高州农田土壤中邻苯二甲酸酯污染特征与形态分析

Evaluation of PAEs Pollution of Farmland Soil in Gaozhou

对农田土壤中邻苯二甲酸酯的水平与垂直分布、以及存在形态进行了调查分析。结果表明,15个样品中DMP、DEP、DBP单因子污染指数分别为4.3~27.8、0.3~4.7、0.9~26.5,存在超标情况,且DMP含量全部超标,BBP、DEHP和DOP的单因子污染指数均小于1,符合控制标准值要求。土壤样品综合污染指数在3.8~20.0,属于严重污染。DMP和DOP主要存在于耕作层(0~20 cm),DBP和DEHP在0~60 cm的各层中均存在,表明后者垂向迁移能力较强。土壤中PAEs可脱附态的主要种类为DBP、DEHP、DMP,有机溶剂提取态、结合残留态的主要种类为DEHP、DBP;可脱附态、有机溶剂提取态、结合残留态所占比例约为32%~56%、13%~29%、29%~39%。

The vertical distribution and exist ing forms of PAEs in the farmland soil were investigated. The results showed that the content of DMP, DEP and DBP in 15 samples were exceed the standard, and the single factor pollution index of the PAEs were 4.3- 27.8, 0.3- 4.7 and 4.7- 26.5 respectively. The single factor pollution index of BBP, DEHP and DOP were below 1 and meet standard requirements. The comprehensive pollution index of the PAEs was in the range of 3.8- 20.0, which belongs to the serious pollution status. DMP and DOP mainly existed in surface soil(0- 20 cm), while DBP and DEHP in 0- 60 cm layer, The finding shows that the latter had a strong ability of vertical migration. The extractable forms of PAEs in soil were DBP, DEHP and DMP, DEHP and DBP, while the proportions of three forms were about 32%- 56%, 13%- 29% and 29%- 39%, respectively.