天然水体中优势菌种非活性细胞吸附Pb^(2+)和Cd^(2+)的热力学及动力学研究

Studies on thermodynamics and kinetics of (Pb^(2+)) and (Cd^(2+)) adsorption onto dominant dead bacteria in natural water

研究了长春市伊通河天然水体中优势菌种非活性细胞对Pb2+和Cd2+吸附规律,发现非活性细胞对Pb2+和Cd2+的吸附符合Langmuir和Freundlich热力学方程.非活性细胞吸附Pb2+和Cd2+的动力学过程分为快速阶段和慢速阶段,其中慢速阶段符合二级吸附速率动力学方程.

The adsorption of (Cd^(2+)) and (Pb^(2+)) onto dominant dead bacteria in natural water was studied. The (results) show that when Langmuir and Freundlich isotherm models were tried to represent the equilibrium data of (Cd^(2+)) and (Pb^(2+)) adsorption onto dominant dead bacteria, equilibrium data fitted very well to both the models in the studied concentration range of (Cd^(2+)) and (Pb^(2+)). The kinetic processes of the adsorption included fast phase and slow phase. Pseudo first-order and pseudo second-order kinetic models were also applied to experimental data on the basis of assuming that the external mass transfer limitations in the system can be neglgected and the adsorption is sorption controlled. The slow phase obeyed the second-order rate expression.