垃圾渗滤液污染地下环境物质变化对污染缓冲的影响

通过砂柱模拟实验研究垃圾渗滤液污染地下环境中氧化还原环境和主要组成物质的变化对沉积物的pH缓冲能力和氧化还原能力的影响及其相互关系.结果表明,氧化还原环境的变化对地下环境沉积物的pH缓冲和氧化还原缓冲能力有重要影响,产甲烷带/硫酸盐还原带(MGZ/SRZ)、铁还原带(IRZ)、硝酸盐还原带(NRZ)和氧还原带(ORZ)沉积物的pH缓冲容量相对于本底值分别增加了12.4%、 10.8%、 19.8%和11.1%;pH缓冲和氧化还原缓冲之间相互影响、相互促进,它们直接影响着地下环境中污染物的自然衰减作用;沉积物中的铁氧化物、有机质、SO_4~(2-)和NH_4~+-N等的含量对pH缓冲能力和氧化还原缓冲能力均有不同的影响,整个体系的污染缓冲能力是各组分的综合作用结果.

Influences of Matter Variations on Pollution Buffer Capacity of Landfill Leachate Polluted Subsurface Environment

Columns filled with fine sand were constructed to investigate influences of subsurface environment and main constituent variations caused by landfill leachate pollution on pH buffer capacity and redox buffer capacity of sediments. Experimental results indicated that the subsurface environment had significant impacts on pH and redox buffer capacity. The pH buffer capacity increased 12.4%, 10.8%, 19.8% and 11.1% in MGZ/SRZ, IRZ, NRZ and ORZ compared with background value, respectively. pH buffer and redox buffer were interaction and inter-promotion, which influenced natural attenuation processes of pollutants in subsurface directly. Content of iron oxides, organic substrate, SO^2-₄ and NH⁺₄-N in sediments had different impacts on pH buffer and redox buffer capacity, and the overall pollution buffer capacity of system was comprehensive results of constituents.