A method for treating in-situ sediment using hydrogel slow-release oxygen material

Abstract

The present invention belongs to the technical field of water environment restoration and treatment, and relates to a method for treating in-situ sediment using a hydrogel slow-release oxygen material. The method comprises: detecting the redox potential of sediment in a target area to obtain an oxygen demand evaluation value, and determining a delivery method of the hydrogel slow-release oxygen material according to the oxygen demand evaluation value, wherein the delivery method includes covering delivery and turning delivery; periodically collecting the brightness of the sediment in the target area to obtain a sediment remediation evaluation value; when it is determined according to the sediment remediation evaluation value that the sediment purification does not meet a preset standard, a secondary determination is made as to whether the sediment purification meets the preset standard according to a rate of change of the number of pores on the sediment surface, or the reason for the non-compliance is determined according to a distribution characterization value; when it is determined that the sediment purification meets the preset standard, the dissolved oxygen concentration of the overlying water is collected and the delivery frequency of the hydrogel slow-release oxygen material is corrected according to the rate of change of the dissolved oxygen concentration, thereby improving the sediment purification efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of water environment purification and treatment, and relates to a method for treating in-situ sediment by utilizing a hydrogel slow-release oxygen material. Background Art

[0002] In water environmental management, sediment, as a crucial component of aquatic ecosystems, has a direct impact on its overall health. While sediments are rich in organic matter, microorganisms, and various nutrients, they can also accumulate significant amounts of pollutants, such as heavy metals and organic pollutants. The long-term retention of these pollutants in sediments not only harms benthic organisms but can also affect the quality of overlying water bodies through exchange reactions at the sediment-water interface.

[0003] Hydrogel slow-release oxygen material is a hydrogel material that combines the water absorption and water retention properties of hydrogel with the function of slow-release oxygen. It can continuously provide dissolved oxygen to water bodies or sediments for a certain period of time, thereby improving water quality and sediment environment. Hydrogel slow-release oxygen material can slowly release oxygen, increase the redox potential of sediments, and promote the biodegradation of pollutants in sediments. Among them, how to efficiently and accurately use hydrogel slow-release oxygen material for sediment purification is crucial.

[0004] Chinese patent publication number: CN111847813A, discloses a method for in-situ remediation of bottom sediment, comprising: S1, dividing the water area to be remediated into a plurality of cells; S2, fixing the remediation system on the bottom sediment of the water area to be remediated by fixing parts; S3, filling the grooves with growth media, and planting aquatic plants in the grooves corresponding to the remediation system according to the level of the cells; S4, controlling the opening time of the control valve according to different remediation time periods, and adjusting the amount of remediation agent injected into the slow-release pipeline network.

[0005] It can be seen that the above technical solution relies on the plant growth cycle to limit the repair speed and only adjusts the amount of agent added according to the preset time period. It does not take into account the impact of changes in the brightness of the sediment, the number of pores on the sediment surface, and the dissolved oxygen concentration of the overlying water on the addition of the repair agent, resulting in low sediment purification efficiency. Summary of the Invention

[0006] To this end, the present invention provides a method for treating in-situ sediment using a hydrogel slow-release oxygen material, so as to overcome the problem in the prior art of relying on the plant growth cycle to limit the repair speed and only adjusting the amount of the agent according to a preset time period, without considering the impact of the brightness of the sediment, the number of pores on the surface of the sediment, and the dissolved oxygen concentration of the overlying water on the release of the repair agent, thereby resulting in low sediment purification efficiency.

[0007] To achieve the above object, the present invention provides a method for treating in-situ sediment using a hydrogel slow-release oxygen material, comprising:

[0008] Detecting the redox potential of the sediment in the target area to obtain an oxygen demand evaluation value, and determining a method for placing the hydrogel slow-release oxygen material based on the oxygen demand evaluation value, wherein the method includes covering placement and flipping placement;

[0009] Periodically collect the brightness of the bottom sediment in the target area to obtain the bottom sediment purification evaluation value;

[0010] When it is determined that the sediment purification does not meet the preset standard according to the sediment purification evaluation value, a distribution characterization value is obtained based on the placement depth of the hydrogel slow-release oxygen material, and the reason why the sediment purification does not meet the preset standard is determined according to the distribution characterization value, or a secondary determination is made as to whether the sediment purification meets the preset standard based on the rate of change of the number of pores on the sediment surface;

[0011] When it is determined that the purification of the bottom mud meets the preset standards, the dissolved oxygen concentration of the overlying water is collected and the frequency of the hydrogel slow-release oxygen material is corrected according to the rate of change of the dissolved oxygen concentration;

[0012] Among them, the brightness of the bottom mud is measured using a colorimeter. The brightness of the bottom mud refers to the brightness of the color on the surface of the bottom mud.

