摘要
用室内模拟培养的方法研究了DDTs在土壤中的老化行为及其在蚯蚓体内的生物富集规律。结果表明。DDTs在土壤中存在老化现象。此类物质在土壤中的可提取态含量随着老化时间延长逐渐降低，并呈现初始老化速率较快，而后老化速率减慢的趋势。在开始的0—30d，其老化的速率较快，o，p’-DDT、p，p’-DDT、o．p’-DDE、p，p’-DDE和p，p’-DDD在土壤中的老化减少量分别是其添加量的53．5％、52．1％、31．4％、36．0％和38．3％。DDTs在蚯蚓体内的生物富集量和生物富集系数也表现出随时间而逐渐降低的趋势，并呈如下规律：p，p＇-DDE〉p，p’-DDD〉o，p’-DDE〉o，p＇-DDT〉p，p＇-DDT。老化虽然可使DDTs的可提取态含量降低。但仍可以在蚯蚓体内有一定的生物富集，潜在的生态风险依然存在。
Aging and bioavailability of DDTs in paddy soil were investigated in the lab under simulated conditions. Results indicate that aging phenomena of DDTs existed in soil. Extractable DDTs decreased as the time elapsed. Its aging rate was rather high at the initial stage, and then slowed down in the rest of the time. During the first 30 days, o,p＇-DDT, p,p＇-DDT, o,p＇- DDE, p,p＇-DDE and p,p＇-DDD dropped by 53.5%, 52.1%, 31.4%, 36.0% and 38.3%, respectively due to high aging rate. DDTs, bioaccumulated in earthworm displayed the same rule as aging, that is, the contents of DDTs in earthworm decreased as the incubation time extended and so did. Bioconcentration factors （BCF） of DDTs in earthworm show a decreasing order of BCF p,p＇-DDE 〉 BCFp.p＇- DDD 〉 BCFo,p＇-VDE 〉 BCFo,p＇-DDT 〉 BCFp,p＇-DDT, Though the extractable DDTs decreased with aging, they still accumulated in earthworms through bioconcentration, and biomagnified through the food chain, thus posing potential environmental risk.
出处
《土壤学报》
CAS
CSCD
北大核心
2007年第1期79-83,共5页
Acta Pedologica Sinica
基金
国家杰出青年基金项目(40325001)
国家重点基础研究发展规划(973)项目(2002CB410805)
安徽省农产品安全重点实验室开放基金(las200505)
安徽高校省级自然科学研究项目(2006KJ175B)资助
