A comprehensive evaluation method for sediment pollution levels

Abstract

This invention provides a comprehensive evaluation method for sediment pollution levels, comprising the following steps: (1) determining monitoring sections and obtaining measured data of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in the sediments; (2) calculating and classifying the heavy metal pollution index based on the measured heavy metal data, and then calculating the comprehensive heavy metal pollution index; (3) evaluating and classifying PAH monomer compounds by combining the PAH sediment quality standard method and the measured PAH data, and then calculating the comprehensive PAH pollution index; (4) calculating the comprehensive sediment pollution index by combining the comprehensive heavy metal pollution index and the comprehensive PAH pollution index, thereby achieving a comprehensive evaluation of sediment pollution levels. The comprehensive evaluation method provided by this invention unifies the heavy metal and PAH indicators, clarifies the weights and standardized values ​​of each pollutant indicator, and ensures the accuracy of the sediment quality evaluation results.

Description

Technical Field

[0001] This invention belongs to the field of environmental pollution assessment technology, and relates to a method for assessing pollution levels, particularly a comprehensive method for assessing sediment pollution levels. Background Technology

[0002] With rapid urbanization and industrialization, large amounts of anthropogenic pollutants, such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), and antibiotics, are discharged into aquatic environments. However, heavy metals and PAHs in aquatic environments are extremely difficult to biodegrade and tend to accumulate in sediments. This can lead to serious harm to biological health at certain concentrations, as PAHs exhibit teratogenic, carcinogenic, and mutagenic effects. Therefore, assessing the risk and pollution levels of pollutants in sediments is of great significance for aquatic ecological environment and pollution control.

[0003] Currently, there are many methods for assessing heavy metal and polycyclic aromatic hydrocarbon (PAH) pollution, such as the geoaccumulation index method, pollution load index method, and potential ecological risk index method, which are commonly used in heavy metal pollution assessment. Although these methods have different backgrounds in classification, they show great similarity in their classification results. In addition, the sediment quality benchmark method, sediment quality standard method, and median effect quotient method are commonly used methods for evaluating PAH monomer compounds. While existing assessment methods perform well in evaluating the pollution levels and ecological risks of single pollutants (such as heavy metals or PAHs) and can be used to assess sediment pollution levels based on the results, they cannot unify heavy metal and PAH indicators to achieve a comprehensive assessment of sediment pollution levels. This leads to a one-sided assessment of sediment pollution levels by different pollution indicators. To achieve unified multi-indicator data and a comprehensive assessment of sediment pollution levels, the key lies in determining the pollution weight of each indicator and standardizing the indicator concentrations.

[0004] Therefore, it is evident that providing a comprehensive evaluation method for sediment pollution levels, unifying heavy metal and polycyclic aromatic hydrocarbon indicators, clarifying the weights and standardized values ​​of each pollutant indicator, and ensuring the accuracy of sediment quality evaluation results have become urgent problems that need to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a comprehensive evaluation method for sediment pollution levels. This comprehensive evaluation method unifies heavy metal and polycyclic aromatic hydrocarbon indicators, clarifies the weight and standardized values ​​of each pollutant indicator, and ensures the accuracy of sediment quality evaluation results.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a comprehensive evaluation method for sediment pollution levels, the comprehensive evaluation method comprising the following steps:

[0008] (1) Determine the monitoring section and obtain measured data on heavy metals and polycyclic aromatic hydrocarbons in the sediment;

[0009] (2) Based on the measured data of heavy metals obtained in step (1), calculate the heavy metal pollution index and classify it, and then calculate the comprehensive heavy metal pollution index.

[0010] (3) Combining the polycyclic aromatic hydrocarbon sediment quality standard method and the measured data of polycyclic aromatic hydrocarbons obtained in step (1), evaluate and classify the polycyclic aromatic hydrocarbon monomer compounds, and then calculate the polycyclic aromatic hydrocarbon comprehensive pollution index.

[0011] (4) Combining the heavy metal comprehensive pollution index obtained in step (2) and the polycyclic aromatic hydrocarbon comprehensive pollution index obtained in step (3), the sediment comprehensive pollution index is calculated, thus achieving a comprehensive evaluation of the sediment pollution level.

[0012] Steps (2) and (3) are not in any particular order.

[0013] This invention establishes a complete comprehensive evaluation system for sediment pollution levels. It combines pollution evaluation methods and results for heavy metals and polycyclic aromatic hydrocarbons (PAHs), and standardizes and weights the indicators in heavy metals and PAHs to calculate the comprehensive sediment pollution index. This system fully considers the comprehensiveness of sediment pollution evaluation and ensures the accuracy of sediment quality evaluation results.