[0013] The sediment purification evaluation value is calculated using the following formula: Where E represents the sediment purification evaluation value; L1 represents the brightness of the sediment before purification; L0 represents the brightness of the target yellow-brown sediment, and L0 is set to 45; L2 represents the brightness of the sediment measured during the purification process.

[0014] Furthermore, the method of placing the hydrogel slow-release oxygen material is determined according to the oxygen demand evaluation value of the sediment, wherein:

[0015] If the oxygen demand evaluation value is less than the preset oxygen demand evaluation value, the coverage delivery method is selected;

[0016] If the oxygen demand evaluation value is greater than or equal to the preset oxygen demand evaluation value, the flipping delivery method is selected;

[0017] Furthermore, the covering delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate, and a preset delivery frequency;

[0018] The stirring delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate and a preset delivery frequency, while stirring the bottom mud in the target area.

[0019] Furthermore, the process of obtaining the oxygen demand evaluation value of the sediment includes:

[0020] Multiple sampling points are evenly selected within the target area, and sediment of a preset thickness is collected;

[0021] Insert the probe of the redox potential meter into the bottom mud and record the redox potential value;

[0022] The arithmetic mean of the redox potential values ​​of all sampling points is recorded as the oxygen demand evaluation value of the sediment.

[0023] Furthermore, the process of determining whether the sediment purification does not meet the preset standard according to the sediment purification evaluation value includes:

[0024] Obtaining a sediment purification evaluation value based on the brightness of the sediment;

[0025] Comparing the sediment purification evaluation value with the first preset sediment purification threshold and the second preset sediment purification threshold respectively;

[0026] If the sediment purification evaluation value is less than the first preset sediment purification threshold, it is determined that the sediment purification does not meet the preset standard, and the reason why the sediment purification does not meet the preset standard is determined based on the distribution characterization value of the gel slow-release oxygen material;

[0027] If the sediment purification evaluation value is greater than or equal to the first preset sediment purification threshold and less than the second preset sediment purification threshold, it is determined that the sediment purification does not meet the preset standard, and a second determination is made based on the rate of change of the number of pores on the sediment surface whether the sediment purification meets the preset standard;

[0028] Among them, the first preset sediment purification threshold is less than the second preset sediment purification threshold.

[0029] Furthermore, the rate of change of the number of pores on the surface is used to determine whether the sediment purification meets the preset standards.

[0030] If the pore number change rate is less than the preset pore number change rate, it is determined that the sediment purification does not meet the preset standard, and the amount of hydrogel slow-release oxygen material added is increased according to the difference between the preset pore number change rate and the pore number change rate;

[0031] If the pore number change rate is greater than or equal to the preset pore number change rate, it is determined that the sediment purification meets the preset standard;

[0032] The pore number change rate is the ratio between the pore number after the sediment surface is purified and the pore number before the sediment surface is purified.

[0033] Furthermore, there are several increasing methods for increasing the dosage of the hydrogel slow-releasing oxygen material, and each increasing method increases the dosage of the hydrogel slow-releasing oxygen material by a different amount.

[0034] Furthermore, the reason why the sediment purification does not meet the preset standards is determined based on the distribution characterization value of the hydrogel slow-release oxygen material, wherein:

[0035] If the distribution characterization value is less than the preset distribution characterization value, it is determined that the reason why the sediment purification does not meet the preset standard is that the hydrogel slow-release oxygen material is suspended and retained in the overlying water, and an early warning is issued;

[0036] If the distribution characterization value is greater than or equal to the preset distribution characterization value, it is determined that the reason why the sediment purification does not meet the preset standard is that the hydrogel slow-release oxygen material is unevenly distributed, and the distribution rate of the hydrogel slow-release oxygen material is increased according to the difference between the preset distribution characterization value and the distribution characterization value;

[0037] The distribution characterization value is the ratio of the placement depth of the hydrogel slow-release oxygen material to the preset depth.

