中文摘要：

通过土柱实验研究垃圾渗滤液污染物在地下环境中降解的生物地球化学作用和分带现象，并对污染前后土壤中的Fe^3＋、Fe^2＋、氧化容量（OXC）和还原容量（RDC）等的变化进行分析．结果表明，垃圾渗滤液污染羽中出现了4个顺序氧化还原带，微生物在每个带所利用的最终电子受体是不同的，分别为CO2、Fe^3＋、NO3^-和O2，相应地依次称为产甲烷带、铁还原带、NO3^-还原带和氧还原带；各带的标志性物质HCO3^-、Fe^2＋、NO2^-和DO的最高值分别为10353mg／L、13．61mg／L、0.097mg／L和5．8mg／L；土壤的OXC依次不断增大，产甲烷带最小为14．18μmol／g，氧还原带最大为24．45μmol／g；RDC则依次不断减小，产甲烷带最大为224．84μmol／g，氧还原带最小为140．22μmol／g，随着污染的不断加剧，土壤矿物中的Fe^3＋在生物地球化学作用下被还原为可溶的Fe^2＋，部分进入水体，另一部分则沉积下来。因此氧化还原带的作用机理研究对垃圾污染场地的原位修复和风险评价具有重要意义。

英文摘要：

A soil column filled with sandy soil was constructed to investigate biogeochemical process of leachate pollutants degradation and redox zones in subsurface environment, and variation of Fe^3＋ , Fe^2＋ , oxidation capacity （OXC） and reduction capacity （RDC） of fresh and contaminated soil were analyzed. Experimental results indicated that four sequent redox zones are appear in pollution plume, and different terminal electron acceptors （they are CO2, Fe^3＋ , NO3^＋ and O2 ） were used by microbes in different zones; Zones can be named methanogenic zone, iron reduction zone, nitrate reduction zone and oxygen reduction zone correspondingly; the indicator of the different zone is HCO3^- , Fe^2＋, NO2^- and DO, and its highest concentration is 10353 mg/L, 13.61 mg/L, 0.097 mg/L and 5.8 mg/L respectively. OXC of the soil is increased sequentially, its lowest value is 14.18 μmol/g in methanogenic zone and highest value is 24.45 μmol/g in oxygen reduction zone; RDC of the soil is reduced sequentially, its highest value is 14.18 μmol/g in methanogenic zone and lowest value is 24.45 μmol/g in oxygen reduction zone . With the more serious contamination, Fe^3＋ minerals of the soil are reduced by biogeochemical process, and dissolved Fe^2＋ is produced. Some of the Fe^2＋ is released to water and the other is precipitated as sediments. Therefore, it is significant for the in situ remediation and risk assessment of the landfill contaminated site to investigate of the redox zones.