【摘要】 为研究硫酸盐还原条件下多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)类有机污染物在土壤中的污染分布规律和迁移转化过程,设计了室内土柱淋溶试验,选择菲、蒽和芘作为PAHs的代表,模拟硫酸盐还原条件下PAHs在土壤中的迁移转化过程.监测土壤中PAHs的垂直分布、淋出液中ρ(PAHs)和ρ(SO42-)、淋出液的氧化还原电位(Eh)和总体积,并通过质量平衡计算出PAHs的降解率.结果表明:①菲和蒽的相对淋出率总体都不超过2%.120 d后菲和蒽在土壤中的残留率分别为51.87%和51.21%,而芘有90%以上吸附在土壤中,在淋出液中未检出.②随着淋溶时间的延长,土壤中的氧气逐渐被消耗,淋出液中ρ(SO42-)和Eh逐渐降低,并趋于稳定,硫酸盐还原作用发生.③3种PAHs在硫酸盐还原条件下都存在一定程度的降解.菲和蒽的降解率相差不大且随淋溶时间的延长逐渐增大,120 d后菲和蒽的降解率分别为47.41%和48.10%,而4环的芘降解速率非常低,120 d后降解率仅为3.61%.更多还原

【Abstract】 The distribution and transportation of polycyclic aromatic hydrocarbon（PAH） contamination in soil under sulfate-reducing conditions were studied through column experimentation.Phenanthrene,anthracene and pyrene were selected as representative PAHs,and their vertical distributions in the soil column,their mass concentrations,and sulfate radical ion and E_h values in leaching solution were detected under simulated sulfate-reducing conditions.Also,the mass balance of PAHs was analyzed to calculate the biodegradation rate of PAHs.The result showed that the leaching ratios of phenanthrene and anthracene were not more than 2%,and their residual ratios after 120 days were 51.87% and 51.21%,respectively.However,more than 90% of pyrene was absorbed in the soil and not detected in the leaching solution.The concentrations of sulfate radical ion and E_h of the leaching solution decreased with leaching time;this was attributed to O₂ depletion.Phenanthrene,anthracene and pyrene degraded under sulfate-reducing conditions,and,after 120 days,their biodegradation ratios were 47.41%,48.10% and 3.61%,respectively.Pyrene degradation was slowest.The experiment result indicated that phenanthrene,anthracene and pyrene could be degraded by acclimated native microorganisms in soil under sulfate-reducing conditions,which provided a theoretical basis for in-situ remediation of PAHs pollution in soil.更多还原