[0038] Furthermore, the increase in the delivery rate of the hydrogel slow-release oxygen material is positively correlated with the distribution difference, wherein the distribution difference is the difference between the preset distribution characterization value and the distribution characterization value.

[0039] Furthermore, the frequency of delivery of the hydrogel slow-release oxygen material is modified according to the rate of change of the dissolved oxygen concentration of the overlying water, wherein:

[0040] If the dissolved oxygen concentration change rate is less than the preset dissolved oxygen concentration change rate, the injection frequency of the hydrogel slow-release oxygen material will not change;

[0041] If the dissolved oxygen concentration change rate is greater than or equal to the preset dissolved oxygen concentration change rate, the frequency of adding the hydrogel slow-release oxygen material is reduced according to the difference between the preset dissolved oxygen concentration change rate and the dissolved oxygen concentration change rate.

[0042] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention calculates the oxygen demand evaluation value in real time based on redox potential detection and dynamically switches the covering or flipping delivery mode, thereby improving the remediation efficiency, using the sediment purification evaluation value for judgment and the pore number change rate for secondary judgment, reducing the misjudgment rate, and ensuring the reliability of the multi-dimensional judgment mechanism; combining the distribution characterization value to accurately locate the cause of non-compliance, and at the same time dynamically adjusting the delivery frequency through the dissolved oxygen concentration change rate, realizing dynamic matching of the dosage of the agent and the degree of pollution, reducing agent waste, and thus improving the purification and remediation efficiency of the sediment.

[0043] Furthermore, when the sediment purification evaluation value does not meet the standard, the present invention performs a secondary judgment through the pore quantity change rate, or determines the reason for not meeting the standard in combination with the distribution characterization value, thereby reducing the misjudgment rate and improving the reliability of the evaluation.

[0044] Furthermore, the present invention determines the reason why the purification does not meet the standards based on the distribution characterization value of the hydrogel slow-release oxygen material, and adjusts the delivery rate accordingly or prevents the problem of suspension and retention of the hydrogel slow-release oxygen material, making the delivery strategy more scientific and reasonable, thereby optimizing the dynamic adjustment strategy.

[0045] Furthermore, the present invention realizes precise control of the increase amplitude of the delivery rate of the hydrogel slow-release oxygen material by arranging that the increase amplitude of the delivery rate of the hydrogel slow-release oxygen material is positively correlated with the distribution difference.

[0046] Furthermore, the present invention dynamically adjusts the dosage frequency based on the dissolved oxygen concentration change rate to avoid excessive hydrogel slow-release oxygen material, thereby improving the utilization rate of the hydrogel slow-release oxygen material. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 The figure is a flow chart of a method for treating in-situ sediment using a hydrogel slow-release oxygen material according to an embodiment of the present invention.

[0048] Figure 2 This is a flow chart of an embodiment of the present invention for determining the method for delivering hydrogel slow-release oxygen material according to the oxygen demand evaluation value of the sediment.

[0049] Figure 3 This is a flow chart of an embodiment of the present invention for determining whether the purification of sediment meets the preset standard based on the sediment purification evaluation value.

[0050] Figure 4 This is a flow chart of determining the reason why the purification of sediment does not meet the preset standard based on the distribution characterization value of the hydrogel slow-release oxygen material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0052] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0053] It should be pointed out that the data in this embodiment are all obtained by comprehensive analysis and evaluation of the historical test data of the present invention in the three months before this test and the corresponding historical test results. Those skilled in the art can understand that the method of determining the above-mentioned single parameter of the method of the present invention can be to select the value with the highest proportion as the preset standard parameter according to the data distribution, use weighted summation to use the obtained value as the preset standard parameter, substitute each historical data into a specific formula and use the value obtained by the formula as the preset standard parameter or other selection methods, as long as the method of the present invention can clearly define the different specific situations in the single determination process through the obtained value.

