苯并[a]芘污染土壤的植物根际修复研究初探

Study on remediation of Benzoapyrene-contaminated soil by plant rhizosphere

研究了黑麦草(Lolium multiflorumL.)对多环芳烃苯并[a]芘污染土壤的修复作用。研究结果表明,土壤中苯并[a]芘的可提取态wB[a]P随着时间延长而逐渐减少,黑麦草加快了土壤中可提取态苯并[a]芘的减少,提高了苯并[a]P在土壤中的降解率,在1、10、50mg·kg-1苯并[a]芘处理下,黑麦草生长土壤中苯并[a]芘的降解率分别达90.3%、87.5%、78.6%;而没有黑麦草生长土壤中苯并[a]芘的降解率则为79.3%、66.4%、55.6%。黑麦草根际增加土壤中微生物碳的含量,从而提高植物对苯并[a]芘的降解率。植物的地上部也可积累少量苯并[a]芘,但植物对苯并[a]芘的吸收不是黑麦草对其修复的主要机制。土壤自身具有修复苯并[a]芘的潜能,种植黑麦草具有强化土壤修复苯并[a]芘污染的作用。

Benzo[a]pyrene[B[a]P] is one of kind of polycyclic aromatic hydrocarbons [PAHs] that can cause cancer, and was list in the superior pollutant by EPA, USA. B[a]P is a persistence organic pollutant in environment, and the research were main focus on degraded by microorganisms. This paper studied on remediation B[a]P contaminated soil by ryegrass （Lolium multiflorum L.）. The results were showed that the extractable concentration of B[a]P in soil was reduced by time extend, ryegrass enhanced the reduce of B[a]P extractable concentration and increased the degradation rate of B[a]P in soil. In the 1, 10 and 50 mg·kg^-1 B[a]P treatments, the degradation rates of B[a]P with ryegrass were 90.3%, 87.5%, 78.6%, respectively, and without ryegrass were79.3%, 66.4%, 55.6%, respectively. Ryegrass increased the microbiological biomass C and other enzymes activities, so improved the degradation rate of B[a]P, The shoot ofryegrass can accumulate trace of B[a]P, but extract B[a]P by plant is not main mechanisms for remediation B[a]P contaminated soil. Soil itself possess the potential to remediation B[a]P contaminated soil, and plant ryegrass can strengthen the remediation potential for B[a]P contaminated soil.