渗滤液污染地下氧化还原环境与污染物衰减研究

Redox environment and attenuation of pollutants in leachate contaminated aquifer

通过土柱实验研究垃圾渗滤液污染地下氧化还原环境的分带现象与污染物的衰减规律。实验结果表明:垃圾渗滤液污染晕中出现了3个顺序氧化还原带,依次为铁还原带、硝酸盐还原带和氧还原带,各带标志性物质Fe3+、NO2-和O2的最高质量浓度分别为14.81、1.41、5.8mg/L;COD与NH4+-N在监测区间内呈现出相似的衰减规律,随距离的增加浓度降低,随时间的推移浓度升高,COD初期最高去除率达76.8%,后期降到50.0%;NH4+-N初期最高去除率达98.1%,后期降到90.2%。

The redox environment of landfill leachate contaminated subsurface and degradation of pollutants in a soil column were investigated. Three sequential redox zones were defined based on the concentration profiles of the indicators （the most important species of each zone）. The indicators for the iron reduction zone, nitrate reduction zone and oxygen reduction zone were Fe^3＋ , NO^-2 and dissolved oxygen, respectively; their maximum observed concentrations were 14.81 mg/L, 1.41 mg/L and 5.8 mg/L. The concentration profiles of COD and NH^4＋-N were similar.. both concentrations decreased with distance and increased with time. The COD removal rate was 76.8% initially and declined to 50.0% at the end of the test, while the same for NH^4＋-N were 98. l%and 90.2%.