[0054] See also Figure 1 、 Figure 2 、 Figure 3 as well as Figure 4 As shown, they are respectively a flow chart of a method for treating in-situ sediment using a hydrogel slow-release oxygen material according to an embodiment of the present invention; a flow chart of determining a method for delivering the hydrogel slow-release oxygen material according to an oxygen demand evaluation value of the sediment according to an embodiment of the present invention; a flow chart of determining whether the sediment purification meets the preset standard according to the sediment purification evaluation value according to an embodiment of the present invention; and a flow chart of determining the reason why the sediment purification does not meet the preset standard according to the distribution characterization value of the hydrogel slow-release oxygen material according to an embodiment of the present invention.

[0055] An embodiment of the present invention provides a method for treating in-situ sediment using a hydrogel slow-release oxygen material, comprising:

[0056] Step S1, detecting the redox potential of the sediment in the target area to obtain an oxygen demand evaluation value, and determining a delivery method of the hydrogel slow-release oxygen material according to the oxygen demand evaluation value, wherein the delivery method includes covering delivery and flipping delivery;

[0057] Step S2: Periodically collect the brightness of the bottom sediment in the target area every three days to obtain a bottom sediment purification evaluation value;

[0058] Step S3: when it is determined that the sediment purification does not meet the preset standard according to the sediment purification evaluation value, a distribution characterization value is obtained based on the placement depth of the hydrogel slow-release oxygen material, and the reason why the sediment purification does not meet the preset standard is determined according to the distribution characterization value, or a secondary determination is made as to whether the sediment purification meets the preset standard based on the rate of change of the number of pores on the sediment surface;

[0059] Step S4: When it is determined that the purification of the bottom mud meets the preset standard, the dissolved oxygen concentration of the overlying water is collected and the injection frequency of the hydrogel slow-release oxygen material is corrected according to the change rate of the dissolved oxygen concentration.

[0060] In this embodiment, the hydrogel slow-release oxygen material is prepared from polyvinyl alcohol, calcium peroxide and activated carbon by a freeze-thaw-crosslinking method.

[0061] In this embodiment, the brightness of the bottom mud is measured every three days using a colorimeter. The brightness of the bottom mud refers to the brightness of the color on the surface of the bottom mud.

[0062] Specifically, the method of placing the hydrogel slow-release oxygen material is determined according to the oxygen demand evaluation value of the sediment, wherein:

[0063] If the oxygen demand evaluation value is less than the preset oxygen demand evaluation value -80mV, the coverage delivery method is selected;

[0064] If the oxygen demand evaluation value is greater than or equal to the preset oxygen demand evaluation value, the flipping delivery method is selected.

[0065] In this embodiment, the preset oxygen demand evaluation value has a value range of (-100 mV, -60 mV). Preferably, the preset oxygen demand evaluation value is selected as -80 mV.

[0066] Specifically, the covering delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate, and a preset delivery frequency;

[0067] The stirring delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate and a preset delivery frequency, while stirring the bottom mud in the target area.

[0068] In this embodiment, the hydrogel slow-release oxygen material is added according to a preset amount of 250 g / m², a preset addition rate, and a preset frequency of 4 times / day. The stirring method adopts spiral stirring, the stirring depth is 60% to 80% of the thickness of the bottom mud, and the rotation speed is controlled at 20 to 40 rpm.

[0069] Specifically, the process of obtaining the oxygen demand evaluation value of sediment includes:

[0070] Multiple sampling points were evenly selected within the target area, and a preset thickness of 5 cm of bottom mud was collected;

[0071] Insert the probe of the redox potential meter into the bottom mud and record the redox potential value;

[0072] The redox potential values ​​of all sampling points were added together and then divided by the total number of sampling points to obtain the arithmetic mean of the redox potential of the sediment in the target area, which was recorded as the oxygen demand evaluation value of the sediment.

