CN113896394B - Urban river and lake water ecological restoration method based on 'first mud and then water' new restoration mode - Google Patents

Abstract

The invention discloses an urban river and lake water ecological restoration method based on a 'mud first and water second' new restoration mode, which is used for urban river and lake bottom mud in-situ restoration and micro-ecological restoration and comprises the following steps: through SedCaN granule, realize the synchronous reduction of anaerobism bed mud carbon nitrogen sulfur pollutant, later based on the microorganism domestication spreads, the in situ regulation and control bed mud microbial community structure realizes having the construction of oxygen microorganism ecosystem. The river and lake pollution in-situ treatment mode and method provided by the invention have the advantages of low energy consumption, low cost, high efficiency, comprehensiveness and safety, and can realize the in-situ treatment target of construction of a water body-sediment healthy ecological system and cooperative reduction of pollutants. The oxygen consumption pollution of sulfide of the bottom sludge and the like can be removed within 15 days, the black and odorous bottom sludge is basically eliminated, the technical bottleneck that the aerobic process is difficult to quickly recover the natural environment of the polluted bottom sludge is solved, the construction period is shortened by more than 30 days, and meanwhile, the cost can be saved by more than 40-50% compared with a dredging scheme.

Description

Urban river and lake water ecological restoration method based on 'first mud and then water' new restoration mode

Technical Field

The invention relates to the technical field of environmental engineering, in particular to an urban river and lake pollution treatment method based on a 'sludge before water' new remediation mode, which is used for treating black and odorous bottom sludge of a river channel, purifying water and reconstructing a microbial ecosystem.

Background

At present, the urban rivers and lakes generally have the problem of bottom mud pollution, and organic matters, nitrogen, sulfur and other substances released by heavily polluted bottom mud can seriously damage the ecological environment of urban water. Considering that certain pollutants exceeding the load capacity of rivers and lakes enter urban river channels after standard reaching treatment, simultaneously, a large amount of non-point source solid wastes are converged into the urban river along with rainwater runoff, and part of pollutants are finally stored in bottom mud through precipitation and particle adsorption to form potential endogenous pollution. At present, the treatment of bottom mud of rivers and lakes in cities in China can be divided into ex-situ treatment and in-situ treatment technologies, and certain effect is achieved. The ex-situ treatment technology mainly comprises environment-friendly dredging and sediment disposal, but the dredging sediment engineering quantity is large, the drying field is large, and the problems of river and lake stirring and secondary pollution are easily caused. The in-situ ecological restoration technology is a main measure in the bottom sludge treatment process in China, pollutants can be treated in situ through biological life metabolic activity, so that the concentrations of the pollutants such as carbon, nitrogen, sulfur and the like in the bottom sludge and the overlying water body are reduced, but the pollution treatment period is long, and the effect is slow, so that the method is a difficult point in the technical application.

The traditional urban river and lake black and odorous bottom sediment treatment generally adopts an aeration reoxygenation and exogenous functional bacteria repairing mode or a bottom sediment desilting process. The former is difficult to infiltrate into a mud-water interface due to dissolved oxygen, the biological oxidation is limited on the surface layer of the bottom mud, the treatment efficiency is low, and the risk of foreign organisms is easily caused. The latter has the disadvantages of high investment, high requirements on construction conditions, large secondary risk and the like.

At present, river sediment treatment is commonly found in a conventional aeration reoxygenation technology, for example, Chinese patent application CN112979116A discloses a river sediment ammonia nitrogen treatment method, which comprises the steps of installing a cutoff plate in a river channel to divide the river channel into a plurality of treatment areas, installing an aeration pipe in a river channel treatment area, and increasing the degradation efficiency of ammonia nitrogen in river sediment by adding certain types of nitrobacteria.

In addition, for the removal of carbon, nitrogen and sulfur from the bottom sludge, a conventional exogenous bacteria adding technology is generally used, for example, the Chinese patent application CN111087085A discloses a method for in-situ remediation of the bottom sludge of black and odorous water body.

