River, lake and reservoir muddy water cross-medium pollution assessment and ecological management method

Abstract

The invention relates to a river, lake and reservoir muddy water cross-medium pollution assessment and ecological management method which comprises the following steps: establishing a reference system for river, lake and reservoir pollution multi-dimensional assessment, including a background value, a screening value, a control value and a set value; judging the current state of a target body according to the reference system, wherein the target body comprises an overlying water body, a mud-water interface and bottom mud; comprehensively evaluating the multi-dimensional cross-medium pollution of the target body, and judging the pollution type and pollution grade of the overlying water body, the pollution grade of nutritive salt and heavy metal in the bottom mud, and the cross-medium potential release risk and pollution contribution of the bottom mud to the overlying water body; based on multi-dimensional cross-medium pollution comprehensive evaluation, an ecological management measure system is formed, and a corresponding ecological management scheme is provided. The method effectively solves the problem that the engineering cost is high due to the fact that the sediment habitat structure is damaged or the desilting amount is large when lake and reservoir desilting treatment is carried out only from the single perspective of sediment pollution evaluation in the past, and has high application and popularization value.

Description

Technical Field

[0001] The present invention relates to the technical field of water ecological environment governance, and in particular to a method for cross-media pollution assessment and ecological governance of muddy water in rivers, lakes and reservoirs. Background Art

[0002] Currently, watershed water pollution assessments primarily focus on sediment pollution analysis in rivers, lakes, and reservoirs. Single assessment methods, such as visual stratification, background value, standard deviation multiples, Nemerow pollution index, ecological risk index, geological accumulation index, frequency control, or inflection point methods, are often used to assess soil (sediment) pollution risk type and pollution level. The type, level, and scope of sediment pollution guide whether to conduct remediation. The current technical assessment method, "sediment evaluation," has certain limitations for guiding environmental dredging projects. Using this assessment technique for lake and reservoir dredging can damage sediment habitat structure or lead to high project costs due to excessive dredging volumes.

[0003] In response to the above-mentioned existing technical problems, the present invention considers the spatial interaction of overlying water bodies, bottom mud bodies, and mud-water interfaces as a whole, establishes a reference system for pollution assessment (evaluation) of rivers, lakes and reservoirs, clarifies the assessment reference values ​​that are suitable for different scenarios, and analyzes the pollution situation and rating from the perspective of mud-water cross-media of overlying water bodies, bottom mud bodies and mud-water interfaces based on the multi-dimensional assessment method system of river and lake pollution in the invention patent (202410481821.5) disclosed by the applicant. The pollution situation and rating are analyzed, and the pollution situation of rivers, lakes and reservoirs is comprehensively assessed (evaluated), and effective treatment plans are proposed under different pollution scenarios of rivers, lakes and reservoirs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs includes the following steps:

[0007] S1. Establish a reference system for multidimensional assessment of river, lake and reservoir pollution, including background values, screening values, control values ​​and set values;

[0008] S2. Determine the current state of the target according to the reference system, wherein the target includes overlying water, mud-water interface, and bottom mud;

[0009] S3. Conduct a comprehensive multi-dimensional cross-media pollution assessment of the overlying water, mud-water interface, and bottom sediment to determine the pollution type and level of the overlying water, the nutrient and heavy metal pollution levels in the bottom sediment, and the potential cross-media release risk and pollution contribution of the bottom sediment to the overlying water.

[0010] S4. Based on a comprehensive multi-dimensional and cross-media pollution assessment, a system of ecological governance measures is formed and corresponding ecological governance plans are proposed.

[0011] According to the above technical solution, preferably, in step S1, the background value selected refers to the baseline content of chemical elements or chemical substances of various environmental factors when the natural environment is unpolluted; the screening value selected refers to the limit value of pollutant content in the soil when it has an adverse impact on the safety of edible agricultural products, crop growth or the ecological environment; the control value selected refers to the limit value of the content of major pollutants in the soil when there is a serious threat to the quality and safety of edible agricultural products; the set value selected refers to the reference value set as required by the owner.

[0012] According to the above technical solution, preferably, in step S2, the grades of the overlying water body include grade I, grade II, grade III, grade IV and grade V, the pollution levels of the bottom mud include unpolluted, polluted and heavily polluted, and the interaction conditions of the mud-water interface include the bottom mud contributing to the pollution of the overlying water body, the mud and water being in dynamic equilibrium, and the overlying water body contributing to the pollution of the bottom mud body.

