CN107311314B

CN107311314B - In-situ ecological restoration method for black and odorous riverway

Info

Publication number: CN107311314B
Application number: CN201710545304.XA
Authority: CN
Inventors: 田城德; 陶正; 张文章; 翁晓红
Original assignee: Shanghai Haidian Agricultural Biotechnology Co ltd
Current assignee: Shanghai Haidian Agricultural Biotechnology Co ltd
Priority date: 2017-07-06
Filing date: 2017-07-06
Publication date: 2021-01-12
Anticipated expiration: 2037-07-06
Also published as: CN107311314A

Abstract

The invention discloses an in-situ ecological restoration method for a black and odorous river channel, which comprises the following steps: (1) flushing and turning over target river bottom sludge by using a high-pressure water gun to enable river sludge to be suspended in a water body; (2) in the process of the step (1), microbial preparation is put into the target water body, a water body ecological system is established, pollutants in water are degraded, and sludge reduction is carried out to purify the water quality; (3) the dissolved oxygen content of the water body is increased and organic pollutants are oxidized and reduced by utilizing nano aeration; (4) and (4) after the step (3) is completed for one to two days, arranging a plant floating island on the target water area, wherein the plants on the plant floating island absorb nutrient substances converted by the microorganisms and interact with the photosynthetic function of the microorganisms to establish and maintain the underwater ecological water purification quality. The invention has the advantages of low investment cost, simple operation, convenient maintenance and stable treatment effect, and the ecological system for treating the water area is reliably and durably maintained without disturbing residents, occupying peripheral cultivated land and polluting any risk.

Description

In-situ ecological restoration method for black and odorous riverway

Technical Field

The invention relates to the technical field of river pollution treatment, in particular to an in-situ ecological restoration method for a black and odorous river.

Background

The river sediment is an important component of a river water system ecological system, and the self-cleaning function of the river mainly comes from the functions of dilution, adsorption, microbial degradation and the like. Wherein, the bottom mud adsorption and the microbial degradation are the main forms of the river pollutant conversion reduction, and the bottom mud plays an irreplaceable role in the river self-purification.

A large amount of point source pollution such as industrial wastewater, domestic sewage and the like is discharged; surface runoff, agricultural runoff, dry settlement and wet discharge of atmosphere and the like are polluted and gathered in a large amount; the long-term excessive sewage collection of rain and sewage leads to the sludge deposition of river channels, and the water ecology incurs serious damage. The oxygen supply and consumption mechanism is unbalanced, aerobic microorganism decomposition is dominant, and the aerobic microorganism decomposition is gradually converted into anaerobic microorganism activity, so that the water body loses self-cleaning capability and the river channel is black and smelly.

The river sludge releases a large amount of toxic substances (including harmful gas) while consuming oxygen in the water body in luxury, so that the water body is in a serious anoxic state for a long time, the deteriorated water quality further aggravates the oxygen consumption rate of the river, and the bottom sludge of the river and the primary ecosystem of the water system are thoroughly destroyed. Therefore, the water body is seriously polluted and formed due to vicious circle.

At present, the most common and most simple method for treating the black and odorous river is to dilute and replace a water area with small or local serious pollution by using water with better quality in a larger water system. Such a vicious circle leads to the deterioration of the whole water quality, and even part of the great rivers pollute IV-type water and even V-type water, thus causing water crisis.

The treatment of the sludge adopts a dredging method, but the following problems exist in the behavior:

I. high cost, mechanical dredging 1hm³The sediment needs about $ 9.9 to $ 24.7 ten thousand; dredging too deep will destroy the original ecosystem, and dredging of sediment may remove benthos and destroy the food chain of fish. If the substrate sludge is dredged completely, it may take 2 to 3 years to re-establish the benthic organism community. III, the dredging operation of the small section of the urban river channel is inconvenient for a dredger to carry out the overwater operation. IV, the dredged sediment has large amount, complex pollutant components and high water content and is difficult to treat.

Disclosure of Invention

The invention aims to solve the technical problem of providing an in-situ ecological restoration method for a black and odorous river channel, aiming at solving the technical problem in the existing black and odorous river channel restoration process. The method is based on the principle of inter-restriction of the natural world and ecological rules, and based on the combination of the technologies of the modern microbial technology, the technologies of nano bubbles, ecological floating islands and the like, and the means of oxygen fusion of the water body, establishment of a microbial system and long-term ecological maintenance of the water body are taken to achieve the purposes of gradually reducing the river bottom sludge, restoring the ecological function of the bottom sludge and purifying the black and odorous river water.

