years, promotes the realization of the water body function target, and provides a brand-new system engineering mode for treating the water body eutrophication.

Compared with the prior art, the invention has the following beneficial effects:

1. the investment is small, the effect is quick, and the long-acting use work foundation is achieved;

2. the environment is not polluted, the environment is friendly, and the product can be used for a long time;

3. the application range is wide, and the method can be applied to ponds, lakes, landscape water bodies, reservoirs and the like without the limitation of water areas.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following detailed description of the present invention is provided in connection with specific embodiments.

The invention provides a method for treating an aquatic ecosystem aiming at eutrophic water, which comprises the following steps:

step 1, fish engineering removal. The method is characterized in that fish removal is carried out on target water bodies, mainly grass carp and black carp, and various small and medium-sized trash fishes which have interference effect on aquatic plant recovery, and methods such as a water level reduction dry lake method, a quick lime method, a bleaching powder (essence) method and a conventional trawl method are adopted. If the target is not a closed water body, a fish (sewage) blocking fence is arranged at the water inlet and the water outlet after the fish removing engineering is finished. The small and medium-sized trash fish refers to crucian, carp, pseudorasbora parva, bitterling fish, white striped fish, dragonfish or mosquito-eating fish.

And 2, algae habitat regulating engineering. And adding a silicate compound aqueous solution into the target water body by a water pump through a ship, wherein the silicate compound aqueous solution is an aqueous solution of sodium metasilicate, copper sulfate, potassium dihydrogen phosphate and quicklime, and the mass ratio of sodium metasilicate to copper sulfate to potassium dihydrogen phosphate to quicklime is 5:2:1: 2. After the water body is put into the water body, the metasilicic acid content in the target water body is more than or equal to 12.90mg/L, and the water body habitat is transited from a blue algae type with high nitrogen, high phosphorus and low silicon which is suitable for the growth of the blue algae to a diatom type with high nitrogen, high phosphorus and high silicon.

And step 3, transparency improving engineering. The microbial agent is added by adopting an intensified direct adding method, namely, a diatomite-microbial compound microbial agent (the mass ratio of diatomite to microbial agent is 1:1) and water in a target water body are prepared into a dissolved solution (the preparation ratio is 1:3), the microbial agent is added by adopting a full-water-area spraying mode, the spraying amount is properly increased in a severe pollution area, the using amount is 45kg/ha, and a basic habitat is created for the recovery of aquatic plants. In this embodiment, the microbial composite inoculant is determined according to actual needs, and can be purchased in the market, for example, a microbial water purification agent for nitrogen and phosphorus.

And 4, constructing an emergent aquatic plant community. Emergent aquatic plants are mainly planted in a connected mode, are planted in a dotted cluster mode, are assisted by the dotted cluster, are combined to form a landscape outline shape, and are planted in a water-land staggered area with a small water level amplitude (within 80 cm). The planting area is 30-50% of the area of the shoreline of the target water area. The main planting varieties are: zizania (Zizaniaacanduloba), Eleocharis tuberosa (Eleocharis tuberosa), candelilla (Typha angustifolia), Acorus calamus (Acorusaglamus L.), Acorus gramineus (Acorus tarariii Schitt.), edible tulip (Sagittaria pygmaeaMiq.), Lythra glehnia (Lythrum salicia L.), Nuphar pumila (Nuphar pumllium (Timm.) DC.).

And 5, constructing a floating-leaf plant community. The floating-leaf plants are mainly planted in a connected mode, are planted in a dotted cluster mode, are combined to form a landscape outline shape, and are planted in a water area with small wind waves, and the planting area of the floating-leaf plants is 1% -3% of the target water area. The main planting varieties are: water lily (Nymphaeatetragona G.), Xinjiang nut (Nymphoides peltatum), and Gorgon fruit (Euryale ferox).

And 6, constructing a submerged plant community. According to the pollution degree of target water area, submerged plant is mainly divided into 2 stages to be completed, pioneer species are planted at 1 st stage, mainly potamogeton crispus L, golden fish algae (Ceratophyllumdemersum), Myriophyllum spicatum L and so on, mechanical or artificial salvage is carried out after planting is completed until the coverage area reaches more than 20% -30% of the total area of target water area in the next year, and the submerged plant is salvaged out of water, dewatered and innocent treatment is carried out, so that pollutants are discharged out of lake. Planting and breeding at the 2 nd stage, mainly removing submerged plants planted at the 1 st stage, planting Potamogeton maackianus A. Benn.), herba Swertiae Dilutae (Lour.) Hara, Hydrilla verticillata (L.f.) Royle, etc., and performing routine maintenance and management after planting. The total submerged plant area is maintained at 20-30% of the total area of the target water area.