[0013] According to the above technical solution, preferably, step S3 includes:

[0014] The water quality level is assessed by using the modified Nemerow pollution index and water quality index method to determine the pollution type and pollution level of the overlying water body;

[0015] The Nemerow pollution index and potential ecological risk index were used to assess the pollution levels of nutrients and heavy metals in dredged sediments.

[0016] According to the specific engineering conditions, the adsorption-desorption method, pore water diffusion model or laboratory simulation culture method are used to determine the pollutant concentration at the adsorption-desorption equilibrium, and the pollutant release rate N of the sediment is used to determine the pollutant concentration at the adsorption-desorption equilibrium. s To determine the potential cross-media release risk and pollution contribution of dredged sediment to the overlying water body.

[0017] According to the above technical solution, preferably, in step S4, the ecological governance solution includes:

[0018] When the level of the overlying water body is at level I or II, and the sediment pollutant release rate N s When <0, there is no need to treat water and sediment. If the sediment pollutant release rate N sWhen the value is ≥0, there is a risk of sediment release to the overlying water body, and sediment aquatic organism restoration and habitat maintenance plans should be implemented;

[0019] When the level of the overlying water body is at level III, and the sediment pollutant release rate N s When the release rate of sediment pollutants is less than 0, only water treatment is needed, water diversion is adopted to dilute the water pollution concentration, aquatic bioremediation is carried out, and external pollution control management is done well. s When the value is ≥0, there is a risk of release of sediment to overlying water. Ecological and environmental protection measures should be implemented for both water and sediment. Water should be diverted to overlying water bodies to dilute pollutant concentrations and aquatic bioremediation should be carried out. At the same time, sediment should be dredged and external pollution sources should be controlled.

[0020] When the overlying water body is at level IV and level V, ecological and environmental protection measures are implemented for both the water and the bottom sediment. The overlying water body is diverted to dilute the concentration of pollutants, and aquatic bioremediation, composite oxygen release agents or Fenton oxidation are used for treatment. At the same time, the bottom sediment is dredged and external pollution sources are controlled.

[0021] In the reference system, reference values ​​of background value, screening value, control value and set value are determined as the reference values ​​for judging whether the pollution of rivers and lakes exceeds the standard, including "the overlying water body exceeds the reference value, and the bottom sediment does not exceed the reference value", "the overlying water body does not exceed the reference value, and the bottom sediment exceeds the reference value", and "the overlying water body does not exceed the reference value, and the bottom sediment does not exceed the reference value", and corresponding ecological governance plans are proposed.

[0022] According to the above technical solution, preferably, when "the overlying water exceeds the reference value and the bottom sediment does not exceed the reference value", if the bottom sediment pollutant release rate N s >0, ecological and environmental protection measures are taken for both water and sediments, water is diverted to the overlying water body, the concentration of pollutants is diluted, and aquatic bioremediation is carried out, composite oxygen release agents or Fenton oxidation are used for treatment, combined with microbial remediation technology, dredging of the sediments, and control of external pollution sources. If the sediment pollutant release rate N s = 0, give priority to ecological and environmental protection measures for water treatment, take water diversion to dilute the water pollution concentration, carry out aquatic bioremediation, selectively dredge the bottom mud, and control the external pollution source. If the bottom mud pollutant release rate N s <0, only ecological and environmental protection measures are taken to treat the water, water diversion is adopted to dilute the concentration of water pollution, aquatic biological restoration is carried out at the same time, and external pollution control management is carried out.

[0023] When “the overlying water does not exceed the reference value, but the sediment exceeds the reference value”, if the sediment pollutant release rate N s> 0, only ecological and environmental protection measures are taken to treat the sediment, dredge the sediment, and control the external pollution sources. If the sediment pollutant release rate N s = 0, give priority to ecological and environmental protection measures for the sediment, dredge the sediment, control the external pollution source, selectively carry out aquatic bioremediation of the overlying water body, add composite oxygen release agents, and combine microbial remediation technology. If the sediment pollutant release rate N s <0, implement ecological and environmental protection measures for water and sediment, adjust the overlying water body, dilute the concentration of pollutants, carry out aquatic biological restoration, dredge the sediment, and control external pollution sources.