The technical problem to be solved by the invention can be realized by the following technical scheme:

a method for in-situ ecological restoration of a black and odorous river comprises the following steps:

(1) using a high-pressure water gun to flush and stir target river sludge so that the river sludge is suspended in a water body, and simultaneously putting a microbial preparation to establish a water body microbial system for biochemically degrading pollutants in the water;

(2) the nano-bubble generator is utilized to release a large amount of nano-scale bubbles into the black and odorous water body of the target river channel, the clustering support force of the nano-bubbles enables organic matters in the black and odorous water body to float and collect on the water surface, and then the organic matters are collected and used as resources for preparing biological organic fertilizer, meanwhile, the dissolved oxygen content of the water body is improved, and partial pollutants in the water are oxidized and reduced;

(3) after the step (2) is completed for one to two days, a plant floating island is arranged on the water area for treating the river channel, and the plants on the plant floating island absorb nutrient substances released by the microbial conversion sludge; simultaneously, the sludge reduction in situ is carried out to purify water quality;

in the above process, the step (2) is carried out until the stage target requirement is reached.

In a preferred embodiment of the present invention, the diameter of the nano-scale bubbles is 0.1-50 um.

In a preferred embodiment of the invention, when the step (3) is carried out, the amount of the water body oxygen dissolved in the river channel is 15-30 mg/L.

In the invention, the microbial preparation is prepared from the following strains in percentage by number of colonies:

in a preferred embodiment of the present invention, in the step (2), the microbial preparation is put into the black and odorous water body of the target river channel, and the usage amount and method thereof are as follows: adding 25 kg of microbial preparation into 250kg of target river water, uniformly mixing, and uniformly putting into a water body.

In a preferred embodiment of the invention, aquatic plants are planted on the plant floating island and carbon fiber microorganism hosts are arranged to ensure the function of a microorganism system to be sustainable and the plants on the floating island grow normally.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following characteristics:

1. the nano-scale bubbles adopted by the invention have small volume and stay in water for a long time. The self-pressurization effect of the micro-nano bubbles can effectively improve the mass transfer efficiency and the dissolved oxygen content of a gas-liquid interface, and microorganisms adopted by the invention can fully perform biological reaction under the condition of high oxygen content of a water body to degrade organic pollutants in water. In addition, the nano-bubbles have high interface electrokinetic potential so that the nano-bubbles have high-efficiency adsorption performance, and the nano-bubbles are gathered into large flocs to float to the water surface by adsorbing fine suspended particulate matters in water, so that the effect of air floatation dialysis is achieved.

2. The microbial preparation is a compound microbial agent which is co-cultured by main functional populations such as photosynthetic bacteria, nitrobacteria and the like and a plurality of synergistic floras such as saccharomycetes, phosphorus-solubilizing bacteria, lactic acid bacteria, azotobacter and the like, and is a beneficial microbial system which is harmless to animals and plants and does not damage the environment. The effective bacterial colony number per milliliter reaches more than 100 hundred million, and under ideal conditions, the unit number can be doubled within 20-30min, the propagation speed of the bacterial colony is greatly higher than that of bacteria causing various problems in sewage or water, a functional microorganism system can be quickly established in the water environment, and the life behaviors of the bacteria causing various problems can be effectively inhibited.

The functional microorganism of the invention utilizes organic substances in target water, especially sludge, to carry out metabolism under the condition of oxygen enrichment, and finally is converted into inorganic harmless substances such as carbon dioxide, water and the like. The method realizes gradual conversion and decomposition of pollutants in the river bottom sludge, thereby achieving the purposes of reducing the sludge in situ, restoring a water body ecological system and maintaining a sustainable and good water body environment.

3. The plant floating island of the invention uses the habit of aquatic plants and is composed of ceramsite with a microporous structure, a microorganism supporter (a special carbon fiber microporous structure), a buoyancy engineering structure and other engineering materials. Cultivate for the plant species and plant the basket, the green iris of planting of chinampa, monkey tail and copper coin grass etc. adopts the mode of water planting, and plant coverage area accounts for 1/5 ~ 1/3 of whole surface of water, because the illumination area of different river courses is different, and green plant lays the area and slightly differs. On one hand, the root system of the floating island plant can absorb nitrogen and phosphorus containing substances released in water by decomposing sludge by microorganisms, and the nitrogen and phosphorus containing substances and the microorganisms form a mutual synergistic effect to jointly degrade nutritive salts in water. And the construction cost is low, and the river landscape can be improved.

