北京地区池塘底泥中重金属分布及其污染评价

目的针对北京地区17家养殖池塘底泥中重金属污染状况进行调查及评价重金属生态风险,为水产养殖环境提供理论依据并指导生产。方法使用原子吸收分光光度法测定底泥中Cu、Zn、Cr、Pb、Cd含量,用原子荧光分光光度法测定底泥中Hg、As含量;采用单项污染指数、综合污染指数法及Hakanson潜在生态风险评价方法对养殖池塘底泥中重金属的污染状况分别进行评价。结果 17家池塘底泥中重金属Cu、Zn、Cr、Pb、Cd、As的平均含量分别为17.85、50.27、33.09、14.50、0.06和1.98mg/kg(均以湿基计),Hg未检出;Zn、Pb、Cd、Hg和As处于安全等级,Cu污染处于警戒线,Cr污染处于轻度污染;底泥中重金属的潜在生态风险顺序依次CdCuPbAsCrZn,潜在生态风险危害程度轻微。结论北京地区17家养殖场池塘底泥中重金属含量的蓄积对养殖水产品质量影响较小,适宜水产养殖。

Distribution and pollution assessment of heavy metals in sediments of aquaculture ponds in Beijing area

Objective To investigate 7 kinds of representative heavy metals distribution and analyze the potential ecological risk of heavy metals in the sediments of aquaculture ponds in Beijing area in order to provide references for aquaculture environment rationally. Methods The contents of Cu, Zn, Cr, Pb, and Cd were determined by atomic absorption spectroscopy in sediments, and the contents of Hg and As were determined by atomic fluorescence spectrum. The ecological risk assessment was evaluated using single pollution index, Nemerow integrated index and Hakanson potential ecological risk analysis. Results The average content results of Cu, Zn, Cr, Pb, Cd, and As were 17.85, 50.27, 33.09, 14.50, 0.06 and 1.98 mg/kg, respectively, and Hg was not detected. Zn, Pb, Cd, Hg, and As in the sediments of aquaculture ponds were at the safe and clean level, while Cu was at alert level and Cr was at slightly polluted level. The potential ecological risk of heavy metals ranked as Cd>Cu>Pb>As>Cr>Zn, and all of the heavy metals in sediments indicated a mild polluting level. Conclusion The accumulation of heavy metals content have little impact on the quality of aquaculture products in the 17 representative sediments of aquaculture ponds and they are suitable for aquaculture.