[0024] When “the overlying water body does not exceed the reference value and the bottom sediment does not exceed the reference value”, if the bottom sediment pollutant release rate N s >0, the sediment contributes to the pollution of the overlying water body. Ecological and environmental protection measures should be taken to treat the sediment to maintain a healthy ecological environment of the water body. At the same time, attention should be paid to aquatic biological restoration, adding composite oxygen release agents, combining microbial restoration technology, controlling exogenous pollution, and doing a good job in restoration project management. If the sediment pollutant release rate N s = 0, mud and water are in dynamic balance, and ecological and environmental protection measures are taken for both water and sediment, attention is paid to aquatic biological restoration, and external pollution is controlled, and restoration project management is done well. If the sediment pollutant release rate N s <0, the pollution of overlying water bodies contributes to the pollution of bottom sediments. Priority should be given to the implementation of ecological and environmental protection measures to manage water, maintain hydrodynamic conditions, maintain a good habitat, and control external pollution.

[0025] The beneficial effects of the present invention are:

[0026] 1. This invention conducts a comprehensive, cross-media assessment of rivers, lakes, and reservoirs from a multidimensional, cross-media perspective, encompassing the water, mud-water interface, and soil (sediment) as a whole, to assess the pollution status of these bodies. The proposed cross-media pollution assessment system and ecological management plan for rivers, lakes, and reservoirs breaks away from the existing approach of using a single method to assess sediment pollution to guide river and lake management. By conducting ecological dredging after multidimensional spatial assessment, the system can more effectively achieve ecological management of rivers, lakes, and reservoirs. This assessment system is suitable for assessing pollution in rivers, lakes, and reservoirs during ecological dredging. Compared with previous single-scale assessment methods, this system is more scientific and effective.

[0027] 2. The present invention establishes a reference system for the pollution assessment of water bodies in rivers, lakes and reservoirs, mud-water interface interaction space, and soil (bottom sediment), and proposes applicable engineering conditions for each reference system, making the assessment results more accurate and effective.

[0028] 3. The present invention comprehensively evaluates cross-media multi-dimensional targets, reference systems, multi-dimensional pollution evaluation method systems, cross-media states, etc., proposes evaluation results for various cross-media states, and stipulates a cross-media pollution evaluation system and ecological governance principles for rivers, lakes and reservoirs. It is suitable for ecological governance of various pollution situations in rivers, lakes and reservoirs. The invention has wide application and strong engineering applicability.

[0029] 4. This invention comprehensively assesses the impact of water, mud-water interface, and soil (bottom sediment) on river, lake, and reservoir pollution. It analyzes and derives ecological remediation solutions for varying pollution levels across multiple media, including water, soil, and the mud-water interface. It also provides a network of ecological remediation solutions tailored to client requirements or specific standards. This remediation solution provides more scientific guidance for ecological remediation of rivers, lakes, and reservoirs, addressing bottlenecks in previous ecological dredging projects, such as high project costs and limited ecological remediation effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the comprehensive pollution evaluation system for rivers, lakes and reservoirs and pollution control measures in the present invention.

[0031] Figure 2 It is a schematic diagram of the cross-media pollution assessment system for rivers, lakes and reservoirs and the ecological governance principles in the present invention.

[0032] Figure 3 It is an application example of the multi-dimensional assessment system and treatment plan for cross-media pollution of rivers, lakes and reservoirs in the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and the best embodiment. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without making any creative work shall fall within the scope of protection of the invention.

[0034] The overlying water body, the bottom mud body and the mud-water interface constitute a whole of the lake. The three parts are organically connected. It is impossible to solve the problem of river, lake and reservoir governance by governing or controlling any one part independently. In view of the limitations of the existing single evaluation method that only evaluates the bottom mud of rivers, lakes and reservoirs to judge the bottom mud pollution situation and serves as a reference for whether the ecological dredging of rivers, lakes and reservoirs should be carried out and the dredging depth, the task of the patent of this invention is to establish a mud-water cross-media evaluation system from the perspective of the organic whole composed of water body, mud-water interface and bottom mud body, comprehensively evaluate and analyze the pollution situation of rivers, lakes and reservoirs, propose governance plans under different pollution scenarios, scientifically guide endogenous governance projects, and effectively solve the loss of economic and environmental benefits.