[0073] Specifically, the process of determining whether the sediment purification meets the preset standards based on the sediment purification evaluation value includes:

[0074] Obtaining a sediment purification evaluation value based on the brightness of the sediment;

[0075] The sediment purification evaluation value is compared with the first preset sediment purification threshold value of 0.43 and the second preset sediment purification threshold value of 0.85 respectively;

[0076] If the sediment purification evaluation value is less than the first preset sediment purification threshold value of 0.43, it is determined that the sediment purification does not meet the preset standard, and the reason why the sediment purification does not meet the preset standard is determined based on the distribution characterization value of the gel slow-release oxygen material;

[0077] If the sediment purification evaluation value is greater than or equal to the first preset sediment purification threshold and less than the second preset sediment purification threshold of 0.85, it is determined that the sediment purification does not meet the preset standard, and a second determination is made based on the change rate of the number of pores on the sediment surface to determine whether the sediment purification meets the preset standard;

[0078] If the sediment purification evaluation value is greater than or equal to the second preset sediment purification threshold, it is determined that the sediment purification meets the preset standard;

[0079] Among them, the first preset sediment purification threshold is less than the second preset sediment purification threshold.

[0080] In this embodiment, the first preset sediment purification threshold is generally selected from the range of [0.30, 0.60], and the second preset sediment purification threshold is generally selected from the range of [0.70, 0.98]. Preferably, the first preset sediment purification threshold is selected as 0.43, and the second preset sediment purification threshold is selected as 0.85.

[0081] The sediment purification evaluation value is calculated using the following formula:

[0082] Where E represents the sediment purification evaluation value; L1 represents the brightness of the sediment before purification; L0 represents the brightness of the target yellow-brown sediment, and L0 is set to 45; L2 represents the brightness of the sediment measured during the purification process.

[0083] Specifically, the rate of change of the number of pores on the surface is used to determine whether the sediment purification meets the preset standards.

[0084] If the pore number change rate is less than the preset pore number change rate of 1.6, it is determined that the sediment purification does not meet the preset standard, and the amount of hydrogel slow-release oxygen material added is increased according to the difference between the preset pore number change rate and the pore number change rate;

[0085] If the pore number change rate is greater than or equal to the preset pore number change rate, it is determined that the sediment purification meets the preset standard;

[0086] The pore number change rate is the ratio between the pore number after the sediment surface is purified and the pore number before the sediment surface is purified.

[0087] Collect sediment samples before and after purification, align the target area using image registration technology, perform 3D imaging of the sediment surface using CT scanning, and use image processing software such as ImageJ or Avizo to identify the pore boundaries on the sediment surface and count the number. The process of aligning the target area using the above image registration technology is a routine process and will not be repeated here.

[0088] Specifically, there are several ways to increase the amount of hydrogel slow-release oxygen material, among which:

[0089] If the pore change difference is less than the first preset pore change difference of 0.3, the first adjustment coefficient of 1.02 is used to increase the dosage of the hydrogel slow-release oxygen material to the corresponding value;

[0090] If the pore change difference is greater than or equal to the first preset pore change difference and less than the second preset pore change difference of 0.5, the second adjustment coefficient of 1.04 is used to increase the dosage of the hydrogel slow-release oxygen material to the corresponding value;

[0091] If the pore change difference is greater than or equal to the second preset pore change difference, the dosage of the hydrogel slow-release oxygen material is increased to the corresponding value using a third adjustment coefficient of 1.06;

[0092] The pore change difference is the difference between the preset pore number change rate and the pore number change rate.

[0093] Specifically, the reasons why the sediment purification does not meet the preset standards are determined based on the distribution characterization values ​​of the hydrogel slow-release oxygen material, among which,

[0094] If the distribution characterization value is less than the preset distribution characterization value of 0.85, it is determined that the reason why the sediment purification does not meet the preset standard is that the hydrogel slow-release oxygen material is suspended and retained in the overlying water, and an early warning is issued;

[0095] If the distribution characterization value is greater than or equal to the preset distribution characterization value, it is determined that the reason why the sediment purification does not meet the preset standard is that the hydrogel slow-release oxygen material is unevenly distributed, and the distribution rate of the hydrogel slow-release oxygen material is increased according to the difference between the preset distribution characterization value and the distribution characterization value;

[0096] The distribution characterization value is the ratio of the placement depth of the hydrogel slow-release oxygen material to the preset depth of 0.4 m.

[0097] The placement depth of the hydrogel slow-release oxygen material is obtained by a columnar sampler.

