土壤的老化对PCB138的可提取性和生物可利用性的影响

范小欢; 单振华; 杨腾飞; 严静娜; 任源

文章摘要

范小欢,单振华,杨腾飞,严静娜,任源.土壤的老化对PCB138的可提取性和生物可利用性的影响[J].农业环境科学学报,2016,35(5):919-925.

土壤的老化对PCB138的可提取性和生物可利用性的影响

Effect of aging on extractability and bioavailability of PCB138 in soils

投稿时间：2015-11-03

DOI：10.11654/jaes.2016.05.015

中文关键词: PCBs 生物可利用性提取率蚯蚓

英文关键词: PCBs bioavailability extractability earthworms

基金项目:国家自然科学基金项目(51178190);广州市科信局应用基础研究项目(2013J4100107);广东省教育厅学科建设专项资金项目(2013CXZD A004)

作者	单位	E-mail
范小欢	华南理工大学环境与能源学院, 广州 510006
单振华	华南理工大学环境与能源学院, 广州 510006
杨腾飞	华南理工大学环境与能源学院, 广州 510006
严静娜	华南理工大学环境与能源学院, 广州 510006
任源	华南理工大学环境与能源学院, 广州 510006 工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006	ceyren@scut.edu.cn

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中文摘要:

为探讨老化行为对多氯联苯(Polychlorinated biphenyls, PCBs)在土壤中的可提取性和生物可利用性的影响,选取2,2',3,4,4',5-六氯联苯(PCB138)作为目标污染物,进行90 d的老化试验,比较了超纯水提取、正丁醇溶液提取、超声提取(正己烷/丙酮)和索氏抽提(正己烷/二氯甲烷)等4种方法对土壤中不同老化时间PCB138的提取率;以赤子爱胜蚓(Eisenia fetida)为土壤模式参照生物,在不同的老化时间里测定蚯蚓体内PCB138的含量与脂肪含量。结果表明,4种方法提取PCB138的能力依次为索氏抽提(正己烷/二氯甲烷)≈超声提取(正己烷/丙酮)>正丁醇提取>超纯水溶液提取;索氏抽提、超声提取和正丁醇溶液提取的提取率从最初的87%~93%、85%~90%、50%~60%分别下降到70%~76%、65%~73%、25%~45%,在30~45 d时总提取量保持稳定,而超纯水提取PCB138的量有限,显示出最低的提取能力且为非重复性结果。PCB138在蚯蚓体内富集量随接触时间增加而增加,在老化30 d左右其体内PCB138富集量最大;在老化30~60 d时,蚯蚓体内的PCB138的含量逐渐下降,健康状况良好的蚯蚓脂肪含量有所下降但不明显。正丁醇溶液提取、超声提取和索氏抽提对PCB138的提取率,以及老化土壤中蚯蚓对PCB138的富集量,均说明PCB138在土壤中的生物有效性随着老化时间的延长而降低。

英文摘要:

Once entering soil, polychlorinated biphenyls(PCBs) are adsorbed by or bonded with soil components, which may reduce their movements. Therefore, aging time would affect extractability and bioavailability of PCBs in the soil. A 90 day aging study was conducted to estimate the extraction efficiencies of PCB138 by four extracting agents and to access Eisenia fetida's responses. Results showed that the extraction efficiencies were in order of ultra sonic≈soxhlet>n-butanol>pure water. The extraction rates of PCB138 over time were decreased from 87%~93%, 85%~90%, and 50%~60% to 70%~76%, 65%~73%, and 25%~45%, for soxhlet, ultra sonic, and n-butanol, respectively. The total extraction amount of PCB138 became stable after 30~45 days. However, the PCB138 amount extracted by pure water was small. The amount of PCB138 accumulation in E. fetida increased with increasing of contacting time and reached the maximum in 30 days. The fat content in E. fetida increased during the first 30 days but decreased a little during 30~60 days. These results demonstrated that the extractability of PCB138 by n-butanol, US, and Soxhlet extraction decreases over aging and the bioavailability to earthworms also decreases.

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