[0035] The present invention provides a method for evaluating and ecologically managing cross-media pollution of muddy water in rivers, lakes and reservoirs, comprising the following steps:

[0036] S1. Establish a reference system for multidimensional assessment of river, lake and reservoir pollution, the reference system including background values, screening values, control values ​​and set values.

[0037] The selected background values ​​refer to the baseline concentrations of chemical elements or chemicals in various environmental factors in an unpolluted natural environment, reflecting the original state of environmental quality. Based on the actual requirements of the land surrounding the project, appropriate reference values ​​can be used to analyze pollution exceeding standards in rivers, lakes, and reservoirs. If local background values ​​exist, these reference values ​​should be used.

[0038] The selected screening value is the limit value of pollutant content in the soil when it has an adverse impact on the safety of edible agricultural products, crop growth or the ecological environment. If the pollutant content in the soil is lower than this value, the risk of agricultural products exceeding the standard can be ignored.

[0039] The control values ​​selected refer to the limits for major pollutant content in soil when the quality and safety of edible agricultural products are seriously compromised. The risk of agricultural products exceeding these limits is very high. If there is agricultural land near the project or if the owner specifies it, the reference values ​​will be the screening and control values ​​in the national standard "Soil Environmental Quality - Agricultural Land Soil Pollution Risk Control Standard" (GB 15618-2018) for the safety of the surrounding agricultural land. For safe use, the screening values ​​will be preferred.

[0040] The selected set value refers to the reference value set as required by the owner. If the owner specifies the surrounding utilization direction of the project or proposes a standard direction for the project requirements, the reference value shall be the set value. For example, if the lake and reservoir sediment is disposed of for surrounding construction land, the set value can be selected to meet the screening value of the national standard "Soil Environmental Quality - Construction Land Soil Pollution Risk Control Standard" (GB 36600-2018) as the reference value for river, lake and reservoir pollution assessment. If the water body is based on Class III water, the reference value for water pollution shall be the Class III water quality index value.

[0041] S2. Selecting an appropriate reference value according to the reference value selection rules in the reference system to judge the current state of the target body, wherein the target body includes the overlying water body, the mud-water interface, and the bottom mud.

[0042] The overlying water and sediment targets are selected as treatment standards based on a multidimensional assessment method for river and lake pollution based on ecological dredging disclosed in the applicant's prior application (202410481821.5). The overlying water levels include I, II, III, IV, and V, the sediment pollution levels include unpolluted, polluted, and heavily polluted, and the interaction between the mud and water interface includes the sediment's contribution to the overlying water, the mud and water being in dynamic equilibrium, and the overlying water's contribution to the sediment's pollution.

[0043] S3. Comprehensively evaluate the multi-dimensional cross-media pollution composed of the overlying water body, mud-water interface, and bottom sediment to determine the pollution type and pollution level of the overlying water body, the pollution level of nutrients and heavy metals in the bottom sediment, and the potential cross-media release risk and pollution contribution of the bottom sediment to the overlying water body.

[0044] Specifically, the water quality level is evaluated by modifying the Nemerow pollution index and the water quality index method to determine the pollution type and pollution level of the overlying water body; the Nemerow pollution index and the potential ecological risk index are used to evaluate the pollution level of nutrients and heavy metals in the dredged sediment; according to the specific engineering conditions, the adsorption-desorption method, the pore water diffusion model or the laboratory simulation culture method is used to determine the pollutant concentration at the adsorption-desorption equilibrium, and the sediment pollutant release rate N is used to determine the pollutant concentration at the adsorption-desorption equilibrium. s To determine the potential cross-media release risk and pollution contribution of dredged sediment to the overlying water body. s When N > 0, the sediment contributes to the pollution of the overlying water body, reflecting the release of pollutants in the sediment into the overlying water body. s = 0, the ion migration in the overlying water and bottom mud is in a dynamic equilibrium state. s When <0, the overlying water body contributes to the pollution of the bottom sediment, which mainly reflects the migration and adsorption of pollutants in the overlying water body into the bottom sediment.

[0045] S4. Based on a comprehensive multi-dimensional cross-media pollution assessment, a system of ecological governance measures is formed. Based on a comprehensive analysis of the assessment results of various parts of rivers, lakes and reservoirs, corresponding ecological governance plans are proposed.