[0014] Preferably, the heavy metal in step (1) includes any one or a combination of at least two of arsenic, cadmium, chromium, copper, nickel, lead, zinc or mercury. Typical but non-limiting combinations include combinations of arsenic and cadmium, cadmium and chromium, chromium and copper, copper and nickel, nickel and lead, lead and zinc, zinc and mercury, arsenic, cadmium and chromium, cadmium, chromium and copper, chromium, copper and nickel, copper, nickel and lead, nickel, lead and zinc, or lead, zinc and mercury.

[0015] Preferably, the polycyclic aromatic hydrocarbons in step (1) include naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, pyrene, etc. Any one or at least two combinations of acenaphthene, fluoranthene, benzo[a]anthene, benzo[a]pyrene, or dibenzo[a,h]anthene, typically but not limitingly including combinations of naphthalene and acenaphthene, acenaphthene and fluorene, fluorene and phenanthrene, phenanthrene and anthracene, anthracene and pyrene, and pyrene and... The combination Combination with acenaphthylene, combination of acenaphthylene and fluoranthene, combination of fluoranthene and benzo[a]anthracene, combination of benzo[a]anthracene and benzo[a]pyrene, combination of benzo[a]pyrene and dibenzo[a,h]anthracene, combination of naphthalene, acenaphthene and fluorene, combination of acenaphthene, fluorene and phenanthrene, combination of fluorene, phenanthrene and anthracene, combination of phenanthrene, anthracene and pyrene, combination of anthracene, pyrene and Combination of pyrene, Combination with acenaphthylene, Combination of acenaphthylene and fluoranthene, combination of fluoranthene, benzo[a]anthracene and benzo[a]pyrene, or combination of benzo[a]anthracene, benzo[a]pyrene and dibenzo[a,h]anthracene.

[0016] Preferably, the calculation formula of the heavy metal pollution index described in step (2) includes:

[0017]

[0018] In the formula, PI i is the pollution index of heavy metal i; C i is the content of heavy metal i; C0 is the background value of heavy metal.

[0019] Preferably, the grading standard described in step (2) is: 0 < PI ≤ 𝟏, no pollution; 1 < PI ≤ 2, no to moderate pollution; 2 < PI ≤ 3, medium pollution; 3 < PI ≤ 4, medium-high pollution; 4 < PI ≤ 5, high pollution.

[0020] Preferably, the calculation formula of the comprehensive heavy metal pollution index described in step (2) includes:

[0021]

[0022] In the formula, HPI is the comprehensive heavy metal pollution index; n is the total number of heavy metal species; C i is the standardized value of heavy metal i; w i is the weight of heavy metal i.

[0023] Specifically, the weight w i of the heavy metal i can adopt W As = 4, W Hg = 4, W Cd = 4, W Cr = 4, W Pb = 4, W Ni = 3, W Cu = 2, W Zn = 2.

[0024] Preferably, the PAH sediment quality standard method described in step (3) divides the concentration of each monomer compound in PAHs into 5 thresholds, which are: rare effect, critical effect, accidental effect, possible effect and frequent effect.

[0025] Specifically, the threshold values ​​for each monomer compound in the polycyclic aromatic hydrocarbons are shown in Table 1 below.

[0026] Table 1

[0027]

[0028] Preferably, the formula for calculating the polycyclic aromatic hydrocarbon pollution index in step (3) includes:

[0029]

[0030] In the formula, PAPI is the comprehensive pollution index of polycyclic aromatic hydrocarbons; n is the total number of polycyclic aromatic hydrocarbon monomer compounds; C j w is the standardized value of monomer compound j; j denoted as the weight of monomer compound j.

[0031] Specifically, the weight w of the monomer compound j j The clustering method was used to determine the order of monomer effect thresholds specified by the sediment quality standard method. The relevant clustering results are shown below. Figure 2 The weights can be referenced from W. Acy =4, W Fluo =4, W Ace =4, W DBA =4, W Ant =4, W Nap =3, W Phe =3, W BaA =3, W Chry =2, W BaP =2, W Flua =1, W Pyr =1.

[0032] Preferably, the calculation formulas for the standardized value of heavy metal i in formula (2) and the standardized value of monomer compound j in formula (3) each independently include:

[0033]

[0034] In the formula, C i T is the standardized value of index i; i S is the enrichment coefficient / concentration of index i; i,k and S i,k+n These are the grading thresholds for the enrichment coefficient / concentration of index i in the k-th and (k+n)-th classes, respectively; I i,k This is the standardized value corresponding to the classification threshold of the enrichment coefficient / concentration of the k-th index.

