【摘要】 为了解三江平原农田、退耕还湿地、天然草本沼泽土壤中重金属含量和农药残留状况,以黑龙江省抚远市乌苏镇东兴村为研究区,采集农田、退耕还湿地和天然草本沼泽土壤样品,分析了这些土壤中重金属含量和农药残留量;采用潜在生态风险指数法和风险商值法,分别评价了土壤中的重金属潜在生态风险水平和农药残留潜在生态风险水平。研究结果表明,研究区土壤中As、Cd、Cr、Ni和Cu的平均含量都低于国家土壤环境质量二级标准(GB15618—1995);农田土壤中的As、Cd、Cr、Cu和Ni平均质量比分别为12.4 mg/kg、0.24 mg/kg、97.06mg/kg、24.08 mg/kg和36.46 mg/kg,退耕还湿地土壤中的Cr和Ni平均质量比为95.13 mg/kg和31.43 mg/kg。农田、退耕还湿地和天然草本沼泽土壤中的滴滴涕残留以4.4’—滴滴伊为主,其4.4’—滴滴伊平均残留质量比分别为6.13 ng/g、6.80 ng/g和4.47 ng/g;农田土壤中检测出阿特拉津平均残留质量比达到了79.32 ng/g;农田土壤中的Cd含量达到了中等潜在生态风险水平;农田、退耕还湿地和天然草本沼泽土壤中5种重金属综合潜在生态风险处于轻度潜在生态风险水平;农田土壤中残留的阿特拉津的污染风险商大于1,说明阿特拉津残留可能有潜在的生态风险。更多还原

【Abstract】 In order to explore the content of heavy metals and the residual condition of pesticide residue in the farmland soil, reverting farmland to wetland soil and natural marsh soil, the three types of soil in the areas of Dongxing Village of Wusu Town, Fuyuan City, Heilongjiang Province were collected. The content of heavy metals and the pesticide residue in soils were analyzed, and evaluated by the methods of potential ecological risk and risk quotient(RQ), respectively. The results showed that the average contents of As, Cd, Cr, Ni and Cu in the three types of soils were lower than the secondary standard of national soil environmental quality(GB15618—1995). The average contents of heavy metals As, Cd, Cr, Cu and Ni in the farmland soils were12.4 mg/kg, 0.24 mg/kg, 97.06 mg/kg, 24.08 mg/kg and 36.46 mg/kg, as well as the average contents of heavy metals Cr and Ni were 95.13 mg/kg and 31.43 mg/kg in the reverting farmland to wetland soils.Dichlorodiphenyltrichloroethane(DDT) in the farmland soils, the reverting farmland to wetland soils and the natural marsh soils was dominated by 4.4’-DDE residue, and the average contents of 4.4’-DDE were 6.13 ng/g,6.8 ng/g and 4.47 ng/g, respectively. The average level of atrazine in the farmland soils was detected to be79.32 ng/g. The potential ecological risk of Cd in the farmland soils in the study areas reached a medium level. The comprehensive potential ecological risk of five heavy metals in the farmland soils, the reverting farmland to wetland soils and the natural marsh soils were at a mild level. The risk quotient of atrazine in the farmland soils was greater than 1, indicating that atrazine residues might have potential ecological risks.更多还原