[0046] The comprehensive assessment consists of selecting the reference value in step S1, the target body in step S2, and the evaluation of the pollution degree of mud and water in step S3, and the comprehensive analysis of the assessment results. Based on the specific conditions of rivers, lakes and reservoirs, the treatment plans adopted under different current conditions and assessment results are as follows:

[0047] (1) When the overlying water body is at level I or II, the water quality is relatively clean and does not require water treatment, that is, it is unpolluted. However, the medium- and long-term sediment pollutant storage capacity and potential release risk must also be considered. Therefore, at this water quality level, the degree of sediment pollution and whether the sediment poses a risk of pollutant release to the overlying water must be considered.

[0048] Specifically, if the level of the overlying water body is at level I or II, and the sediment pollutant release rate N s When <0, there is no need to treat water and sediment. If the sediment pollutant release rate N s When ≥0, there is a risk of sediment release to the overlying water body, and sediment aquatic biological restoration and habitat maintenance plans should be implemented.

[0049] (2) When the grade of the overlying water body is at level III, the water quality is at a lightly polluted level and water treatment is required. At the same time, it is necessary to understand the pollution of the bottom sediment and its ability to release pollution to the overlying water. It is necessary to consider the degree of bottom sediment pollution and whether the bottom sediment has the risk of releasing pollutants to the overlying water.

[0050] Specifically, if the level of the overlying water body is at level III and the sediment pollutant release rate N s When the release rate of sediment pollutants is less than 0, it is only necessary to treat the water, dilute the water pollution concentration, improve the hydrodynamic conditions, carry out aquatic bioremediation, and do a good job of external pollution control management. s When the value is ≥0, there is a risk of release of sediment to overlying water. Ecological and environmental protection measures should be taken to manage both water and sediment. Water of overlying water should be adjusted to dilute the concentration of pollutants, improve hydrodynamic conditions, and carry out aquatic biological restoration. At the same time, the sediment should be dredged, and external pollution sources should be controlled to ensure the operation and maintenance of the restoration project.

[0051] (3) When the overlying water body is at level IV or V, the water quality is at a moderate to severe pollution level and needs to be treated, while considering the degree of sediment pollution and whether the sediment poses a risk of pollutant release to the overlying water.

[0052] Specifically, if the grade of the overlying water body is at level IV and V, that is, at a heavy pollution level, ecological and environmental protection measures will be taken to treat both the water and the bottom sediment, the overlying water body will be adjusted to dilute the concentration of pollutants, improve the hydrodynamic conditions, and carry out aquatic biological restoration, composite oxygen release agents or Fenton oxidation for treatment, while the bottom sediment will be dredged, and external pollution sources will be controlled to ensure the operation and maintenance of the restoration project.

[0053] (4) If the treatment target is based on the owner's requirements or a certain standard, it is necessary to comprehensively evaluate the pollution of cross-media such as water bodies, bottom sediment bodies, and mud-water interfaces and take corresponding control measures. According to the needs or functional requirements to be achieved, the appropriate reference values ​​in the reference system (background value, screening value, control value, set value) established by the company through many years of engineering practice are selected as the judgment of whether the river and lake pollution exceeds the standard. There are three situations:

[0054] ① The overlying water exceeds the reference value, but the bottom sediment does not exceed the reference value

[0055] If the sediment pollutant release rate N sIf the water quality exceeds the standard, while the sediment does not, the sediment is contributing to the pollution of the overlying water. In this case, the remediation plan involves implementing ecological and environmental protection measures for both the water and the sediment. Overlying waters should be diverted to dilute pollutant concentrations and improve hydrodynamic conditions. At the same time, attention should be paid to aquatic bioremediation, including the addition of composite oxygen-releasing agents and the integration of microbial remediation techniques. Furthermore, ecological dredging of the sediment is required, and external pollution should be controlled, with effective management of the remediation project.

[0056] If the sediment pollutant release rate N s = 0. The assessment result indicates that the water body exceeds the standard, but the sediment does not, and the mud and water are in dynamic equilibrium. The treatment plan at this time is to prioritize ecological and environmental protection measures for the water. Water diversion is adopted to dilute the water pollution concentration and improve hydrodynamic conditions. Aquatic bioremediation is also carried out. Sediment is selectively dredged, and external pollution sources are controlled.

[0057] If the sediment pollutant release rate N s <0. The assessment indicates that the water body exceeds the standard, but the sediment does not. Pollution in the overlying water contributes to the sediment. In this case, the remediation plan is to implement ecological and environmental protection measures only for the water. Water diversion is used to dilute the water pollution concentration, improve hydrodynamic conditions, and carry out aquatic bioremediation. External pollution is controlled, and effective remediation project management is implemented.