At present, a method for in-situ remediation and microecological reconstruction of river sludge is still needed to solve the problems that the water quality of urban black and odorous riverways cannot be rapidly improved and the recovery time of ecological systems at the bottoms of the riverways is long in the prior art.

Disclosure of Invention

Aiming at partial technical problems in the prior art, the invention provides a novel repair mode for strengthening 'sludge before water' in-situ treatment of bottom sludge of rivers and lakes in cities, and the method firstly utilizes an 'anaerobic bottom sludge carbon nitrogen sulfur pollutant synchronous removal technology' to strengthen and reduce the concentration of bottom sludge pollutants and restore the natural reoxygenation environment of the bottoms of rivers and lakes. Secondly, native water purification functional microorganisms are enriched in situ through a 'functional microorganism domestication and dissemination technology', a benign microorganism ecosystem at the bottom of a river or lake is reconstructed, and natural purification capacity is recovered rapidly, so that water quality is improved, and the water environment and human living environment of the river or lake are obviously improved. Specifically, the present invention includes the following.

The invention provides a town river and lake water ecological restoration method based on a 'first mud and then water' new restoration mode, which is used for town river and lake bottom mud in-situ restoration and micro-ecological reconstruction and at least comprises the following steps:

s1, by in-situ denitrification biological enhancement of polluted bottom mud, oxygen-consuming substances on the interface of muddy water are efficiently removed in an anaerobic environment, and black and odorous bottom mud is quickly eliminated, so that favorable conditions are created for recovering the aerobic environment of a water body;

s2, activating aerobic active functional flora, recovering the pollution purification process including natural reoxygenation and aerobic reaction, further eliminating pollutants in all directions, and guiding the reconstructed mud-water aerobic microorganism healthy ecological system.

According to the ecological restoration method for urban river and lake water based on the 'first-mud-then-water' new restoration mode in the first aspect of the invention, preferably, the step S1 includes contacting SedCaN particles with the polluted bottom mud, so as to synchronously reduce carbon, nitrogen and sulfur pollutants in the anaerobic bottom mud.

According to the ecological restoration method for urban river and lake water based on the 'mud-first-water-later' new restoration mode in the first aspect of the invention, preferably, the SedCaN particles are prepared by the following method:

(1) directionally domesticating and enriching indigenous microorganism denitrifying functional flora by using a denitrifying liquid culture medium, and air-drying to obtain a microorganism dormancy body to prepare a microbial agent;

(2) mixing the microbial agent with nitrate to obtain a mixture;

(3) the SedCaN particles are prepared by mixing the mixture with a binder and sodium alginate.

According to the ecological restoration method for the urban river and lake water based on the 'first-mud-then-water' new restoration mode in the first aspect of the invention, preferably, the nitrate comprises calcium nitrate, sodium nitrate, potassium nitrate or a mixture thereof.

According to the ecological restoration method for the urban river and lake water based on the 'first-mud-then-water' new restoration mode, in the first aspect of the invention, the mass ratio of the microbial agent to the nitrate is preferably 1:5-1:3, and is further preferably 1:4.5-1: 3.5.

According to the ecological restoration method for the urban river and lake water based on the 'mud-first-water' new restoration mode in the first aspect of the invention, preferably, the binder is polyvinyl alcohol.

According to the ecological restoration method for the urban river and lake water based on the 'first-mud-then-water' new restoration mode, in the first aspect of the invention, the mass ratio of the mixture, the adhesive and the sodium alginate is preferably 6-20:1:1, more preferably 7-18:1:1, and even more preferably 8-16:1: 1.

According to the ecological restoration method for the urban river and lake water based on the 'first-mud-then-water' new restoration mode, in the first aspect of the invention, preferably, the step S2 includes using a microorganism domestication scattering device, so as to realize the construction of an aerobic microorganism ecosystem, wherein the device includes a multi-gallery body, a mud water pump, a sludge pump, a guide wall and an aeration device.

According to the ecological restoration method for the urban river and lake water based on the 'first-mud-then-water' new restoration mode in the first aspect of the invention, preferably, the multi-corridor main body comprises a mud-water separation unit, a directional domestication unit and a strain broadcasting unit.

