土壤pH、水分及温度对长期污染土壤中苯并a芘动态变化的影响初探

摘要

以受多环芳烃长期污染农田土壤中苯并[a]芘(B[a]P)为研究对象,采用室内模拟试验研究了pH、水分和温度对土壤中B[a]P的动态变化的影响.结果表明,供试污染土壤中B[a]P能被土著微生物快速去除,其消减过程受到pH、水分和温度的影响.初始pH为46、5.9和7.3的泥浆中B[a]P在7天内的去除率分别为43.8％、37.8％和14.0％.在土壤水分为22％、43％、65％和87％田间持水量,温度为28℃条件下培养80天后土壤中B[a]P的去除率分别为42.5％、96.6％、96.3％和34.3％.在土壤pH为4.5,土壤水分为60％±5％田间持水量,温度为25℃和40℃条件下土壤中B[a]P的半衰期分别为33天和16天.可见,pH、水分和温度等环境条件对土壤中B[a]p的消减过程具有明显的影响,可通过人为调控强化B[a]P污染土壤的生物修复.%The effects of soil pH, soil moisture and environmental temperature on the dynamics of benzro[a]pyrene (B[a]P) in long-term contaminated farm land soil were investigated by indoor cultivation. The results showed that B[a]P in soil could be degraded by indigenous microorganisms and the process was influenced greatly by soil pH, soil moisture and environmental temperature. B[a]P in soil was degraded by 43.8%, 37.8% and 14.0% respectively within 7 days' slurry reaction under the conditions of initial pH values of 4.6, 5.9 and 7.3. B[a]P degradation rales were 42.5%, 96.6%, 96.3% and 34.3% within 80 days' incubation under 28℃ with soil moisture of 22%, 43%, 65% and 87% of field water capacity (FWC). The half-time of B[a]P in soil were 33 days and 16 days under the environmental temperature of 25℃ -and 40℃, while soil pH was 4.5 and soil moisture was 60% ±5% of FWC. Therefore, environmental conditions such as soil pH, soil moisture and environmental temperature affected the biodegradation of B[a]P in soil greatly and the degradation of B[a]P could be enhanced by environmental regulation.