And 7, periphyton control engineering. In the initial improvement stage of the water quality of a target water area, the amount of the periphyton algae grows, the water quality is poor, the controlled fish dace is put in, and effective control on the periphyton algae is realized through putting in and harvesting. The dace is not cold-resistant, has strong stain resistance and rapid growth, is suitable for controlling algae in an environment with poor water quality, and the feeding specification and density are detailed in table 1.

TABLE 1 dace Specification and Density for feeding

Variety of (IV) C	Specification of	Density of
			Dace	50-100 g/tail	15000 tail/ha

And 8, primarily constructing a fish population structure project. The stocking of fish should be carried out in 2 stages after the submerged plant is recovered. Feeding filter-feeding silver carp, bighead carp and carnivorous snakehead in the early period. Controlling the outbreak of the cyanobacterial bloom through the descending effect of silver carps and bighead carps on phytoplankton ingestion; the small trash fish is controlled by the snakeheads. Triploid is dosed and specification and density are detailed in table 2.

TABLE 2 Fish population Structure Regulation engineering-breed, quantity and Density

Variety of (IV) C	Specification of	Density of	Remarks for note
				Silver carp	150-200 g/tail	900 tail/ha	Put in earlier stage
Bighead carp	150-200 g/tail	300 tail/ha	Put in earlier stage
				Snakehead fish	100-200 g/tail	30/ha	Later-stage delivery

And 9, constructing a benthonic animal community. Benthonic animals such as snail, mussel, corbicula and the like are selected in a target water area, and the benthonic animals are selected on the water surface of the target water area to be manually thrown in, wherein the throwing ratio is shown in the following table 2. In order to promote self-renewal of benthonic animal communities in target water areas, a certain amount of rhodeus and pelteobagrus fulvidraco are required to be thrown, diploid fish can be thrown, and the throwing specifications and the number are shown in tables 3 and 4.

TABLE 3 zoobenthos community construction engineering scale

Stocking variety	Specification of	Throwing ratio (kg/ha)
			Screw thread	River snail in local lake	20
Mussel	Local lake mussel	20
			Corbicula fluminea	Corbicula fluminea	10

Specification and density are put in to table 4 bitterling

Variety of (IV) C	Specification of	Density of
			Bitterling	10 to 20 g/tail	400 tail/ha
Yellow catfish	50-100 g/tail	60 tail/ha

And step 10, controlling multiple growth of the periphytic algae. After the water quality is improved, the catfishes can be thrown (the general names of xenocypris davidi bleekers, plagiognathops microlepis and silver catfishes), the catfishes are cold-resistant but weak in pollution resistance, and can scrape the submerged periphytic algae (including large filamentous algae, periphytic diatoms, green algae and the like) in the natural water body and also eat organic substances in the bottom mud. And 3, putting the catfish into the diploid fish for 3 months, wherein the putting time is not longer than 3 middle-of-month.

TABLE 5 Specifications and Density of Xenocypris davidi feeding

Variety of (IV) C	Specification of	Density of
			Xenocypris davidi	50-100 g/tail	22500 tail/ha

And step 11, controlling multiple diatoms. When the water quality of the target water body is improved for a period of time, diatoms are often abnormally proliferated to influence the water quality and landscape, and biological control, namely rotifer throwing, is carried out according to the situation, which is detailed in table 6.

TABLE 6 Specifications and Density for Trypanosoma feeding

Variety of (IV) C	Specification of	Density of
			Rotifer worm	Resting eggs or living bodies of rotifers	350000-500000 heads/L

Step 12, controlling multiple mosquitoes (wigglers). After the submerged plants in the target water body recover, mosquitoes (wigglers) often breed to bring the problem of environmental sanitation, a control project, namely putting medaka in the target water body is needed, diploids can be put in the target water body, and the putting specification and the number are shown in a table 7.

TABLE 7 medaka Release Specification and Density

Variety of (IV) C	Specification of	Density of
			Medaka (medaka)	5 to 10 g/tail	1000 tail/ha

And step 13, controlling multiple submerged plants. With the continuous improvement and stability of the target water quality, submerged plants are likely to grow in large quantities, which exceed 30% of the total area of the target water body, and at the moment, effective management and control are needed, a certain amount of triploid bream (perianthus pekinensis and megalobrama amblycephala) can be put in, and the putting specification and the amount are shown in table 8.

