红螺菌吸附铜的动力学与脱附研究

Study of kinetics and desorption of copper biosorption by Rhodospirillum

研究了红螺菌(Rhodospirillum)对Cu^(2+)的吸附动力学行为,在一定的条件下,吸附在45 min达到平衡,吸附平衡时最大吸附量为48.23 mg·g^(-1)。应用准一级和准二级反应动力学模型进行数据分析,结果表明菌体对Cu^(2+)的吸附符合准二级动力学模型。比较分析了多种脱附剂对菌体脱附,EDTA和柠檬酸是较有效的洗脱剂,脱附率分别为86.4％、66.9％;无机酸及无机盐对菌体的脱附效果很差,脱附率在20％左右。X-射线衍射分析表明,菌体吸附Cu^(2+)后没有形成新晶相,并且菌体部分晶相转变为非晶相。

The kinetics analysis of copper onto the Rhodospirillum was investigated. Under the experimental conditions, the biosorption equilibrium was achieved within 45min, the most biosorption capacity could reach 48.23 mg·g^(-1). In order to analyze the biosorption kinetics of Cu^(2+), the pseudo-first-order and the pseudo-second-order kinetic models were applied to the data. The results showed that the pseudo-second-order kinetic model fitted well with the experimental dam. It was found that EDTA and citric acid were the effective eluants for the elution of adsorbed copper by Rhodospirillum,the elution efficiency were 86.4%, 66.9%, respectively. The abio-acid and the abio-salt were the noneffecive eluants,the elution efficiences were all about 20%. The analysis of the X-ray diffraction spectra indicated that the bacteria did not form new crystal after the adsorption and some of the crystal of the bacteria had transformed into non- crystal.