[0058] ② The overlying water does not exceed the reference value, but the bottom sediment exceeds the reference value

[0059] If the sediment pollutant release rate N s >0, the evaluation result is that the water body does not exceed the standard, but the bottom sediment exceeds the standard, and the bottom sediment contributes to the pollution of the overlying water body. The treatment plan adopted at this time is to only implement ecological and environmental protection measures on the bottom sediment, dredge the bottom sediment, control external pollution sources, and do a good job in restoration project management.

[0060] If the sediment pollutant release rate N s =0, the evaluation result is that the water body does not exceed the standard, the bottom sediment exceeds the standard, and the mud and water are in dynamic balance. The treatment plan adopted at this time is to give priority to the ecological and environmental protection measures for the bottom sediment, dredge the bottom sediment, control the external pollution source, selectively carry out aquatic biological restoration of the overlying water body, add composite oxygen-releasing agents, and combine microbial restoration technology.

[0061] If the sediment pollutant release rate N s <0, the evaluation result is that the water body does not exceed the standard, the bottom sediment exceeds the standard, and the pollution of the overlying water body contributes to the pollution of the bottom sediment. The treatment plan adopted at this time is to take ecological and environmental protection measures to treat both the water and the bottom sediment, adjust the overlying water body, dilute the pollutant concentration, improve the hydrodynamic conditions, and carry out aquatic biological restoration, dredge the bottom sediment, control the external pollution source, and do a good job in the management of the restoration project.

[0062] ③ The overlying water body does not exceed the reference value, and the bottom sediment does not exceed the reference value

[0063] If the sediment pollutant release rate N s >0, the evaluation result is that the water body does not exceed the standard, the bottom sediment does not exceed the standard, and the bottom sediment contributes to the pollution of the overlying water body. The treatment plan adopted at this time is to take ecological and environmental protection measures to treat the bottom sediment, maintain a healthy ecological environment of the water body, and pay attention to aquatic biological restoration, add composite oxygen-releasing agents, combine microbial restoration technology, control exogenous pollution, and do a good job in restoration project management.

[0064] If the sediment pollutant release rate N s =0, the evaluation result is that the water body does not exceed the standard, the bottom sediment does not exceed the standard, and the mud and water are in dynamic balance. The treatment plan adopted at this time is to take ecological and environmental protection measures to treat both water and bottom sediment, pay attention to the restoration of aquatic organisms, control external pollution, and do a good job in the management of restoration projects.

[0065] If the sediment pollutant release rate N s <0, the evaluation result is that the water body does not exceed the standard, the bottom sediment does not exceed the standard, and the pollution of the overlying water body contributes to the pollution of the bottom sediment. The treatment plan adopted at this time is to give priority to the ecological and environmental protection measures for the water, maintain the hydrodynamic conditions, maintain a good habitat, and control exogenous pollution.

[0066] like Figure 3 As shown, if the water quality requirement reaches Level III (such as represented by the number 60) and the sediment quality reaches Level IV (such as represented by the number 80), according to the needs or functional requirements to be achieved, the appropriate reference values ​​in the reference system (background value, screening value, control value, set value) established by the company through many years of engineering practice are selected as the judgment of whether the river and lake pollution exceeds the standard. The water quality pollution rating evaluated by the multi-dimensional assessment method of river and lake sediments suitable for ecological dredging is Level V, and the sediment pollution level is Level IV. There are the following three situations:

[0067] ① When the release rate N at the mud-water interface s When it is >0, the evaluation result is that the water body exceeds the standard, the bottom sediment does not exceed the standard, but the bottom sediment contributes to the pollution of the overlying water body. At this time, the treatment plan adopted is to treat both water and soil. The corresponding treatment measures are to adjust the water to dilute the concentration of pollutants, improve the hydrodynamic conditions, pay attention to aquatic biological restoration, add composite oxygen-releasing agents, and combine microbial restoration technology. In addition, the bottom sediment must be ecologically dredged, and external pollution must be controlled, and the restoration project management must be done well.

