某电子废弃物拆卸区土壤、水和农作物中砷含量状况研究

Arsenic Contents in Soil,Water,and Crops in an E-waste Disposal Area

为研究电子废弃物拆卸、废旧金属冶炼等是否对周围环境造成砷积累和污染,选取浙江省台州路桥区为调查对象,通过测定在该区采集的水、沉积物、土壤以及稻米和蔬菜中的砷,以了解该地区环境中砷的含量特征和潜在风险,并对土壤-水稻系统砷的分布和吸收转运规律进行了初步分析.结果表明,地表水和地下水砷含量平均值分别为8.26μg/L和18.52μg/L,部分地下水超过WHO推荐的饮用水标准(10μg/L),但没有超过我国相关环境标准Ⅲ级限值(50μg/L).沉积物砷含量平均值为9.62mg/kg.水田土壤和菜地砷含量平均值分别为7.11 mg/kg和6.17 mg/kg,均在一级标准范围内,该区农田土壤总体上未受砷的污染.糙米和蔬菜中的砷平均值分别为165.1μg/kg和144.2μg/kg,均未超过我国规定的食品卫生标准.土壤-米糠-糙米中砷含量之间相关性显著.冶炼源周围的土壤和米糠中砷含量较其他源高,可能已经对周围土壤-水稻砷积累产生影响.

In order to study whether disposing electronic wastes and secondary metal smelting could cause an arsenic pollution in the environment or not,Luqiao town,Taizhou City,Zhejiang Province was selected as a study area.The main purpose of this paper was to characterize arsenic contents in the local environment,including waters,sediments,soils and rice,and to assess the potential risk to humans. Additionally,the arsenic spatial distribution property and arsenic uptake-translocation rule in soil-rice system were also studied.The results showed that the average arsenic levels in the surface water and the groundwater were 8.26 μg/L and 18.52μg/L,respectively,which did not exceed the limiting value of Chinese Environment Standards class Ⅲ.Whereas,some groundwater exceeded the recommended standard by the WHO for drinking water（10μg/L）.The arsenic（on average 7.11mg/kg） in paddy soils and arsenic（on average 6.17mg/kg） in the vegetable garden soils were lower than the value recommended by the National Standard（level Ⅰ）.The average arsenic contents in brown rice and husks were 165.1μg/kg and 144.2μg/kg,which was also lower than the Chinese Foods Quality Standard.The arsenic contents between the corresponding soils-rice and husks-brown rice showed significantly positive correlations.By comparison,the arsenic contents of soils and husks collected around electroplating were relatively higher than most of other pollutant sources,indicating the electroplating may lead accumulation of arsenic in the paddy soil-rice system.