活性炭对土壤中多环芳烃生物有效性的影响

Effect of Activated Carbon on Bioavailability of Polycyclic Aromatic Hydrocarbons in Soil

在某场地采集不同土层土壤,通过室内培养试验,研究添加5%(m/m)活性炭对土壤中PAHs残留的影响,并利用羟丙基-β-环糊精提取方法评价土壤中PAHs生物有效性的动态变化。结果表明:在8个月内,添加活性炭处理土壤中菲、芘的残留量显著高于对照处理,苯并[b]荧蒽的残留量显著低于对照处理,苯并[g,h,i]芘残留量在两处理之间无显著差异。在第1个月时,活性炭处理土壤中菲、芘、苯并[b]荧蒽生物有效性较对照处理分别降低了35.06%、37.73%、39.60%,苯并[g,h,i]芘生物有效性仅降低了1.37%;随着时间延长活性炭对土壤中PAHs生物有效性的阻控效果呈减弱趋势。因此,土壤添加5%活性炭能够有效降低PAHs生物有效性,减少其环境风险,并且在添加活性炭1个月内阻控效果最佳。

Soils in different depths were collected in a site, the effect of adding 5%(m/m)activated carbon on polycyclic aromatic hydrocarbons(PAHs) residues in soils was studied by an incubation experiment, and the changes of bioavailability of PAHs in soils was evaluated using the hydroxypropyl-β-cyclodextrin extraction method. The results show that the residues of phenanthrene,pyrene and benzo[b]fluoranthene in the soils treated with activated carbon are significantly higher than in the control treatment,but there is no significant difference in the residues of benzo[g,h,i]pyrene in soils between the two treatments within eight months.During the first month, the bioavailability of phenanthrene, pyrene and benzo[b]fluoranthene in activated carbon treatment are decreased by 35.06%, 37.73% and 39.60%, respectively compared with the control treatment, and the bioavailability of benzo[ghi]pyrene is decreased by only 1.37%. With the extension of incubation time, the inhibition effect of activated carbon on PAHs bioavailability in soil is decreased. Therefore, this study shows that amending 5% activated carbon can effectively reduce the bioavailability and environmental risk of PAHs in contaminated soil, especially during the first month of treatment.