广州市新塘镇水环境重金属污染特征研究

为调查广州市新塘镇水环境重金属污染状况,以镇内地表水及东江北干流新塘段为研究对象,对不同样点的20个样中6种重金属进行分析。采用单因子评价法、地质累积指数法对地表水水体、底泥进行污染程度评价,利用潜在生态危害指数法评估底泥中重金属对周围环境的潜在生态危害。结果表明:新塘镇地表水水体中Cu、Zn、Cd、Hg、Cr均达到我国《地表水环境质量标准》(GB3838-2002)三类水质标准,有轻微Pb污染;底泥中重金属污染程度依次为ZnHg、CdPb,其中Zn对环境造成偏重污染,无Cu、Cr污染;潜在生态危害评价法显示底泥中Hg、Cd对环境存在极强生态危害,Zn、Pb、Cr、Cu不构成生态危害。分析底泥中重金属浓度间相关性,表明Hg与Cd、Zn与Cu、Zn与Cd有显著相关。

Characteristics Research of Heavy Metal Pollution in Water Environment of Xintang Town in Guangzhou

In order to investigate the status of heavy metal pollution in water environment of Xintang town in Guangzhou,taking the surface water in the town and the north main stream of Dongjiang in Xintang as the object of study,the 6 kinds of heavy metals in 20 samples from different sampling point are analyzed. The pollution levels of surface water and sediment are evaluated by single factor evaluation assessment and geo-accumulation index method. The potential ecological risk index method is employed to determine the potential ecological risk of heavy metal in sediment on the surrounding environment. The results show that all the levels of Cu,Zn,Cd,Hg,Cr in surface water meet the three kinds of water quality standards in Environment Quality Standard for Surface Water（ GB3838-2002）,but it is slightly contaminated by Pb. The pollution degrees of heavy metals in sediments follow the order Zn Hg,Cd Pb,and environment is heavily contaminated by Zn and not contaminated by Cu and Cr. The potential ecological risk assessment method shows,the sediments are exposed to very high potential ecological risk by Hg and Cd,and low potential ecological risk by Zn、Pb、Cr and Cu. The correlation among the heavy metals＇ concentration in sediment is analyzed,and the result indicates that the Hg and Cd,Cu and Zn,Zn and Cd have significant correlation.