[0035] Specifically, the I i,k I can be used i,1 =20, Ii,2 = 40, I i,3 = 60, I i,4 = 80, I i,5 = 100, corresponding to the Class I, Class II, Class III, Class IV, and Class V standard values in the surface water environmental quality standards respectively.

[0036] Preferably, the calculation formula of the sediment comprehensive pollution index described in step (4) includes:

[0037]

[0038] In the formula, SPI is the sediment comprehensive pollution index; n is the total number of sediment types; C i and C j correspond to the standard values of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment respectively; w i and w j correspond to the weights of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment respectively.

[0039] Preferably, the criteria for the comprehensive evaluation described in step (4) are: 0 < SPI ≤ 20, very poor; 20 < SPI ≤ 40, poor; 40 < SPI ≤ 60, medium; 60 < SPI ≤ 80, good; 80 < SPI ≤ 100, excellent.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention establishes a complete comprehensive evaluation system for sediment pollution levels, combines the pollution evaluation methods and results of heavy metals and polycyclic aromatic hydrocarbons, and standardizes and weights each index in heavy metals and polycyclic aromatic hydrocarbons to calculate the sediment comprehensive pollution index, fully considering the comprehensiveness of sediment pollution evaluation and ensuring the accuracy of sediment quality evaluation results. Brief Description of the Drawings

[0042] Figure 1 is a schematic flow chart of the comprehensive evaluation method for sediment pollution levels provided by the present invention;

[0043] Figure 2 is a clustering result diagram of the monomer effect threshold specified by the polycyclic aromatic hydrocarbon sediment quality standard method in the comprehensive evaluation method provided by the present invention;

[0044] Figure 3 is a heavy metal comprehensive pollution index result diagram in the comprehensive evaluation method provided in Example 1;

[0045] Figure 4 is a polycyclic aromatic hydrocarbon comprehensive pollution index result diagram in the comprehensive evaluation method provided in Example 1;

[0046] Figure 5 It is the result graph of the sediment comprehensive pollution index in the comprehensive evaluation method provided by Example 1. Specific Embodiments

[0047] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0048] The present invention provides a comprehensive evaluation method for sediment pollution level, as Figure 1 shown, the comprehensive evaluation method includes the following steps:

[0049] (1) Determine the monitoring section and obtain the measured data of heavy metals and polycyclic aromatic hydrocarbons in the sediment; the heavy metals include arsenic, cadmium, chromium, copper, nickel, lead, zinc and mercury, and the polycyclic aromatic hydrocarbons include naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, pyrene, acenaphthylene, fluoranthene, benzo[a]anthracene, benzo[a]pyrene and dibenzo[a,h]anthracene.

[0050] (2) Based on the measured data of the heavy metals obtained in step (1), calculate the heavy metal pollution index and classify it, and then calculate the heavy metal comprehensive pollution index.

[0051] The calculation formula of the heavy metal pollution index includes:

[0052]

[0053] In the formula, PI i is the pollution index of heavy metal i; C i is the content of heavy metal i; C0 is the background value of heavy metal.

[0054] The classification criteria are: 0 < PI ≤ 1, no pollution; 1 < PI ≤ 2, no to moderate pollution; 2 < PI ≤ 3, moderate pollution; 3 < PI ≤ 4, medium-high pollution; 4 < PI ≤ 5, high pollution.

[0055] The calculation formula of the heavy metal comprehensive pollution index includes:

[0056]

[0057] In the formula, HPI is the heavy metal comprehensive pollution index; n is the total number of heavy metal types; C i is the standardized value of heavy metal i; w i is the weight of heavy metal i.

[0058] Specifically, the weight w i of the heavy metal i can adopt W As = 4, W Hg = 4, WCd =4, W Cr =4, W Pb =4, W Ni =3, W Cu =2, W Zn =2.

[0059] (3) Combining the polycyclic aromatic hydrocarbon sediment quality standard method and the measured data of polycyclic aromatic hydrocarbons obtained in step (1), evaluate and classify the polycyclic aromatic hydrocarbon monomer compounds, and then calculate the polycyclic aromatic hydrocarbon comprehensive pollution index.

[0060] The polycyclic aromatic hydrocarbon (PAH) sediment quality standard method divides the concentration of each monomer compound in PAHs into 5 thresholds: rare effect, critical effect, accidental effect, possible effect, and frequent effect.