[0098] Specifically, the preset depth can be adjusted by technical personnel in this field according to the different depths of the pollutant-enriched layers of the riverbed mud to be purified, wherein the pollutant-enriched layer can be an organic matter-enriched layer or a heavy metal-enriched layer, and there is no specific limitation, as long as the mud purification requirements are met.

[0099] Specifically, the increase in the delivery rate of the hydrogel sustained-release oxygen material is positively correlated with the distribution difference, wherein the positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation, and the linear slope of the linear positive correlation is not specifically limited. It can be understood that the greater the distribution difference, the greater the increase in the delivery rate of the hydrogel sustained-release oxygen material, and the distribution difference is the difference between the preset distribution characterization value and the distribution characterization value.

[0100] Specifically, the frequency of delivery of the hydrogel slow-release oxygen material is modified according to the rate of change of the dissolved oxygen concentration of the overlying water, wherein:

[0101] If the dissolved oxygen concentration change rate is less than the preset dissolved oxygen concentration change rate ‌0.9 mg / (L·h)‌, the injection frequency of the hydrogel sustained-release oxygen material will not be changed;

[0102] If the dissolved oxygen concentration change rate is greater than or equal to the preset dissolved oxygen concentration change rate, the frequency of adding the hydrogel slow-release oxygen material is reduced according to the difference between the preset dissolved oxygen concentration change rate and the dissolved oxygen concentration change rate.

[0103] In this embodiment, by setting a threshold of 0.9 mg / (L·h) and a differential feedback mechanism, the oxygen supply demand for sediment purification is guaranteed while the waste of hydrogel slow-release oxygen material is avoided.

[0104] The dissolved oxygen concentration change rate is calculated by the following formula:

[0105] Where Q represents the rate of change of dissolved oxygen concentration; C1 represents the initial dissolved oxygen concentration of the overlying water; C2 represents the dissolved oxygen concentration of the overlying water after sediment purification; and t represents the treatment time required for the sediment purification to meet the preset standards.

[0106] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0107] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for treating in-situ sediment using a hydrogel slow-release oxygen material, characterized in that: include: Detecting the redox potential of the sediment in the target area to obtain an oxygen demand evaluation value, and determining a method for placing the hydrogel slow-release oxygen material based on the oxygen demand evaluation value, wherein the method includes covering placement and flipping placement; Periodically collect the brightness of the bottom sediment in the target area to obtain the bottom sediment purification evaluation value; When it is determined that the sediment purification does not meet the preset standard according to the sediment purification evaluation value, a distribution characterization value is obtained based on the placement depth of the hydrogel slow-release oxygen material, and the reason why the sediment purification does not meet the preset standard is determined according to the distribution characterization value, or a secondary determination is made as to whether the sediment purification meets the preset standard based on the rate of change of the number of pores on the sediment surface; When it is determined that the purification of the bottom mud meets the preset standards, the dissolved oxygen concentration of the overlying water is collected and the frequency of the hydrogel slow-release oxygen material is corrected according to the rate of change of the dissolved oxygen concentration; Among them, the brightness of the bottom mud is measured using a colorimeter. The brightness of the bottom mud refers to the brightness of the color on the surface of the bottom mud. The sediment purification evaluation value is calculated using the following formula: Where, E represents the sediment purification evaluation value; L1 represents the brightness of the sediment before purification; L0 represents the brightness of the target yellow-brown sediment, and L0 is set to 45; L2 represents the brightness of the sediment measured during the purification process; The method of placing the hydrogel slow-release oxygen material is determined according to the oxygen demand evaluation value of the sediment, wherein: If the oxygen demand evaluation value is less than the preset oxygen demand evaluation value, the coverage delivery method is selected; If the oxygen demand evaluation value is greater than or equal to the preset oxygen demand evaluation value, the flipping delivery method is selected; The process of obtaining the oxygen demand evaluation value of sediment includes: Multiple sampling points are evenly selected within the target area, and sediment of a preset thickness is collected; Insert the probe of the redox potential meter into the bottom mud and record the redox potential value; The arithmetic mean of the redox potential values ​​of all sampling points was recorded as the oxygen demand evaluation value of the sediment; The pore number change rate is the ratio between the pore number after the sediment surface is cleaned and the pore number before the sediment surface is cleaned; The distribution characterization value is the ratio of the placement depth of the hydrogel slow-release oxygen material to the preset depth.

2. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 1, characterized in that: The covering delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate, and a preset delivery frequency; The stirring delivery method is to deliver the hydrogel slow-release oxygen material according to a preset delivery amount, a preset delivery rate and a preset delivery frequency, while stirring the bottom mud in the target area.

3. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 1, characterized in that: The process of determining whether the sediment purification does not meet the preset standards based on the sediment purification evaluation value includes: Obtaining a sediment purification evaluation value based on the brightness of the sediment; Comparing the sediment purification evaluation value with the first preset sediment purification threshold and the second preset sediment purification threshold respectively; If the sediment purification evaluation value is less than the first preset sediment purification threshold, it is determined that the sediment purification does not meet the preset standard, and the reason why the sediment purification does not meet the preset standard is determined based on the distribution characterization value of the gel slow-release oxygen material; If the sediment purification evaluation value is greater than or equal to the first preset sediment purification threshold and less than the second preset sediment purification threshold, it is determined that the sediment purification does not meet the preset standard, and a second determination is made based on the rate of change of the number of pores on the sediment surface whether the sediment purification meets the preset standard; Among them, the first preset sediment purification threshold is less than the second preset sediment purification threshold.

4. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 1, characterized in that: The rate of change of the number of pores on the surface is used to determine whether the sediment purification meets the preset standards. If the pore number change rate is less than the preset pore number change rate, it is determined that the sediment purification does not meet the preset standard, and the amount of hydrogel slow-release oxygen material added is increased according to the difference between the preset pore number change rate and the pore number change rate; If the pore number change rate is greater than or equal to the preset pore number change rate, it is determined that the sediment purification meets the preset standard.

5. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 4, characterized in that: There are several increasing methods for increasing the amount of hydrogel slow-release oxygen material, and each increasing method increases the amount of hydrogel slow-release oxygen material by a different amount; There are several ways to increase the amount of hydrogel slow-release oxygen material, among which: If the pore change difference is less than the first preset pore change difference, the first adjustment coefficient is used to increase the dosage of the hydrogel slow-release oxygen material to a corresponding value; If the pore change difference is greater than or equal to the first preset pore change difference and less than the second preset pore change difference, the second adjustment coefficient is used to increase the dosage of the hydrogel slow-release oxygen material to the corresponding value; If the pore change difference is greater than or equal to the second preset pore change difference, the third adjustment coefficient is used to increase the dosage of the hydrogel slow-release oxygen material to a corresponding value; The pore change difference is the difference between the preset pore number change rate and the pore number change rate.

6. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 3, characterized in that: The reasons why the sediment purification did not meet the preset standards were determined based on the distribution characterization values ​​of the hydrogel slow-release oxygen material, among which, If the distribution characterization value is less than the preset distribution characterization value, it is determined that the reason why the sediment purification does not meet the preset standard is that the hydrogel slow-release oxygen material is suspended and retained in the overlying water, and an early warning is issued; If the distribution characterization value is greater than or equal to the preset distribution characterization value, it is determined that the reason why the purification of the sediment does not meet the preset standard is the uneven delivery of the hydrogel slow-release oxygen material, and the delivery rate of the hydrogel slow-release oxygen material is increased according to the difference between the preset distribution characterization value and the distribution characterization value.

7. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 6, characterized in that: The increase in the delivery rate of the hydrogel slow-release oxygen material is positively correlated with the distribution difference, wherein the distribution difference is the difference between the preset distribution characterization value and the distribution characterization value.

8. The method for treating in-situ sediment using a hydrogel slow-release oxygen material according to claim 7, characterized in that: The frequency of delivery of hydrogel slow-release oxygen material is modified according to the change rate of dissolved oxygen concentration in the overlying water, wherein, If the dissolved oxygen concentration change rate is less than the preset dissolved oxygen concentration change rate, the delivery frequency of the hydrogel slow-release oxygen material does not change; If the dissolved oxygen concentration change rate is greater than or equal to the preset dissolved oxygen concentration change rate, the frequency of adding the hydrogel slow-release oxygen material is reduced according to the difference between the preset dissolved oxygen concentration change rate and the dissolved oxygen concentration change rate.

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