According to the method for ecological restoration of town river and lake water based on the 'first mud and then water' new restoration mode in the first aspect of the invention, preferably, the step S2 includes:

a. continuously collecting the floating mud on the surface layer of the polluted river or lake, primarily screening the floating mud, then entering a mud-water separation unit, arranging a baffle plate assembly by using a shallow sedimentation principle, rapidly settling the floating mud under the action of centrifugal force and gravity, and collecting and obtaining high-concentration sludge;

b. adding high-concentration sludge and a microorganism enrichment culture solution into the directional domestication unit, regulating and controlling the directional domestication unit, and quickly enriching aerobic indigenous microorganisms to obtain a large amount of active functional zoogloea; wherein the weight-volume ratio of the high-concentration sludge to the microorganism enrichment culture solution is 1:1-1:10, preferably 1:2-1: 9. Further preferably, the weight to volume ratio is 1:3 to 1: 8.

c. Collecting the zoogloea rich in the active function, and further culturing in the strain broadcasting unit to improve the environmental adaptability and stability of the functional bacteria;

d. according to the water body and the surface layer sediment pollutant concentration, the aerobic active zoogloea feeding amount is adjusted, the continuous broadcasting is carried out, and the microorganism condition for long-term water quality purification is provided.

Preferably, in the step b, the method comprises the steps of regulating and controlling the carbon-nitrogen ratio of the culture solution in the directional domestication unit, and matching an aeration system, a temperature control system, stirring conditions and the like.

The invention provides an aerobic domestication and broadcasting system of an in-situ remediation microbial inoculum for polluted bottom sludge of rivers and lakes in cities and towns.

Compared with the traditional mode of 'treating water and not treating mud', the mode of 'treating mud first and then water' provided by the invention better follows the natural law, has the advantages of low energy consumption, low cost, higher efficiency, more comprehensiveness and higher safety, realizes the in-situ treatment target of the construction of a water body-sediment healthy ecological system and the cooperative reduction of pollutants, and is a novel mode for treating and restoring the water environment of rivers and lakes. The beneficial effects of the invention are mainly embodied in the following three aspects:

(1) the synchronous reduction of bottom sludge pollutants in an anaerobic environment is promoted in an economic and effective mode.

The SedCaN particles adopted by the invention are all natural and degradable materials, so that secondary pollution is not caused, and the cost is low. Through technical implementation, 95% of oxygen consumption pollution such as sulfide of the bottom sludge can be removed within 15 days, black and odorous bottom sludge is basically eliminated, the technical bottleneck that the aerobic process is difficult to quickly recover the natural environment of the polluted bottom sludge is solved, and the construction period is shortened by more than 30 days.

(2) The water quality of rivers and lakes is continuously improved and the ecological quality of the water environment is improved.

Through the anaerobic bottom mud remediation technology, the endogenous pollution load is reduced, and the limitation that the traditional aeration dissolved oxygen is difficult to permeate into a mud-water interface and the biological oxidation is limited on the surface of the bottom mud is solved. Through acclimatization and broadcast sowing of aerobic microorganisms, the quantity of the zoogloea with the water purifying function of the water body is increased, the flocculation adsorption performance of the zoogloea is improved, water pollutants can be vertically captured and degraded in the process of diffusion along with water flow, and the water environment quality is improved.

(3) The reconstruction of the bottom mud healthy microorganism ecosystem in the aerobic environment is accelerated.

The strain resource comes from the surface layer floating mud of the restoration object, contains indigenous microorganisms beneficial to water environment restoration, and has stronger adaptability and stability and small biological risk compared with an external functional microbial inoculum. Through the precipitation collection, the directional domestication and the river broadcasting of the multi-gallery aerobic functional microorganism enrichment equipment, an 'activated sludge layer' can be formed on the surface layer of the bottom sludge within 10 days and the reconstructed 'sludge-water' microorganism is guided to be healthy and ecological, and compared with a dredging scheme, the cost can be saved by more than 40-50%.