The method for in-situ ecological restoration of the black and odorous river inherits the optimal ecological concept, establishes a sound water body ecological system and cultures the self-purification function of the water body. And the water bottom sludge is gradually reduced by decomposing and converting the water bottom sludge by specific microorganisms, so that the sludge is eliminated, the bottom sludge native ecological system is restored, and the ecological environment of hydrodynamic plant growth and multiplication is restored. The invention has the advantages of low investment cost, simple operation, convenient maintenance, stable treatment effect, reliable and durable restored ecological system, no disturbance to the people, no occupation of peripheral cultivated land and no pollution risk.

Detailed Description

The method for in-situ ecological restoration of a black and odorous river channel is used for explaining the restoration process and effect of a certain black and odorous river channel in Shanghai in detail.

The water body of the black and odorous river channel is yellow brown and has foul smell from field observation. The source of pollutants in the water body is disordered discharge of nearby domestic sewage, and through field actual measurement, the water depth is average: 2m, sludge depth: 20-80 cm, visibility: 15cm, water surface area about 470m²The volume of the water body is about: 940m³。

The applicant carries out water quality detection on the water body of the black and odorous river channel, and the result is as follows:

compared with the surface water environmental quality standard (GB 3838-:

the content of dissolved oxygen in the target water body is as follows: 2.50, reaching the standard specified value of V-class water, but lower than the standard specified value of IV-class water:

the COD content of the target water body is as follows: 97.15, which is 2.43 times of the standard specified value of V-class water;

the ammonia nitrogen content of the target water body is as follows: 8.55, which is 4.28 times of the standard specified value of V-class water;

the total phosphorus content of the target water body is as follows: 0.84, which is 2.1 times of the standard specified value of V-class water;

pH of the target water body: 7.52, the water quality standard is met.

And (4) combining the detection results to preliminarily draw the following conclusions: the pollution of the target water body is serious, the dissolved oxygen is low, and COD, ammonia nitrogen and total phosphorus are seriously exceeded.

The results are shown in Table 1.

TABLE 1

The treatment scheme of the black and odorous river channel is as follows:

1. and (4) surveying the pollution source of the river channel, and intercepting the culvert pipe channel connected with the collateral river channel. Taking a water sample when entering the field on the first day, taking the water sample at a position 0.5m below the vertical line of the sampling water surface, sampling and detecting at intervals of four to five days later, and the water body detection result is shown in table 2. According to construction requirements, construction equipment such as a micro-nano bubble generating device, a high-pressure water gun and the like is installed and debugged.

2. The next day, 9: 00-11: 00, 15: 00-17: 00, and performing sludge washing operation. Meanwhile, 25 kg of microbial preparation is mixed with 250kg of target river water and then is put into the water body (the microbial putting is finished before 9 o' clock), and then floating objects are removed.

The microbial agent is prepared from the following strains in percentage by number:

3. during the third day is accomplished to the target, micro-nano bubble generator normally worked, and operating time is 9: 00-11: 00, 13: 00-17: 00, and keeping the fused oxygen amount of the target water body to be 15-30 mg/L. And then, properly adjusting the working time and mode of the micro-nano bubble generator according to the detection result.

Removing suspended particles in the water body by nano aeration. Meanwhile, oxygen is supplied to the long-term low dissolved oxygen water body, so that a good ecological environment is provided for the submerged plants to perform photosynthesis; provides a high dissolved oxygen environment for aerobic microbial engineering floras. The water body particles floated by the high-density micro-nano bubbles contain rich organic matters, and are used as an unavailable raw material for preparing the bio-organic fertilizer, so that the secondary pollution is thoroughly eliminated, and the resource utilization is realized.

4. Laying wet ecological floating islands, wherein the green plants of the floating islands are iris, monkey tail, copper cash grass and the like, the water culture mode is adopted, and the plant coverage area accounts for 1/4 of the whole water surface in the river channel treatment process.

Staged targets

The first stage eliminates the black and odorous target water body and lays a foundation for establishing a superior ecological system (from the third day to the tenth day).

3.5mg/L of dissolved oxygen;

C O D 48.26mg/L；

visibility is 30 cm;

smell value, no abnormal water odor.

In the second stage, a healthy river channel optimum ecological system is established, and the period is three months (counted from the tenth day).

