岩溶区棕色石灰土胶体对镉铅的等温吸附特性研究  

Isothermal adsorption of cadmium and lead by brown calcareous soil colloids in a Karst Area

作　　者：张蓉蓉 蒋代华[1] 史鼎鼎 王世佳 ZHANG Rong-rong;JIANG Dai-hua;SHI Ding-ding;WANG Shi-jia(College of Agriculture,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学农学院

出　　处：《农业环境科学学报》2020年第3期554-562,共9页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41661076)~~

摘　　要：为了解岩溶地区石灰性土壤胶体对重金属Cd、Pb离子的吸附特性,本研究选取广西岩溶区具有代表性的棕色石灰土来提取土壤胶体,模拟实际土壤污染情况,开展土壤胶体对Cd、Pb的吸附试验,并研究了Cd、Pb离子间的竞争关系及有机质在吸附试验中的作用效果。结果表明:胶体对两种重金属离子的等温吸附用Langmuir、Freundlich和D-R模型均能拟合,拟合优度均在0.93以上;单一溶液中Cd、Pb的平均分配系数与混合溶液相比有所提高,分别升高0.81和0.30,去除有机质后的胶体对Cd吸附量降低了30%~46%,对Pb吸附量下降了14%~25%。与Cd2+相比,Pb2+与胶体亲和力更大更易牢固地吸附在胶体上;混合溶液中两种离子间存在竞争干扰作用,其中Cd2+更易受到Pb2+的影响;去除有机质会减少胶体吸附位点使吸附量下降。We aimed to understand the adsorption characteristics of brown calcareous soil colloids on cadmium and lead ions in Karst Area.The brown calcareous soil in a Karst Area in Guangxi was sampled to extract soil colloids,which were used to evaluate the adsorption char⁃acteristics of cadmium and lead.The results revealed the following.In the Langmuir,Freundlich,and D-R isothermal models for the two heavy metal ions,the isothermal adsorption curve fit results were above 0.93.Compared with the mixed solution,the distribution coefficient in the single solution of lead and cadmium was increased by 0.81 and 0.30,respectively.After removing the organic matter,the adsorption capacity of cadmium by colloids decreased by 30%~46%and that of lead by 14%~25%.The affinity of colloids for lead was greater than that for cadmium.Cadmium was easily affected by lead in a mixed solution of metal ions.The removal of organic matter decreased the ad⁃sorption capacity of colloids.

关 键 词：岩溶区 胶体 镉 铅 等温吸附 

分 类 号：S153.3[农业科学—土壤学]