苏南某地区不同土地利用类型下农田土壤的多氯联苯污染现状分析

Analysis of polychlorinated biphenyls pollution status in farmland soils of south Jiangsu under different land-use types

中文关键词:  多氯联苯  土壤  土地利用方式  组成

英文关键词:polychlorinated biphenyls  soil  land-use types  composition

中文摘要:

      目的 探究4种土地利用类型下的苏南地区农田土壤中多氯联苯(polychlorinated biphenyls, PCBs)的含量、组成分布等污染特征。方法 采集苏南某地区的茶园、果园、稻田、菜地4种功能区共87个土壤样品, 运用气相色谱定量分析其PCBs残留特征。结果 研究区域中4种不同土地利用类型下的农田土壤的多氯联苯污染状况存在一定差异, PCBs检出率为菜地>稻田>茶园>果园, 而PCBs总量为稻田>菜地>果园>茶园, 且四者的PCBs同系物组成比例各不相同。其中, 茶园、果园和菜地土壤中PCBs同系物的组成比例具有一定的相似性, 为中氯>高氯>低氯, 而稻田土壤中PCBs同系物的比例为中氯>低氯>高氯。结论 该研究区域不同利用类型下农田土壤中PCBs的含量、组成等污染特征存在差异, 且水稻田的PCBs污染生态风险更高, 高氯化PCBs同系物占比更低, PCBs污染特征呈高度聚类。

英文摘要:

      Objective To explore the influence of the land use types on the content, composition and pollution characteristics of polychlorinated biphenyls (PCBs). Methods PCBs components in 87 surface soil samples were analyzed by gas chromatography, which were collected from farmland soils of 4 land-use types in south Jiangsu, namely tea garden, orchard, paddy field and vegetable plot. Results There were some differences in PCBS pollution in farmland soil of 4 different land-use types in the study area. The detection rate of PCBs were vegetable field>paddy field>tea garden>orchards, and total PCBs paddy field>vegetable field>orchards>tea garden. The compositions of PCBs homologue in soils of 4 different land–use types were different. Among them, the composition of PCBs homologue in the tea plantations, orchards and vegetable soils possessed a certain similarity, which were medium chlorine>high chlorine>low chlorine, while PCBs homologue in paddy soil was medium chlorine>low chlorine>high chlorine. Conclusion In the study area, the contents, compositions and pollution characteristics of PCBs in the farmland soils under different land-use types are different, paddy field presents the higher pollution ecological risk, the lower percentage high chloride PCBs homologue and the PCBs pollution characteristic is highly clustering.