高含沙水体中黄土吸持和释放铜的机理  

Copper Sorption and Desorption by Loess in Water-Sediment Systems

作　　者：张岚[1] 倪晋仁[1] 孙卫玲[1] 赵蓉[1] 

机构地区：[1]北京大学环境工程系水沙科学教育部重点实验室,北京100871

出　　处：《环境科学》2003年第3期79-84,共6页Environmental Science

基　　金：国家重点基础研究发展规划资助项目(G19990 43 60 3 )

摘　　要：研究了高含沙体系中不同环境因素条件下黄土中铜的吸持和释放机理 .实验结果表明 ,黄土对铜的专性吸附和对铜的碳酸盐、氢氧化物等的沉淀作用很强 ,使黄土对铜有很强的吸持能力 .黄土中铜的吸持量随着水体离子强度的增加而减小 ,且支持电解质阳离子电荷数不同对铜吸持的影响也不同 .黄土中吸持的铜在中性盐溶液中释放率小于 4 % ,且随溶液离子强度的增加而增加 .pH是影响铜释放的最重要因素 ,酸性溶液中铜的释放量大于70 % ,铜释放量随释放溶液 pH的降低而增加 .水土体系 pH恒定时 ,铜吸持量相同的等量黄土 ,释放溶液体积越多 ,铜的释放量和释放率越高 ;相同含沙量条件下 ,吸持量越大 。A series of experiments were designed to investigate copper sorption and desorption by loess in hyper concentrated sediment systems. The results demonstrate that loess had large copper sorption capacity because of its specific adsorption and precipitation of carbonate and hydroxide. Copper sorption decreased with increasing ionic strength of solution, but the effects of varying cationic charge of supporting electrolyte were still detected. Less than 4% of copper was desorbed in the neutral saline solution, and increased with increasing ionic strength of solution. The pH was the most dominant factor on copper desorption. More than 70% of copper can be desorbed in the acid solution, and copper desorption increased with the decrease of solution pH. When pH of solid liquid system was fixed, copper desorption from equivalent loess increased with the increase of solution volume, and copper desorption in the same sediment concentration increased with the adsorptive capacity.

关 键 词：黄土 铜 吸持 释放 离子强度 PH 

分 类 号：X522[环境科学与工程—环境工程]