Drawings

FIG. 1 is NO ₃ ^- The electron acceptor stimulates the carbon-sulfur contaminant to synchronously remove the microbial mechanism.

FIG. 2 is a multi-gallery aerobic functional microorganism directional enrichment mechanism.

Fig. 3 is a schematic diagram of a multi-gallery functional microbial flora domestication and broadcasting device, which comprises a multi-gallery main body 1, a sludge-water separation unit 11, a directional domestication unit 12, a strain broadcasting unit 13, a sludge pump 2, a sludge pump 3, a guide wall 4, an aeration pump 5 and accessories thereof, a nutrient solution dosing system 6 and a zoogloea broadcasting device 7, wherein the accessories comprise an air flow meter 51 and an aeration disc 52.

FIG. 4 is a mud-water effect diagram before and after in-situ bioremediation of polluted bottom mud of a river channel A in an anaerobic environment: the bottom mud is shown as A in the figure, and the overlying water body is shown as B in the figure.

FIG. 5 shows the apparent characteristic changes of the bottom sludge before and after the in-situ anaerobic bioremediation in the sludge-water treatment mode: in the figure A represents the technique before use; b represents sampling using 20 days; c represents using 27 days sampling; d indicates 34 days of sampling were used.

Fig. 6 is the change of the surface appearance characteristics of the overlying water before and after the in-situ aerobic bacterial acclimation and broadcasting under the treatment mode of mud first and water second: A. before the technology is used; B. after the technology is used.

FIG. 7 shows the ammonia nitrogen index changes of the upper water at different periods in the treatment mode of mud first and water second: a is the anaerobic bioremediation period; b is the acclimation and broadcasting period of the aerobic functional bacteria.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that the upper and lower limits of the range, and each intervening value therebetween, is specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only the preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control. Unless otherwise indicated, "%" is percent by weight.

Urban river and lake water ecological restoration method based on 'first mud and then water' restoration mode

The method is different from the prior art, particularly the bottom sludge treatment mode is different from the traditional river treatment process, the inventor surprisingly discovers that the synchronous reduction of carbon, nitrogen and sulfur pollutants in the heavily polluted bottom sludge can be realized through an in-situ bioremediation new mode of firstly treating the sludge and then treating the water, particularly through an anaerobic bottom sludge carbon, nitrogen and sulfur pollutant synchronous removal technology and an aerobic functional microorganism domestication and scattering technology, so that the technical problem in the conventional aeration reoxygenation is solved.

S1, anaerobic bottom sludge carbon nitrogen sulfur pollutant synchronous reduction technology based on SedCaN particle new material

Step S1 of the present invention is based on the following technical principle: the polluted bottom sludge of the rivers and the lakes is in an anaerobic/anoxic state for a long time, and indigenous microorganisms mainly comprise anaerobic metabolic bacteria. The polluted bottom sediment presents a spatial distribution rule of 'surface mixed layer-nitrate nitrogen accumulation layer-denitrification accelerating layer-ammonium nitrogen accumulation layer' from top to bottom in the vertical direction. By using this niche characteristic, by hypoxia (NO) ₃ ^- ) Biostimulation method for directionally enriching functional denitrifying microorganisms and enhancing autotrophic denitrification (NO) ₃ ^- +S ^2- →N ₂ +SO ₄ ^2- ) And heterotrophic denitrification (NO) ₃ ^- +OM→N ₂ +CO ₂ ) Thereby realizing the synchronous removal of carbon, nitrogen and sulfur and strengthening the blackening and odor-causing sulfurThe mechanism for removing the compounds and organic pollutants is shown in figure 1. NO contained in the SedCaN particles of the present invention ₃ ^- The components of the composition are that the growth of denitrifying functional bacteria is biologically stimulated, and sulfur autotrophic denitrifying bacteria are utilized to oxidize FeS/H ₂ S is SO ₄ ^2- Oxidizing organic matter to CO by heterotrophic denitrifying bacteria ₂ The synchronous removal of carbon, nitrogen and sulfur is realized, and the mechanism is different from that of the traditional aeration method.

