pH值和流速对向海盐碱湿地土壤草根层吸附铅、镉规律的影响  

Effects of pH and flow rate on the adsorption processes of Pb and Cd onto the soils sampled from the sod layers in Xianghai Wetland

作　　者：李鱼[1] 张华鹏[1] 王晓丽[1] 李青山[2] 王月[1] 路永正[1] 

机构地区：[1]吉林大学环境与资源学院环境科学系,长春130023 [2]松辽流域水资源保护局,长春130021

出　　处：《吉林大学学报（理学版）》2004年第4期628-632,共5页Journal of Jilin University:Science Edition

基　　金：国家自然科学重点项目基金(批准号:50139020).

摘　　要：利用柱实验,考察了向海盐碱湿地土壤草根层吸附Pb2+和Cd2+过程中的影响因素.结果表明,流速和pH值对动态吸附有很大影响,流速加快,穿透点提前,穿透点吸附量减小;pH增加,穿透点滞后,穿透点吸附量增大;Pb2+与Cd2+在吸附过程中存在竞争吸附,Pb2+对Cd2+的吸附影响较大,而Cd2+对Pb2+的吸附影响相对较小.不同pH值下,Pb2+和Cd2+的动态吸附过程均可用双常数速率方程和Elovich方程描述,且双常数速率方程更好.The influences of flow rates and pH value on the adsorption of Pb and Cd by the sod layers from Xianghai Wetland were studied by the means of dynamic adsorption experiments. The results show that the penetrative point was advanced and the adsorbance at penetrative point was decreased with the increasing of the flow rates of the solution or the decreasing of pH value of the solution. When (Pb^(2+)) and (Cd^(2+)) coexisted with the initial equivalent concentration, their retention by soil was reduced compared to those when they existed individually, and the reduced percentage of (Cd^(2+)) was greater than that of (Pb^(2+)). The dynamic adsorption procedures of (Pb^(2+)) and (Cd^(2+)) on the soils can be described via double-constant rate (equation) and Elovich (equation) and described better by the former.

关 键 词：CD^2+ PB^2+ 吸附量 湿地土壤 PH值 吸附过程 流速 穿透 常数 动态吸附 

分 类 号：X703[环境科学与工程—环境工程] X172