六氯苯污染土壤的固化稳定化  

Solidification/stabilization of hexachlorobenzene polluted soils

作　　者：聂小琴[1] 刘建国[1] 曾宪委[1] 苏肇基[1] 

机构地区：[1]清华大学环境学院,固体废物研究所,北京100084

出　　处：《清华大学学报（自然科学版）》2013年第1期84-89,共6页Journal of Tsinghua University(Science and Technology)

基　　金：国家“八六三”高技术项目(2009AA064001)

摘　　要：针对六氯苯污染土壤以及农药、化工等重污染场地毒性有机物的控制与治理,该文通过在去离子水、硫酸/硝酸混合溶液(pH=3.20±0.05)和醋酸缓冲溶液(pH=4.93±0.05)3种浸提剂情景下的静态浸出试验、长期浸出试验和固化体微观形貌观察等,分析评价了含六氯苯污染土壤模拟样品的固化稳定化效果。试验结果表明:添加质量分数30%—50%水泥便可以实现98%—99%的六氯苯固定率;3种情景下模拟样品121d的累积浸出率,除醋酸缓冲溶液下的石英砂样品达1.09%外,其余样品的浸出率均小于1%,进一步说明水泥对污染土壤中六氯苯有很好的固化稳定化效果;长期浸出过程主要经历了快速溶出、缓慢的扩散迁移和相对稳定3阶段,由于六氯苯的相对稳定性和低水溶性,长期浸出试验在20d后基本进入稳定期。The solidification/stabilization of hexachlorobenzene polluted soils in Portland cement was analyzed using simulated specimens for three different disposal scenarios including deionized water, a sulfuric-nitric acid mixture （pH = 3.20 ±0.05） and an acetic acid buffer solution （pH = 4.93 ± 0.05） using leaching tests, long-term leaching tests and microstructure analyses. The results show that different mass percentages of cement gave different solidifications fractions with a cement mass percent of 50% stabilizing more than 99% of the HCB. The 30 - 40% cement can stabilize more than 98% of the HCB. The cumulative leaching ratios for a 121 days cycle were less than 1%, except for the quartz sand specimen in the acetic acid buffer solution which was 1.09%, which further demonstrates the high solidification/stabilization efficiency of Portland cement for HCB. After the three stages of rapid solution, slow diffusion and relative stability in the long-term leaching tests, the cumulative leaching ratio became stable after 20 days due to the low solubility of the hexachlorobenzene.

关 键 词：六氯苯(HCB) 固化稳定化(s s) 毒性浸出 污染土壤 

分 类 号：X705[环境科学与工程—环境工程]