S2, construction of aerobic microorganism ecosystem based on microorganism domestication and dissemination technology

In the method, the construction technology of the microbial ecosystem is different from the conventional exogenous bacteria feeding technology. Through the microorganism domestication and scattering equipment, the functions of 'continuous culture-continuous reinforcement' of indigenous microorganisms are realized by 'mud-water separation-directional domestication-regular scattering', and foreign species invasion caused by the addition of an exogenous microbial agent is avoided by in-situ regulation and control of a bottom mud microbial community structure.

Step S2 of the present invention is based on the following technical principle: the surface layer bottom mud and the overlying water body of the benign water ecosystem are in an aerobic state, and the metabolism of microorganisms is mainly aerobic respiration. By aerobic (O) ₂ ) The biological stimulation method is used for directionally enhancing the degradation of organic matters and enriching functional floras such as aerobic ammonia oxidation and the like, and is shown in figure 2. The method comprises the steps of obtaining indigenous microorganism active inoculation mud from bottom mud of rivers and lakes, directionally enriching aerobic functional bacteria through the external microorganism acclimation system, putting active sludge into the bottoms of the rivers and lakes through the broadcasting unit, regulating and improving a bottom mud microorganism ecosystem, and providing necessary biological conditions for continuously improving water quality.

The device comprises a multi-gallery functional microbial flora domesticating and broadcasting device, which comprises a multi-gallery main body, a mud water pump, a sludge pump, a guide wall and an aeration device. Wherein, the multi-gallery main body comprises a mud-water separation unit, a directional domestication unit and a strain broadcasting unit which are arranged in sequence. Preferably, the aeration device further comprises an aeration pump, an air flow meter and an aeration disc. Herein, the sludge pump, the aeration pump, the air flow meter, and the aeration tray may use apparatuses known in the art. The mud pump is arranged in the mud-water separation unit, and the aeration pump is arranged in the directional domestication unit and the strain broadcasting unit. The guide walls are positioned on the mud-water separation unit, the directional domestication unit and the strain broadcasting unit so as to enhance the water body flow and reduce dead angles of a flow field in the units. Preferably, the apparatus of the present invention comprises a nutrient solution dosing system 6 provided to the directional acclimation unit 12 and a zoogloea spreading apparatus 7 provided to the spawn spreading unit 13.

In step b of the invention, the volume ratio of the mud to the water entering the directional domestication unit is 1:10-60, and preferably 1: 20-50. The step b of the invention further comprises the step of regulating the carbon nitrogen phosphorus ratio of the culture solution, preferably, the nitrogen source is added to ensure that the ammonia concentration is 10-35mg/L, and also preferably 20-25mg/L, and the carbon nitrogen phosphorus ratio and the aeration intensity are regulated to ensure that the dissolved oxygen is 3-5 mg/L.

Preferably, the carbon source and the nitrogen source of the directional domestication unit and the strain broadcasting unit are regulated and controlled, so that the carbon concentration is gradually reduced from 100mg/L and the ammonia nitrogen concentration is gradually reduced from 10mg/L after the feeding until no nutrient substance is added; controlling the concentration of dissolved oxygen in the aeration section to be 3-5 mg/L.

It will be appreciated by those skilled in the art that other steps or operations, such as further optimizing and/or improving the methods of the present invention, may be included before, after, or between any of the above steps S1-S2, (1) - (3) and a-d, so long as the objectives of the present invention are achieved.

Example 1

The embodiment is that the in-situ biological strengthening treatment technology of the polluted bottom mud in the anaerobic environment is as follows:

a test river A in a certain city in south China is in a black and odorous water body state for a long time, the depth of local sediment reaches 20cm, odor is obvious, aquatic fishes are rare, and the reaction of surrounding residents is strong. The SedCaN material is adopted for in-situ bottom mud treatment and water quality improvement, and the main implementation steps are as follows:

(1) and stabilizing the hydraulic condition. The requirements of the application of the SedCaN particles on river and lake hydraulic conditions comprise two requirements, namely, the river water flow condition is limited, the water flow is controlled to scour the bottom mud on the surface layer, conditions are provided for stable volatilization of decontamination efficiency of the SedCaN particles, and the treatment efficiency of bottom mud pollutants is guaranteed; secondly, under the condition of natural water flow, in order to avoid water flow disturbance of surface layer floating mud and even washing away SedCaN particles, the stability of the treatment efficiency is further influenced, and auxiliary measures are properly added.

