| The paper took a remaining site of fertilizer plant as the research object,set 12 sampling point and got 19 samples of topsoil and deep soils in this area.The paper analyzed the physical and chemical properties of the soils in this site by measuring the pH,cation exchange capacity,organic matter and available sulfur content;and analyzed the pollution of heavy metals by measuring the contents of As,Hg,Cd,Cr,Ni,Sb,V;and assessed the health risk of the soils in this site.The main contents were as follows:(1)The average pH of the soils was 7.87 in this remaining site;The cation exchange capacity of the soils ranged in 18cmol/kg~32cmol/kg,and the average value was23.07cmol/kg,indicated that the ability of remaining the fertility was powerful;The content of organic matter distributed asymmetrically in this site,ranged in 11g/kg~175g/kg and the average value was 43.45g/kg;The content of available sulfur was abundant in the soil,and the average value was 279mg/kg.(2)The results of the Single Factor Index(SFI)showed that: the average contents of heavy metals except Cr in this site were higher than the background values of the soil in Hefei area,and the order of the SFI which were based on the average contents of all the heavy metals was Hg > Cu > Cd > As > Sb > V > Ni > Cr;When we used the Environmental Quality Standard for Soils(GB15618-1995)as the evaluation standard,the samples which were polluted by As,Cu,Cd,Hg were respectively accounted for 42%,21%,21%,5% of all the samples,and the contents of other heavy metals were lower than the standard values.(3)The results of the Nemerow Integrated Pollution Index(NIPI)showed that: when we used the background values of the soil in Hefei area as the evaluation standard,the order of the NIPI about all the 19 samples was 3#soil on the tree root > 8#sediment of the pond > 7# soil in watered ground > 3#topsoil > 6#deep soil > 2’#soil unearthed of the pond > 12#topsoil > 11#topsoil > 1#deep soil > 5#deep soil > 9#topsoil > 7#topsoil >6#topsoil > 5#topsoil > 1#topsoil > 4#topsoil > 10#topsoil > 2’’#soil unearthed of the pond > 2#sectional soil of the pond;When we used the Environmental Quality Standard for Soils(GB15618-1995)as the evaluation standard,10% of all the samples were not polluted,32% of the samples were in emergency,37% of the samples were mildly polluted,16% of the samples were moderately polluted,5% of the samples were seriously polluted.(4)The results of the Cumulative Index(CI)showed that: when we used thebackground values of the soil in Hefei area as the evaluation standard,the order of the CI about the average contents of all the heavy metals was Hg > Cd > Cu > As > V > Sb /Ni >Cr.(5)The results of the Potential Ecological Risk Index(PERI)showed that: when we used the background values of the soil in Hefei area as the evaluation standard,the order of the Potential Ecological Risk Factor about the average contents of all the heavy metals was Hg > Cd > As > Cu > Sb > Ni > V > Cr,and the order of the PERI about all the 19 samples was 8#sediment of the pond > 7# soil in watered ground > 3#soil on the tree root >3#topsoil > 6#deep soil > 2’#soil unearthed of the pond > 11#topsoil > 1#deep soil >7#topsoil > 9#topsoil > 6#topsoil > 5#deep soil > 12#topsoil > 5#topsoil > 1#topsoil >2’’#soil unearthed of the pond > 10#topsoil > 4#topsoil > 2#sectional soil of the pond,53%of all the samples showed moderately potential ecological risk on the local ecological environment,32% of the samples showed serious risk,5% of the samples showed very serious risk;When we used the Environmental Quality Standard for Soils(GB15618-1995)as the evaluation standard,the Potential Ecological Risk Factor about the average contents of all the heavy metals and the PERI of all the samples were all mildly potential ecological risk on the local ecological environment.(6)The results of the Health Risk Assessment showed that: when we considered the maximum and the average contents of all the topsoil samples,V showed unacceptably carcinogenic risk and non-carcinogenic risk on adults,As showed unacceptably carcinogenic risk on adults,and the carcinogenic risk and non-carcinogenic risk of other heavy metals were acceptable.The carcinogenic risk from the exposure via oral ingestion was the maximum,followed the exposure via inhale particulate,and the exposure via dermal contact was the minimum;and the non-carcinogenic risk from the exposure via inhale particulate was the maximum,followed the exposure via oral ingestion,the exposure via dermal contact was the minimum.The risk-based remedial goal calculated for V and As were 6.21 mg/kg and 1.59 mg/kg respectively. |
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