华南电子垃圾回收区农田土壤重金属污染及其化学形态分布  

Heavy metal contaminations and chemical speciation of farmland soils in an e-waste recycling town in South China

作　　者：张朝阳[1,2,3] 彭平安[1] 刘承帅[2] 宋建中[1] 毕新慧[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]广东省生态环境与土壤研究所,广东广州510650 [3]中国科学院大学,北京100049

出　　处：《生态环境学报》2012年第10期1742-1748,共7页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(40801086);广东省科学院分析测试基金项目(SF2008-54);广州地区分析测试基金专题项目(201010)

摘　　要：广东清远龙塘镇作为电子垃圾回收地区,已从事电子垃圾处置超过30年,可能给当地的农田土壤带来了严重的风险。为评价龙塘农田土壤中重金属污染程度,采集28个农田土壤样品,用于研究As、Cd、Co、Cr、Cu、Hg、Ni、Pb、Sn、Zn10种重金属含量及其不同存在形态。结果表明,与中国食用农产品产地环境质量标准比较,大多数当地农田土壤已在不同程度上受到重金属污染,85.7%的土壤样品中有一种或多种重金属的含量超过了相应的评价标准值。化学形态分析结果表明,除Hg外,人为来源的其她重金属更多地进入了可迁移形态部分(弱酸可溶态+可还原态+可氧化态),从而具有更高的毒害性和生物有效性,该电子垃圾处置区农田土壤已基本不适于食用农产品种植。大多数重金属在0.05或0.01水平上具有显著的相关性,这表明龙塘镇土壤重金属污染主要来源于不受控制的电子垃圾回收活动。对中国或其他国家具有类似的粗放式电子垃圾回收处置地区来说,有关龙塘镇农田土壤中重金属污染水平及其潜在的生物毒害性研究具有代表性意义。The recycling of electronic-waste （e-waste） in Longtang, China, a town intensively involved in e-waste processing for more than 30 years, may present a significant farmland soil risk. To evaluate the extent of heavy metal concentrations in farmland soils in Longtang, 28 farmland soil samples were taken for 10 heavy metals （As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sn and Zn） contamination and different existing forms study. It was found that most farmland soils in Longtang were contaminated to various extents by heavy metals when referred to Chinese farmland environmental quality evaluation standards for edible agricultural products. 85.7% of the soil samples contained one or more kinds of heavy metals with higher concentrations than the corresponding standard values. The chemical partitioning results suggested that except of Hg, more of the other anthropogenic heavy metals into the mobile fractions （acid exchangeable ＋ reducible ＋ oxidisable） and were high toxic and bioavailability in the farmland soils, and the farmland soils were not suitable for edible food plant in this e-waste recycling area. Most of the heavy metals were correlated well with each other at the 0.05 or 0.01 levels, which indicated the single source of the heavy metal contamination from uncontrolled e-waste recycling activities in Longtang town. The heavy metal contamination levels and the potential toxicity for crops plant in Longtang may serve as a representative study for other e-waste recycling sites in China or other countries involved in similar crude recycling activities.

关 键 词：农田土壤 电子垃圾 重金属污染 化学形态 BCR法 

分 类 号：X131.3[环境科学与工程—环境科学]