[0068] ② When the release rate N at the mud-water interface s=0, the evaluation result is that the water body exceeds the standard, the bottom sediment does not exceed the standard, and the mud and water are in dynamic balance. At this time, the treatment plan adopted is to give priority to water treatment. The corresponding treatment measures are to adjust the water to dilute the concentration of pollutants, improve the hydrodynamic conditions, pay attention to the restoration of aquatic organisms, and optionally carry out ecological dredging of the bottom sediment, control external pollution, and do a good job in the management of the restoration project.

[0069] ③ When the release rate N at the mud-water interface s When it is less than 0, the evaluation result is that the water body exceeds the standard, the bottom sediment does not exceed the standard, and the pollution of the overlying water body contributes to the pollution of the bottom sediment. At this time, the treatment plan adopted is to treat the water specifically. The corresponding treatment measures are to adjust the water to dilute the concentration of pollutants, improve the hydrodynamic conditions, carry out aquatic biological restoration, control exogenous pollution, and do a good job in restoration project management.

[0070] In summary, this application provides a method for cross-media pollution assessment and ecological management of mud and water in rivers, lakes and reservoirs, proposes a reference system for pollution assessment of rivers, lakes and reservoirs, and explains the applicable scope of reference values ​​such as suitable engineering conditions and engineering scenarios. It conducts a comprehensive assessment of pollution in rivers, lakes and reservoirs from the spatial scales of water bodies, mud-water interface interaction space, and soil bodies (bottom mud bodies), establishes a network of ecological management solutions for rivers, lakes and reservoirs, and takes corresponding management measures according to different pollution situations. This application solves the problems of the destruction of the bottom mud habitat structure or the high engineering costs caused by excessive dredging volume caused by the previous consideration of lake and reservoir dredging management from the single perspective of bottom mud pollution assessment. It scientifically guides endogenous management projects, breaks through the bottleneck of existing technologies in water ecological management of environmental dredging projects for rivers, lakes and reservoirs, and has high application and promotion value.

[0071] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs, characterized by: The steps include: S1. Establish a reference system for multidimensional assessment of river, lake and reservoir pollution, including background values, screening values, control values ​​and set values; S2. Determine the current state of the target according to the reference system, wherein the target includes overlying water, mud-water interface, and bottom mud; S3. Conduct a comprehensive multi-dimensional cross-media pollution assessment of the overlying water, mud-water interface, and bottom sediment to determine the pollution type and level of the overlying water, the nutrient and heavy metal pollution levels in the bottom sediment, and the potential cross-media release risk and pollution contribution of the bottom sediment to the overlying water. S4. Based on a comprehensive multi-dimensional and cross-media pollution assessment, a system of ecological governance measures is formed and corresponding ecological governance plans are proposed.

2. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 1, characterized in that: In step S1, the background value selected refers to the baseline content of chemical elements or chemical substances of various environmental factors when the natural environment is not polluted; The limit of pollutant content in soil when the selected screening value has an adverse impact on the safety of edible agricultural products, crop growth or ecological environment; The selected control values ​​refer to the limits of the main pollutant content in the soil when there is a serious threat to the quality and safety of edible agricultural products; The selected set value refers to the reference value set by the owner.

3. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 2, characterized in that: In step S2, the levels of the overlying water body include level I, level II, level III, level IV and level V. The pollution levels of the sediment include unpolluted, polluted and heavily polluted. The interaction conditions of the mud-water interface include that the bottom mud contributes to the pollution of the overlying water body, the mud and water are in dynamic equilibrium, and the overlying water body contributes to the pollution of the bottom mud body.

4. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 3, characterized in that: Step S3 includes: The water quality level is assessed by using the modified Nemerow pollution index and water quality index method to determine the pollution type and pollution level of the overlying water body; The Nemerow pollution index and potential ecological risk index were used to assess the pollution levels of nutrients and heavy metals in dredged sediments. According to the specific engineering conditions, the adsorption-desorption method, pore water diffusion model or laboratory simulation culture method are used to determine the pollutant concentration at the adsorption-desorption equilibrium, and the pollutant release rate N of the sediment is used to determine the pollutant concentration at the adsorption-desorption equilibrium. s To determine the potential cross-media release risk and pollution contribution of dredged sediment to the overlying water body.

5. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 4, characterized in that: In step S4, the ecological governance plan includes: When the level of the overlying water body is at level I or II, and the sediment pollutant release rate N s When <0, there is no need to treat water and sediment. If the sediment pollutant release rate N s When the value is ≥0, there is a risk of sediment release to the overlying water body, and sediment aquatic organism restoration and habitat maintenance plans should be implemented; When the level of the overlying water body is at level III, and the sediment pollutant release rate N s When the release rate of sediment pollutants is less than 0, only water treatment is needed, water diversion is adopted to dilute the water pollution concentration, aquatic bioremediation is carried out, and external pollution control management is done well. s When the value is ≥0, there is a risk of release of sediment to overlying water. Ecological and environmental protection measures should be implemented for both water and sediment. Water should be diverted to overlying water bodies to dilute pollutant concentrations and aquatic bioremediation should be carried out. At the same time, sediment should be dredged and external pollution sources should be controlled. When the grade of the overlying water body is at level IV and level V, ecological and environmental protection measures are implemented for both the water and the bottom sediment. The overlying water body is adjusted to dilute the concentration of pollutants, and aquatic biological restoration is carried out. Composite oxygen release agents or Fenton oxidation are used for treatment. At the same time, the bottom sediment is dredged and external pollution sources are controlled.

6. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 5, characterized in that: In step S4, the ecological governance plan further includes: In the reference system, reference values ​​of background value, screening value, control value and set value are determined as the reference values ​​for judging whether the pollution of rivers and lakes exceeds the standard, including "the overlying water body exceeds the reference value, and the bottom sediment does not exceed the reference value", "the overlying water body does not exceed the reference value, and the bottom sediment exceeds the reference value", and "the overlying water body does not exceed the reference value, and the bottom sediment does not exceed the reference value", and corresponding ecological governance plans are proposed.

7. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 6, characterized in that: In step S4, when "the overlying water exceeds the reference value, and the bottom mud does not exceed the reference value", If the sediment pollutant release rate N s >0, implement ecological and environmental protection measures for both water and sediment, adjust the overlying water body, dilute the concentration of pollutants, and carry out aquatic bioremediation, composite oxygen release agents or Fenton oxidation for treatment, combine microbial remediation technology, dredge the sediment at the same time, and control external pollution sources. If the sediment pollutant release rate N s =0, prioritize ecological and environmental protection measures for water management, adopt water diversion to dilute water pollution concentrations, carry out aquatic bioremediation, selectively dredge bottom sediments, and control external pollution sources. If the sediment pollutant release rate N s <0, only ecological and environmental protection measures are taken to treat the water, water diversion is adopted to dilute the concentration of water pollution, aquatic biological restoration is carried out at the same time, and external pollution control management is carried out.

8. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 7, characterized in that: In step S4, when "the overlying water does not exceed the reference value, and the bottom sediment exceeds the reference value", If the sediment pollutant release rate N s >0, only ecological and environmental protection measures are taken to treat the bottom sediment, dredge the bottom sediment, and control external pollution sources. If the sediment pollutant release rate N s =0, give priority to ecological and environmental protection measures for sediment management, dredge the sediment, control external pollution sources, selectively carry out aquatic bioremediation of overlying water bodies, add composite oxygen release agents, and combine microbial remediation technology. If the sediment pollutant release rate N s <0, implement ecological and environmental protection measures for water and sediment, adjust the overlying water body, dilute the concentration of pollutants, carry out aquatic biological restoration, dredge the sediment, and control external pollution sources.

9. A method for cross-media pollution assessment and ecological management of muddy water in rivers, lakes and reservoirs according to claim 8, characterized in that: In step S4, when "the overlying water does not exceed the reference value and the bottom sediment does not exceed the reference value", If the sediment pollutant release rate N s >0, the bottom sediment contributes to the pollution of the overlying water body. Ecological and environmental protection measures should be taken to treat the bottom sediment to maintain a healthy ecological environment of the water body. At the same time, attention should be paid to the restoration of aquatic organisms, adding composite oxygen-releasing agents, combining microbial restoration technology, controlling exogenous pollution, and doing a good job in the management of restoration projects. If the sediment pollutant release rate N s = 0, mud and water are in dynamic balance, and ecological and environmental protection measures are taken for both water and bottom mud, attention is paid to the restoration of aquatic organisms, and external pollution is controlled, and restoration project management is done well. If the sediment pollutant release rate N s <0, the pollution of overlying water bodies contributes to the pollution of bottom sediments. Priority should be given to the implementation of ecological and environmental protection measures to manage water, maintain hydrodynamic conditions, maintain a good habitat, and control external pollution.

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