In the embodiment, the test river A is in a natural flow condition, so that an in-situ covering method is adopted, and after SedCaN particles are thrown, river sand with the thickness of 5cm is paved to serve as a covering layer, so that on one hand, bottom mud pollution is prevented from being rapidly released, and on the other hand, the SedCaN particles are guaranteed to stably exert the purification capacity.

(2) The conditions and time of action are selected. The SedCaN particles are used by paying attention to seasonal temperature and action time, in order to ensure that the activation efficiency of the product on the microorganisms in the sediment is maximized, the SedCaN particles can be added at the temperature of 20-30 ℃, the optimal SedCaN particles are added in 5-10 months every year, and the temperature is basically maintained in the optimal microorganism growth range during the period, so that the growth of the microorganisms and the restoration of the sediment are facilitated.

(3) The bottom mud and water quality conditions are monitored regularly. In this embodiment, the fixed sampling points are used for monitoring the bottom mud and the water quality change and analyzing the treatment effect. In this example, the river a was monitored at 6 sampling points along the flow, and the results are shown in table 1, comparing the change of the main pollution index of the bottom mud at the 7-day treatment period. It can be seen that the reduction range of the organic matter content of the bottom sludge after 1 week of treatment is 38.4-46.2g/kg, and the reduction rate of the organic matter reaches 45.9-69.6%. The total nitrogen content is reduced to 1058mg/kg from 8200mg/kg on average, and the oxidation-reduction potential is increased by 81-157 mV.

By adopting the technology for synchronously removing carbon, nitrogen and sulfur pollutants from anaerobic bottom sludge, obvious effect is achieved on river A treatment, the appearances of the bottom sludge and the overlying water body before and after treatment are shown in figure 4, and the method not only improves the effect of treating bottom sludge pollution, but also improves the quality of the water in the in-situ river and lake.

TABLE 1-Experimental Change in the pollution indexes before and after treatment of river A sediment

Example 2

The embodiment is an in-situ polluted bottom mud remediation technology in a 'mud first and water second' mode, which is concretely as follows.

A test river B in a certain city in south China is 'broken-end gush' adjacent to an old city and a vegetable market, the length of the test river B is about 600m, the average gush width is about 6m, and the average water depth is 1.1 m. Since domestic sewage and a small amount of industrial wastewater are directly discharged into river, sediment is deposited thickly, and a water ecosystem is seriously damaged. In the embodiment, a water ecological restoration method in a 'mud-first-water' mode is adopted, firstly, oxygen-consuming substances at a river mud-water interface are quickly removed by utilizing a SedCaN material in an anaerobic environment; secondly, installing multi-gallery functional flora domestication and broadcasting equipment, directionally domesticating indigenous functional microbial flora by using bottom mud and water on the surface layer of the river B, continuously broadcasting aerobic microorganisms, and gradually constructing an aerobic microbial ecosystem of the water body, wherein the zoogloea diffuses to full gush along with water flow.

(1) And (4) performing in-situ SedCaN strengthening treatment on the bottom mud.

Concentration of volatile solids C in bottom mud of river B _VS 69g/kg, percentage of TOC content R _TOC 34% reduced sulfur content percentage R _S 15 percent, the designed oxidation depth of the bottom sediment is 20cm, the theoretical TOC/N for removing pollutants is 2.86, the S/N is 1.43, the density of the bottom sediment is 1.25kg/L, the safe input coefficient is 0.2, and the effective NO of SedCaN particles ₃ ^- If the proportion of-N content is 10%, the amount of SedCaN added is 4.56 kg/m ² 。

(2) A multi-gallery functional flora domestication and broadcasting device.