[0061] The formula for calculating the polycyclic aromatic hydrocarbon (PAH) comprehensive pollution index includes:

[0062]

[0063] In the formula, PAPI is the comprehensive pollution index of polycyclic aromatic hydrocarbons; n is the total number of polycyclic aromatic hydrocarbon monomer compounds; C j w is the standardized value of monomer compound j; j denoted as the weight of monomer compound j.

[0064] Specifically, the weight w of the monomer compound j j The clustering method was used to determine the order of monomer effect thresholds specified by the sediment quality standard method. The relevant clustering results are shown below. Figure 2 The weights can be referenced from W. Acy =4, W Fluo =4, W Ace =4, W DBA =4, W Ant =4, W Nap =3, W Phe =3, W BaA =3, W Chry =2, W BaP =2, W Flua =1, W Pyr =1.

[0065] The standardized values ​​of heavy metal i in formula (2) and the standardized values ​​of monomeric compound j in formula (3) are calculated independently, respectively:

[0066]

[0067] In the formula, C i T is the standardized value of index i; i S is the enrichment coefficient / concentration of index i;i,k and S i,k+n are the classification thresholds of the enrichment coefficients / concentrations of the k-th and (k + n)-th type of indicators corresponding to the indicator i respectively; I i,k is the standardized value corresponding to the classification threshold of the enrichment coefficient / concentration of the k-th type of indicator.

[0068] Specifically, the I i,k can adopt I i,1 = 20, I i,2 = 40, I i,3 = 60, I i,4 = 80, I i,5 = 100, corresponding to the standardized values of Class I, Class II, Class III, Class IV and Class V in the surface water environmental quality standards respectively.

[0069] (4) Combine the heavy metal comprehensive pollution index obtained in step (2) and the polycyclic aromatic hydrocarbon comprehensive pollution index obtained in step (3) to calculate the sediment comprehensive pollution index, that is, realize the comprehensive evaluation of the sediment pollution level.

[0070] The calculation formula of the sediment comprehensive pollution index includes:

[0071]

[0072] In the formula, SPI is the sediment comprehensive pollution index; n is the total number of sediment types; C i and C j are respectively the standardized values of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment; w i and w j are respectively the weights of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment.

[0073] The criteria for the comprehensive evaluation are: 0 < SPI ≤ 20, very poor; 20 < SPI ≤ 40, poor; 40 < SPI ≤ 60, medium; 60 < SPI ≤ 80, good; 80 < SPI ≤ 100, excellent.

[0074] Among them, steps (2) and (3) have no sequence.

[0075] Example 1

[0076] This example provides a comprehensive evaluation method for the sediment pollution level. As Figure 1 shown, the comprehensive evaluation method includes the following steps:

[0077] (1) Select 24 river sections of the main stream and tributaries of the Yangtze River during the normal water period. The measured heavy metal and polycyclic aromatic hydrocarbon indicators include arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, pyrene, Acenaphthene, fluoranthene, benzo[a]anthene, benzo[a]pyrene, and dibenzo[a,h]anthene, a total of 20 indicators.

[0078] (2) The heavy metal pollution index is calculated using formula (1) and combined with the polycyclic aromatic hydrocarbon concentration to form a dataset. Due to space limitations, only a portion of the data is selected in this embodiment, as shown in Table 2 below.

[0079] Table 2

[0080]

[0081] The heavy metal pollution index (HPI) was calculated using formula (2), and the relevant calculation results are shown in [reference needed]. Figure 3 .

[0082] (3) Based on the classification criteria of polycyclic aromatic hydrocarbon monomers in Table 1 and the concentration of polycyclic aromatic hydrocarbon monomers obtained in step (1), the polycyclic aromatic hydrocarbon monomer compounds are evaluated and classified. Then, the polycyclic aromatic hydrocarbon comprehensive pollution index (PAPI) is calculated using formula (3). The relevant calculation results are shown in [reference to table 1]. Figure 4 .

[0083] (4) Combining the heavy metal comprehensive pollution index HPI obtained in step (2) and the polycyclic aromatic hydrocarbon comprehensive pollution index PAPI obtained in step (3), the sediment comprehensive pollution index SPI is calculated using formula (5). The relevant calculation results are shown in [reference]. Figure 5 This means achieving a comprehensive assessment of sediment pollution levels.

[0084] Therefore, this invention establishes a complete comprehensive evaluation system for sediment pollution levels. It combines pollution evaluation methods and results for heavy metals and polycyclic aromatic hydrocarbons, and standardizes and weights the indicators in heavy metals and polycyclic aromatic hydrocarbons to calculate the comprehensive sediment pollution index. This fully considers the comprehensiveness of sediment pollution evaluation and ensures the accuracy of sediment quality evaluation results.

