自然水体生物膜吸附Co,Ni和Cu的特征研究

Studies on the Characteristics of Co, Ni and Cu Adsorption to Natural Surface Coatings

研究了在自然水体中培养的生物膜吸附 Co,Ni和 Cu等 3种重金属的热力学和动力学特征 ,并对生物膜吸附各重金属的热力学数据进行了非线性拟合 .结果表明 ,3种重金属的吸附过程均符合 Langmuir吸附等温曲线 .在溶液中重金属浓度 <0 .5μmol/L时 ,生物膜对 3种重金属元素的吸附能力顺序是 Co>Cu>Ni;在重金属浓度 >0 .5 μmol/L时 ,顺序是 Cu>Co>Ni.对动力学数据进行非线性拟合的结果表明 ,生物膜对 Co,Ni和 Cu的吸附均在数小时内达到平衡 ,吸附过程符合

Surface coatings developed in the Nanhu Lake(Changchun) were used to study the characteristics of thermodynamics and kinetics of Co, Ni, and Cu adsorption to them. Statistical analysis of the adsorption data show that the thermodynamic data of each metal fit the Langmuir isotherms. At low ion concentrations(<0 5 μmol/L), the adsorption capacity of these metals to the surface coatings decreased in the order Co, Cu, and Ni, while at high ion concentrations(>0 5 μmol/L), the capacity decreased in the order Cu, Co, and Ni. The kinetic data indicate that the adsorption reached equilibrium in several hours. Four kinetic models, i.e., Elovich equation, double-constant rate equation, first-order kinetics equation and Langmuir kinetics equation, can all be used to describe the adsorption process, especially the Langmuir kinetics equation.