In the embodiment, the polluted bottom mud is repaired in situ by using the multi-gallery functional flora domestication and broadcasting equipment. Aiming at the problems that the growth rate of autotrophic nitrifying bacteria is low and the autotrophic nitrifying bacteria compete with heterotrophic bacteria in a poor state, the growth of the nitrifying bacteria with low growth rate is preferentially promoted by adding ammonia nitrogen to reduce the carbon-nitrogen ratio, so that the nitrifying bacteria can occupy the advantages in the total biomembrane bacteria; then carbon, nitrogen and phosphorus are supplemented, and the growth of autotrophic nitrifying bacteria and heterotrophic bacteria is promoted synchronously. The key process flow comprises the following steps:

1) fig. 3 schematically shows a multi-gallery functional microbial flora domestication and broadcasting device of the invention, which comprises a multi-gallery main body device 1, mainly comprising three core units, namely a mud-water separation unit 11, a directional domestication unit 12 and a strain broadcasting unit 13; a mud pump 2, a mud pump 3 and a guide wall 4; an aeration pump 5 and accessories thereof, wherein the accessories comprise an air flow meter 51 and an aeration disc 52; a nutrient solution dosing system 6 and a zoogloea broadcasting device 7.

2) Activation and enrichment of indigenous microorganisms. Adding bottom sludge 0-4cm in the surface layer of the water body to be treated and river surge water to be treated into a multi-gallery device to ensure that the volume ratio of the sludge to the water in the enrichment and domestication pool is 1:20-1:50, adding a nitrogen source to ensure that the concentration of ammonia nitrogen is 20-25mg/L, and adjusting the carbon nitrogen phosphorus ratio and the aeration intensity to ensure that the dissolved oxygen is 3-5 mg/L.

3) Microorganism domestication and broadcasting: setting a system to automatically feed in and out water, and adding a certain amount of carbon source and nitrogen source in the water flow direction to ensure that the carbon concentration is gradually reduced from 100mg/L and the ammonia nitrogen concentration is gradually reduced from 10mg/L after adding until no nutrient substance is added; controlling the concentration of dissolved oxygen in the aeration section to be 3-5 mg/L. After the second acclimation and adaptation, after the excess sludge of the equipment is increased, the acclimated microbial agent is put to the upstream end of the test river B, and functional zoogloea is continuously acclimated and thrown.

(3) The bottom mud and water quality are monitored regularly.

Column samples were taken at 20, 27 and 34 days of SedCaN pellet addition to observe the characteristics of the sediment, and as can be seen from fig. 5, the sediment was significantly improved from the black and odorous state before treatment. The feasibility and the effectiveness of the technology for anaerobically repairing the polluted bottom mud based on the SedCaN particles are proved.

After the multi-corridor domestication and broadcasting equipment normally operates, water quality sampling and analysis are respectively carried out on the downstream section of the microbial inoculum for broadcasting, and apparent characteristic changes of overlying water bodies before and after in-situ aerobic bacterial domestication and broadcasting in a' mud-first-water-after-treatment mode are shown in fig. 6, wherein A in fig. 6 is the effect before the technology is used, and B is the effect after the technology is used. In the first 12 days, the ammonia nitrogen in the test section is in a continuous descending trend from 17.5mg/L to 4.5mg/L, while the ammonia nitrogen in the control section is gradually reduced from 18.5mg/L to 14.3mg/L, as shown in FIG. 7A.

Long-term water quality monitoring is continuously carried out on the river channel for 9 months, wherein the ammonia nitrogen concentration changes as shown in figure 7B. The ammonia nitrogen concentration in the river water is 4mg/L after the anaerobic bottom mud is repaired, the ammonia nitrogen concentration in the river is gradually reduced to be lower than the V-type standard (2mg/L) of surface water after the aerobic microorganism ecological reconstruction, and the water quality is obviously improved.

While the invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Many modifications and variations may be made to the exemplary embodiments of the present description without departing from the scope or spirit of the present invention. The scope of the claims is to be accorded the broadest interpretation so as to encompass all modifications and equivalent structures and functions.

