摘要
从pH的影响、等温吸附、吸附动力学和热动力学4个方面研究了向日葵根分泌物对黄壤吸附Cd2+的行为的影响。随着pH的升高,黄壤对Cd2+的吸附量都升高,而且在pH为3~8的范围内,根分泌物的存在都减少了黄壤对Cd2+的吸附。不论有否根分泌物存在,Langmuir方程和Freundlich方程能满意地描述黄壤对Cd2+的等温吸附行为,黄壤对镉的吸附动力学符合拟二级速率方程,是一个墒减的放热的自发反应。向日葵根分泌物的存在抑制了黄壤对镉的吸附容量和吸附速率,并一定程度上降低了吸附过程的自发性。图4,表3,参11。
The effects of mot exudates from Helianthus annus on Cd^2＋ adsorption to yellow earth were investigated in the present study. It was found that root exudates generally inhibited adsorption of Cd^2＋ onto yellow earth. Cd^2＋ adsorption capacity increased on increasing of solution pH and the presence of mot exudates reduced Coe ＋ adsorption capacity at pH 3 - 8. Cd^2 ＋ isothermal adsorption could be well represented with beth Langmuir and Freundlich equations, and the adsorption kinetics with pseudo-second order equation. Cd^2＋ adsorption capacity to yellow earth is a spontaneous exotheimic reaction. The presence of root exudates reduced the adsorption capacity and adsorption rate.
出处
《农业系统科学与综合研究》
CSCD
2009年第4期406-409,422,共5页
System Sciemces and Comprehensive Studies In Agriculture
基金
中国科学院"百人计划"项目
中国科学院知识创新工程重要方向性项目(KZCX2-YW-335)
国家自然科学基金项目(40673070)
关键词
根分泌物
镉
黄壤
吸附
mot exudates
Cadmium
yellow earth
adsorption.
