含水层介质对垃圾渗滤液污染缓冲性研究  

Buffer Capacity of Aquifer Media Polluted by Landfill Leachate

作　　者：董军[1] 赵勇胜[1] 刘莹莹[1] 

机构地区：[1]吉林大学环境与资源学院,长春130026

出　　处：《环境科学》2009年第2期484-487,共4页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2004CB418505);国家自然科学基金项目(40802055)

摘　　要：通过土柱模拟实验研究含水层介质对垃圾渗滤液污染的pH缓冲和氧化还原缓冲性能.结果表明,碳酸钙对pH缓冲起重要作用,随着污染程度的加重,碳酸钙缓冲体系的缓冲容量逐渐增大,从背景值的1.62.pH-1mmol/kg增加到41.3.pH-1mmol/kg.随着污染程度的加重,含水层介质的氧化容量(OXC)减小,而还原容量(RDC)升高.在未受污染的介质中,Fe3+是OXC的主要组成,约占OXC的70.5%;TOC是RDC的主要组成,约占RDC的98.7%.物质的存在形态也与污染程度有关,在污染源附近大部分无定型态和部分晶体态Fe3+被还原,而且还原产物主要以FeCO3和FeS形式沉淀;生成Fe2+的沉积使得可离子交换态Fe2+含量由未受污染的介质中的0.5%升高至3%.因此,Fe3+是含水层介质中主要的氧化还原缓冲剂.A column filled with fine sand was constructed to investigate pH buffering capacity and redox buffering capacity of aquifer media. Experimental results indicated that calcium carbonate played a significant role in pH buffering; with the aggravating of landfill leachate pollution, the pH buffering capacity of calcium carbonate was increased; it increased from background value, which was 1.62·pH^-1 mmol/kg, to 41.3·pH^-1 mmol/kg. With the aggravating of landfill leachate pollution, the oxidation capacity （OXC） of aquifer media was decreased, and the reduction capacity （RDC） was increased. In unpolluted aquifer media, Fe^3＋ was the main component of OXC, and accounted for about 70.5 % of OXC ; TOC was the main component of RDC, and accounted for about 98.7 % of RDC. Species of the minerals was related to the degree of pollution; large fraction of amorphous Fe^3＋ and part of crystalline Fe^3＋ were reduced near the pollution source, and the reduced product was mainly precipitated as FeCO3 and FeS. Deposit of produced Fe2. led to ion-exchangeable Fe^2＋ content increased from 0.5% of uncontaminated aquifer media to 3 %. Therefore, Fe^3＋ may act as a very significant redox buffer in aquifer.

关 键 词：含水层 垃圾渗滤液 氧化还原缓冲 pH缓冲 

分 类 号：X523[环境科学与工程—环境工程]