珠江三角洲污灌区地下水重金属含量及其相互关系

Content and Relationship of Heavy Metals in Groundwater of Sewage Irrigation Area in Pearl River Delta

为了解污灌区地下水重金属含量特征,采集地表水样5组、地下水样14组进行化学组分定量分析。结果表明:污灌区地下水8种重金属元素中,仅有Ni和As两种元素超标,超标率分别为14.3%和42.9%。8种重金属含量在污灌区地表水、工厂废水以及地下水中存在明显的对应关系。Ni、Zn、Se、Cd这4种元素间存在显著或极显著的正相关关系,Cu与Pb和Cd分别呈极显著和显著的正相关关系,Cr仅与Ni呈显著的正相关关系,As与其它7种元素的相关性均不明显。聚类分析结果显示8种重金属可分为4类:Pb和Cu一类,Se、Cd、Ni、Zn一类,Cr和As均单独一类。Pb和Cu与Fe的相似性最好,Se、Cd、Ni、Zn与Mg2+存在较好的相似性,Cr与HCO3-的相似性最好,As与SO24-存在一定的相似性。

The research investigated the distribution and correlation of heavy metals in groundwater of sewage irrigation area in Pearl River Delta.14 groundwater samples and five surface water samples were collected in August 2008,and the groundwater samples were filtrated through 0.45 μm membranes in the field site.The results showed that the amount of Ni and As in some groundwater samples exceeded the standards for drinking water quality in China,and the over standard rates were 14.3% and 42.9%,respectively.The concentration of Cr,Pb,Cu,Zn,Se and Cd in all groundwater samples was lower than the upper limits for drinking water quality in China.There was a good relationship between the contents of these eight heavy metals in surface water,industrial wastewater and groundwater of sewage irrigation area.Furthermore,there was a significant or remarked significant positive correlation between Cd,Cu,Zn and Pb in groundwater,a remarked significant positive correlation between Cu and Pb in groundwater,a remarkable positive correlation between Cu and Cd in groundwater,a significant positive correlation between Cr and Ni in groundwater and no significant correlation between As and other seven heavy metals.The result of cluster analysis showed that these eight heavy metals can be divided into four categories： Pb and Cu;Se,Cd,Ni and Zn;Cr;As.Pb and Cu had a good similarity with Fe.Se,Cd,Ni and Zn had a good similarity with Mg2＋.Cr and HCO-3 had a good similarity,and As and SO2-4 had a certain similarity