Table 8 specification and density of bream feed

Variety of (IV) C	Specification of	Density of	Remarks for note
				Bream fish	100-200 g/tail	60 tail/ha	Later-stage delivery

And 14, organic debris reduction engineering. When submerged plants, grazing fishes and benthonic animals are successfully settled, grass carps have high grazing amount due to the feeding preference, so that the biomass of the submerged plants is inevitably reduced, and the community structure of the submerged plants is changed. However, the water transparency is affected due to the significant increase of plant debris and fish feces on the water bottom, and necessary measures are needed. Therefore, a certain amount of loaches and diploids need to be put in, and the putting specifications and the number are shown in the following table 9.

TABLE 9 loach Specification and Density

Variety of (IV) C	Delivery specification	Throwing density
			Loach	20 to 30 g/tail	50kg/ha

And step 15, benthonic animal abnormal proliferation control engineering. After successful settlement, a large amount of snails can proliferate, and directly graze the branches and leaves of the plants, so that the growth of submerged plants can be inhibited. The snails eat the sprouts and the young leaves of the submerged plants, so that the photosynthesis of the submerged plants is reduced, and the biomass is slowly increased. Therefore, a certain amount of triploid black carp is required to be added, and the adding specification and amount are shown in the following table 10.

TABLE 10 Black carp stocking specification and density

Stocking variety	Stocking specification	Throwing density
			Black carp	500-1000 g/tail	5-8 tails/ha

And step 16, fish population structure adjustment and optimization engineering. With the improvement of the water quality of the target water body, the settlement and the propagation of submerged plants, the population quantity of fishes is continuously increased, especially, small and medium-sized trash fishes can form certain pressure and interference on zooplankton and aquatic plants, the population structure of the fishes also needs to be adjusted and optimized, a certain quantity of diploid carnivorous fishes, namely mandarin fishes and culter alburnus, are put in, and the putting specification and the quantity are shown in the following table 11.

TABLE 11 Fish population structure adjustment and optimization engineering

Variety of (IV) C	Specification of	Density of
			Mandarin fish	100-200 g/tail	100 tail/ha
Erythroculter ilishaeformis	100-200 g/tail	100 tail/ha

The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the protection scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.

Claims (10)

1. A method for treating an aquatic ecosystem aiming at an eutrophic water body is characterized by comprising the following steps:

1) removing fishes; 2) adding silicate compound aqueous solution; 3) planting various emergent aquatic plants in a target water area; 4) planting various floating-leaf plants in a target water area; 5) constructing submerged plant communities in a target water body area; 6) preliminary construction engineering of fish population structure: performing stocking on a target water area to control algae and trash fish; 7) selecting benthonic animals for a target water area, and selecting water surfaces of the target water area for manual throwing; 8) feeding herbivorous control fishes to realize basic control on submerged plants; 9) throwing mandarin fish and/or culter alburnus.

2. The method for remediating an aquatic ecosystem for an eutrophic water body according to claim 1, further comprising the step of feeding dace to control periphyton between the step 5) and the step 6).

3. The method for remediating an aquatic ecosystem for an eutrophic water body according to claim 1, wherein the benthonic animals in the step 7) are snails, clams or clams.

4. The method for remediating an aquatic ecosystem for an eutrophic water body according to claim 1, wherein the herbivorous fish of step 8) is bream or grass carp.

5. The method for aquatic ecosystem of eutrophic water according to claim 1, further comprising the step of putting rotifers to control abnormal proliferation of diatoms and putting medaka to control wigglers between step 7) and step 8).

6. The method as set forth in claim 1, further comprising the steps of cutting down organic debris by loaches and controlling abnormal proliferation of benthonic animals by feeding black carps between the step 8) and the step 9).

7. The method for treating an aquatic ecosystem for an eutrophic water body according to claim 1, wherein the silicate-based composite aqueous solution in the step 2) is an aqueous solution of sodium metasilicate, copper sulfate, monopotassium phosphate and quicklime, and the mass ratio of the sodium metasilicate, the copper sulfate, the monopotassium phosphate and the quicklime is 5:2:1: 2.

8. The method for treating an aquatic ecosystem for an eutrophic water body, according to claim 7, wherein the metasilicic acid content in the target water body is not less than 12.90mg/L after the silicate-based composite aqueous solution is added to the target water body.

9. The method for treating an aquatic ecosystem for eutrophic water of claim 1, wherein the fish removed in step 1) is grass carp, black carp, crucian carp, pseudorasbora parva, bitterling, white striped fish, fantail or mosquito-eating fish.

10. The method for remedying an aquatic ecosystem for an eutrophic water body according to claim 1, wherein the submerged plants in the step 5) are mainly completed in the 2 nd stage, the pioneer species are planted in the 1 st stage, and the colony-forming species are planted in the 2 nd stage.