[0085] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A comprehensive evaluation method for sediment pollution levels, characterized in that, The comprehensive evaluation method includes the following steps: (1) Determine the monitoring sections and obtain the measured data of heavy metals and polycyclic aromatic hydrocarbons in the sediment; (2) Based on the measured data of heavy metals obtained in step (1), calculate the heavy metal pollution index, classify it, and then calculate the comprehensive heavy metal pollution index; (3) Combine the sediment quality standard method of polycyclic aromatic hydrocarbons and the measured data of polycyclic aromatic hydrocarbons obtained in step (1), evaluate and classify the individual polycyclic aromatic hydrocarbon compounds, and then calculate the comprehensive polycyclic aromatic hydrocarbon pollution index; (4) Combine the comprehensive heavy metal pollution index obtained in step (2) and the comprehensive polycyclic aromatic hydrocarbon pollution index obtained in step (3) to calculate the comprehensive sediment pollution index, that is, to achieve the comprehensive evaluation of the sediment pollution level; The calculation formula of the comprehensive heavy metal pollution index described in step (2) includes: In the formula, HPI is the comprehensive heavy metal pollution index; n is the total number of heavy metal species; C i w represents the standardized value of heavy metal i in the sediment. i The weight of heavy metal i in the sediment; The calculation formula of the comprehensive polycyclic aromatic hydrocarbon pollution index described in step (3) includes: In the formula, PAPI is the comprehensive pollution index of polycyclic aromatic hydrocarbons; n is the total number of polycyclic aromatic hydrocarbon monomer compounds; C j w is the standardized value of polycyclic aromatic hydrocarbon monomer compound j in the sediment; j The weight of polycyclic aromatic hydrocarbon monomer compound j in the sediment; The calculation formulas of the standardized value of heavy metal i in formula (2) and the standardized value of individual compound j in formula (3) are both: In the formula, C i ’ T is the standardized value of index i; i S is the enrichment coefficient / concentration of index i; i,k and S i,k+n These are the grading thresholds for the enrichment coefficient / concentration of index i in the k-th and (k+n)-th classes, respectively; I i,k This is the standardized value corresponding to the classification threshold of the enrichment coefficient / concentration of the k-th index; Among them, steps (2) and (3) have no sequential order.

2. The comprehensive evaluation method according to claim 1, characterized in that, The heavy metals described in step (1) are selected from any one or a combination of at least two of arsenic, cadmium, chromium, copper, nickel, lead, zinc or mercury.

3. The comprehensive evaluation method according to claim 1, characterized in that, The polycyclic aromatic hydrocarbons mentioned in step (1) are selected from naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, pyrene, etc. Any one or a combination of at least two of acenaphthene, fluoranthene, benzo[a]anthene, benzo[a]pyrene or dibenzo[a,h]anthene.

4. The comprehensive evaluation method according to claim 1, characterized in that, The calculation formula of the heavy metal pollution index described in step (2) includes: In the formula, PI i The pollution index of heavy metal i; c i c0 represents the content of heavy metal i; c0 represents the background value of heavy metals.

5. The comprehensive evaluation method according to claim 1, characterized in that, The classification criteria in step (2) are: 0 < PI ≤ 1, no pollution; 1 < PI ≤ 2, no to moderate pollution; 2 < PI ≤ 3, medium pollution; 3 < PI ≤ 4, medium-high pollution; 4 < PI ≤ 5, high pollution.

6. The comprehensive evaluation method according to claim 1, characterized in that, The sediment quality standard method of polycyclic aromatic hydrocarbons in step (3) divides the concentration of each individual polycyclic aromatic hydrocarbon compound into 5 thresholds, namely rare effect, critical effect, accidental effect, possible effect and frequent effect.

7. The comprehensive evaluation method according to claim 1, characterized in that, The calculation formula of the comprehensive sediment pollution index described in step (4) includes: In the formula, SPI is the comprehensive sediment pollution index; n is the total number of sediment species; C i and C j These correspond to the standardized values ​​of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment, respectively; w i and w j These correspond to the weights of heavy metal i and polycyclic aromatic hydrocarbon monomer compound j in the sediment, respectively.

8. The comprehensive evaluation method according to claim 1, characterized in that, The comprehensive evaluation criteria in step (4) are: 0 < SPI ≤ 20, very poor; 20 < SPI ≤ 40, poor; 40 < SPI ≤ 60, medium; 60 < SPI ≤ 80, good; 80 < SPI ≤ 100, excellent.

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