摘要
研究了菜园土壤镉的吸附 -解吸特性。结果表明 ,等温条件下三种菜园土壤对Cd2 +的吸附量与平衡液中Cd2 +浓度的关系均可用Langmuir方程和Freundlich方程来描述 ,相关系数均达到 0 98以上 ,达极显著水平。由Langmuir方程求得的菜园土壤对Cd2 +的最大吸附量和最大缓冲容量的顺序为 :黄松土 >粉泥土 >江涂砂 ;由Freundlich方程得到的三种菜园土壤对Cd2 +的吸附作用力强度以黄松土为最小 ,粉泥土和江涂砂无明显差别。菜园土壤吸附的Cd2 +的解吸量与吸附量呈极显著正相关 ,但有相当大部分吸附的镉不能被解吸 。
The isothermal sorption and desorption of cadmium in three vegetable garden soils in suburb of Hangzhou city were measured.The isothermal sorption of cadmium fitted well with both Langmuir equation and Freundlich equation.Hence,the parameters in the equations,i.e.,maximum sorption ( x m),constant( k ) and their product ( x m× k )-maximum buffering capacity (MBC) from Langmuir equation and another constant ( α ) from Freundlich equation could be used as comprehensive indexes to characterize the potential Cd sorption of the soils.The maximum sorption and maximum buffering capacity of Cd were both follow the order of Huang Song Tu(Fluavio-marine yellow loamy soil)>Fen Ni Tu (Aquic silt -loamy soil)> Jiang Tu Sha (Fluvio-marine sandy polder soil).The sorption intensity (α)of Cd on Huang Song Tu(Fluvio-marine yellow loamy soil)was the lowest,and that on Fen Ni Tu (Aquic silt -loamy soil) and Jiang Tu Sha (Fluvio-marine sandy polder soil) were similar.The isothermal desorption of Cd was significantly correlated with isothermally absorbed Cd.It is noticeable that part of added Cd was fixed,which represented the Cd fixation capacity of vegetable garden soils.
出处
《广东微量元素科学》
CAS
2000年第10期11-15,共5页
Trace Elements Science