In the stage, on the basis of maintaining the dissolved oxygen in the water body, the floating island plants grow vigorously and fully absorb and convert a large amount of substances such as ammonia nitrogen, phosphorus and the like released by decomposing river bottom sludge by functional microorganisms. And gradually enter the biochemical reduction of the river bottom sludge, thereby avoiding the occupation of the conventional dredging river sludge to the bank farmland and the secondary pollution. The main water project can reach the following aims:

the dissolved oxygen is more than or equal to 6 mg/L;

C O D≤35mg/L；

the visibility is more than or equal to 45 cm;

the sludge is reduced, the assimilation and decomposition of organic substances of the river bottom sludge are basically completed, black substances are eliminated to enable the organic substances to be close to the native color, and the function of the bottom sludge is revived.

Ammonia nitrogen is more than or equal to 1.5mg/L, and enters a stable descending line.

The total phosphorus is more than or equal to 0.2mg/L and enters a stable descending line.

And in the third stage, a river channel excellent ecological system is consolidated and maintained, and the continuous self-cleaning function of the river channel is cultured.

The stage is continued after the second stage, and on the basis of establishing a healthy and perfect ecological system for the river channel and ensuring that no serious exogenous pollution is converged, the initial interception setting of the water system circulation pipeline in the first stage is removed;

two thirds of the amount of the initially arranged floating island is cancelled, and the consumption of the floating island plants to the oxygen of the target water body is reduced. And managing the rest floating island plants to keep the plants in vigorous growth and proper scale for a long time. Establishing a natural water environment which is combined with the submerged plants at the river bottom and is suitable for the propagation and growth of fish, shrimp, snail and other organisms;

the river water system is tracked and detected regularly, active defensive maintenance measures are taken, and main project indexes of the overall water quality of the river reach or are superior to V-type standards:

the dissolved oxygen is more than or equal to 6mg/L (which is the water quality standard of II class);

c, O, D is less than or equal to 20mg/L (is a III-class water quality standard);

the visibility is more than or equal to 50cm (which is the normal water quality standard);

ammonia and nitrogen are more than or equal to 1.5mg/L (which is the IV-V type water quality standard), gradually decrease from the initial value to be lower than the initial value through the peak value, and enter a descending line to be stabilized at more than or equal to 1.5mg/L (because both banks have a certain amount of scattered pollution sources to be converged);

the total phosphorus is more than or equal to 0.2mg/L (which is the IV-V type water quality standard), gradually decreases to be lower than the initial value through the peak value from the initial value, and enters a descending line to be stabilized to be more than or equal to 0.2mg/L (because a certain amount of scattered pollution sources are gathered at both banks).

Ecological, the clean and continuous self-cleaning function of the bottom mud is kept, the native aquatic plants grow well, and the ecological systems of fish, shrimps, snails and the like are perfect.

TABLE 2

Claims

1. The method for ecological restoration of the black and odorous river channel is characterized by comprising the following steps:

(1) flushing and turning over target river bottom sludge by using a high-pressure water gun to enable river sludge to be suspended in a water body;

(2) in the process of the step (1), putting a microbial preparation into a target water body, degrading pollutants in the water body, and establishing a water body ecological system;

(3) releasing a large amount of nano-scale bubbles into a target black and odorous water body by using a micro-nano bubble generator, and collecting suspended matters in the black and odorous water body on the water surface by the cluster supporting force of the nano-bubbles, so that the suspended matters are immediately collected to be used as resources for preparing biological organic fertilizer, and simultaneously, the dissolved oxygen content of the water body is improved, and organic pollutants in the water are oxidized and reduced;

(4) after the step (3) is completed for one to two days, a plant floating island is arranged on the target water area, and plants on the plant floating island absorb nutrient substances converted by microorganisms and interact with the photosynthetic function of the microorganisms to establish and maintain underwater ecology so as to reduce sludge and purify water quality;

in the process, the step (3) is carried out until the stage target requirement is met;

the diameter of the nano-scale bubbles is 0.1-50 um;

when the step (2) is carried out, the dissolved oxygen of the water body in the river channel is controlled to be 15-30 mg/L;

the microbial preparation is prepared from the following strains in percentage by number of colonies:

in the step (1), microbial agents are added into the black and odorous water body of the target river, namely 25 kilograms of microbial agents are added into 200 kilograms of target river water, and the microbial agents are added into the target water body after being uniformly mixed;

planting aquatic plants and arranging carbon fiber microbial hosts on the plant floating island to ensure the function sustainability of a microbial system and the normal growth of the floating island plants;

the aquatic plant is one or the mixture of more than two of iris, monkey tail and copper coin grass.