新疆温宿县土壤重金属含量分布及污染风险评价

发布时间：2017-12-30 18:38

  本文关键词：新疆温宿县土壤重金属含量分布及污染风险评价　出处：《新疆农业科学》2016年12期 　论文类型：期刊论文

  更多相关文章： 土壤 重金属 污染评价 生态风险

【摘要】：【目的】分析新疆温宿县林果土壤重金属As、Hg、Cd、Pb和Cr的含量,明确该区域的重金属含量及分布状况,并对其安全性进行风险评价。【方法】2014年对温宿县5.33×104hm2(80万亩)林果取样调查,根据林果分布、树龄及土壤特征在1 300个样点中选取代表性138个样点,测定重金属As、Hg、Cd、Pb和Cr的总含量。采用污染指数法和潜在生态风险指数法,结合新疆土壤背景值、国家土壤质量二级标准,进行该区的土壤重金属总量分析和重金属污染评价。【结果】温宿县土壤重金属,As平均含量11.96 mg/kg,Hg平均含量0.032 mg/kg,Cd平均含量0.17 mg/kg,Pb平均含量22.93 mg/kg,Cr平均含量43.38 mg/kg,且5种土壤重金属变异系数均较小。以国家土壤环境质量标准(二级)为基础,各元素的污染指数污染程度排序为:AsCdCrPbHg。污染评价表明,5种重金属元素(As、Hg、Cd、Pb和Cr)在温宿县土壤的单因子污染指数(Pi)中,均属于安全等级(Pi≤1),为清洁水平;就综合污染指数(Ps)而言,该区域的土壤重金属元素污染程度也均属于安全等级(Px≤0.7),为清洁水平;单因子潜在生态风险评价指数的平均值表明,温宿县5种重金属的潜在生态危害排序为:Hg(77.35)Cd(42.60)As(11.03)Pb(7.96)Cr(1.01),重金属As、Pb和Cr处于低生态风险程度(Eir40),重金属Hg和Cd处于中生态风险程度(Eir80)。5种重金属的综合潜在生态风险指数的范围为79.78~236.10,处于低生态风险程度(RI=139.94150)。【结论】新疆温宿县土壤重金属(As、Hg、Cd、Pb和Cr)含量均低于警戒线,污染程度均处于安全等级,单因子、综合生态风险评价也均属于低生态风险程度,说明温宿县的土壤环境质量整体良好。
[Abstract]:[objective] to analyze the contents of Pb and Cr in the forest and fruit soil of Wensu County, Xinjiang, and to determine the content and distribution of heavy metals in this area. In 2014, 5.33 脳 10 ~ 4 hm ~ 2 (800,000 mu) forest and fruit were sampled and investigated according to the distribution of forest and fruit. The age of trees and soil characteristics were determined by selecting 138 typical sites from 1 300 sites. Total content of Pb and Cr. Using pollution index method and potential ecological risk index method, combining the soil background value of Xinjiang, the national soil quality secondary standard. The total amount of heavy metals and the assessment of heavy metal pollution were analyzed in this area. [results] the average content of heavy metals and as in Wenshu County was 11.96 mg/kg. The average content of Hg is 0.032 mg / kg ~ (-1) CD 0.17 mg / kg ~ (-1) Pb is 22.93 mg/kg. The average content of Cr was 43.38 mg / kg, and the coefficient of variation of heavy metals in the five soils was small, which was based on the National soil Environmental quality Standard (grade II). The pollution index of each element is in the order of the pollution degree of 1: AsCdCrPbHg. The pollution evaluation shows that there are five heavy metal elements in the plant. In the single factor pollution index (Pii) of soil in Wenshu County, Pb and Cr belong to the safety grade of Pi 鈮，

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