Claims (6)

1. A town river and lake water ecological restoration method based on a 'first mud and then water' new restoration mode is used for town river and lake bottom mud in-situ restoration and micro-ecological reconstruction, and is characterized by comprising the following steps:

s1, through in-situ denitrification biological enhancement of polluted bottom mud, oxygen-consuming substances on a mud-water interface are efficiently removed in an anaerobic environment, and black and odor of the bottom mud are rapidly eliminated, so that favorable conditions are created for restoring the aerobic environment of a water body, and the enhancement means that SedCaN particles are contacted with the polluted bottom mud, so that synchronous reduction of carbon, nitrogen and sulfur pollutants of the anaerobic bottom mud is realized; the SedCaN particles are prepared by the following method:

(1) directionally domesticating and enriching indigenous microorganism denitrifying functional flora by using a denitrifying liquid culture medium, and air-drying to obtain a microorganism dormancy body to prepare a microbial agent;

(2) mixing the microbial agent with nitrate to obtain a mixture;

(3) mixing the mixture with a binder and sodium alginate to prepare the SedCaN particles;

s2, activating aerobic active functional flora, recovering a pollution purification process comprising natural reoxygenation and aerobic reaction, further eliminating pollutants in all directions, and guiding a reconstructed mud-water aerobic microorganism health ecosystem, wherein a multi-gallery functional flora domestication and broadcasting device is installed, indigenous functional microorganism flora is domesticated directionally by using bottom mud on the surface layer of a river and a water body, aerobic microorganisms are continuously broadcast, and a zoogloea diffuses to a full surge along with water flow, so that an aerobic microorganism ecosystem of the water body is gradually constructed;

wherein, step S2 includes using the microorganism domestication scattering device to realize the construction of the aerobic microorganism ecosystem, wherein, the device includes a multi-corridor main body, a muddy water pump, a sludge pump, a guide wall and an aeration device, the multi-corridor main body includes a muddy water separation unit, a directional domestication unit for the activation and enrichment of indigenous microorganisms and a strain scattering unit for the domesticated microorganism agent scattering.

2. The ecological restoration method for urban river and lake water based on the 'first mud and then water' new restoration mode as claimed in claim 1, wherein the nitrate comprises calcium nitrate, sodium nitrate, potassium nitrate or a mixture thereof.

3. The urban river and lake water ecological restoration method based on the 'mud first and water second' new restoration mode as claimed in claim 2, wherein the mass ratio of the microbial agent to the nitrate is 1:5-1: 3.

4. The method for ecological restoration of water in rivers and lakes of towns based on the 'mud first then water' new restoration mode according to claim 1, wherein the binder is polyvinyl alcohol.

5. The ecological restoration method for the water of rivers and lakes in cities and towns based on the 'mud first then water' new restoration mode as claimed in claim 1, wherein the mass ratio of the mixture, the adhesive and the sodium alginate is 6-20:1: 1.

6. The method for ecological restoration of town river and lake water based on "mud first then water" new restoration mode as claimed in claim 1, wherein step S2 includes:

a. continuously collecting the floating mud on the surface layer of the polluted river or lake, primarily screening the floating mud, then entering a mud-water separation unit, arranging a baffle plate assembly by using a shallow layer precipitation principle, rapidly settling the floating mud under the action of centrifugal force and gravity, and collecting and obtaining high-concentration sludge;

b. adding high-concentration sludge and a microorganism enrichment culture solution into the directional domestication unit, regulating and controlling the directional domestication unit, and quickly enriching aerobic indigenous microorganisms to obtain a large amount of active functional zoogloea;

c. collecting the active functional zoogloea, and further culturing in the strain broadcasting unit to improve the environmental adaptability and stability of the functional bacteria;

d. according to the water body and the surface layer sediment pollutant concentration, the aerobic active zoogloea feeding amount is adjusted, the continuous broadcasting is carried out, and the microorganism condition for long-term water quality purification is provided.

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