Cd^(2+)、Pb^(2+)在湘江流域河床表层沉积物上的吸附特性研究  

ADSORPTION CHARACTERS OF Cd^(2+),Pb^(2+) ON SURFACE SEDIMENTS FROM XIANGJIANG RIVERBED

作　　者：吴慧英[1] 张颖[1] 童笔峰 杨日剑 

机构地区：[1]湖南大学土木工程学院,长沙410082

出　　处：《环境工程》2016年第6期1-5,共5页Environmental Engineering

基　　金：湖南省建设厅科技项目(湘财建指[2015]105号)

摘　　要：以湘江流域河床表层沉积物为吸附剂,用于去除水中Cd^(2+)、Pb^(2+),系统研究了沉积物对Cd^(2+)、Pb^(2+)的吸附规律,并探讨了其吸附Cd^(2+)、Pb^(2+)后的化学稳定性。结果表明,当2种离子单独存在时,沉积物对Cd^(2+)、Pb^(2+)均具有较好的吸附效果;当2种离子同时存在时,由于竞争作用,沉积物对Cd^(2+)和Pb^(2+)的吸附量分别减小了约40%和16%。对吸附平衡的溶液进行曝气和用双蒸水清洗吸附饱和的沉积物后,Cd^(2+)、Pb^(2+)的释放比例较小,说明湘江流域河床表层沉积物吸附Cd^(2+)、Pb^(2+)后,其化学稳定性较好。沉积物的SEM、FTIR和XRD分析发现,沉积物结构多孔,表面含有大量—OH、—NH,这些基团在吸附重金属阳离子过程中起重要作用。研究结果表明,湘江流域河床表层沉积物对去除水中的Cd^(2+)、Pb^(2+)有较好的效果,该成果对湘江流域重金属污染控制具有重要参考价值。Surface sediments from the Xiangjiang Riverbed were applied as an adsorbent for removing Cd^2＋and Pb^2＋in aqueous solution. Systematic study was carried out on the adsorption of Cd^2＋and Pb^2＋and the chemical stability of surface sediments after the adsorption of Cd^2＋and Pb^2＋. The results indicated that the surface sediments exhibited good adsorption performance for Cd^2＋and Pb^2＋ions in the single metal adsorption system. Because of the competition between Cd^2＋and Pb^2＋,the adsorption capacity of Cd^2＋and Pb^2＋decreased by about 40% and 16%, respectively, under the same experimental condition in the binary system. Aeration was carried out in the adsorption equilibrium solution and the exhausted adsorbent was washed by distilled water. It turned out that only a little desorption of Cd^2＋and Pb^2＋occurred,which illustrated that the surface sediments had a good chemical stability after adsorption of Cd^2＋and Pb^2＋. SEM,FTIR and XRD analysis indicated that the surface sediments was porous and contained a large number of —OH and —NH groups,which played an important role in the adsorption of heavy metal cations. This study suggested that the surface sediments from Xiangjiang Riverbed showed a good adsorption for Cd^2＋and Pb^2＋in aqueous solution,and the result obtained from the study provided an important reference value for the control of heavy metal pollution in Xiangjiang River.

关 键 词：湘江表层沉积物 CD^2+ PB^2+ 吸附 竞争吸附 表面形态结构 

分 类 号：X52[环境科学与工程—环境工程]