固定化枝孢霉吸附Cu^(2+)的研究

BIOSORPTION OF Cu^(2+) BY IMMOBILIZED CLADOSPORIUM SP.

通过比较包埋法和载体结合法对枝孢霉的固定化性能,确定海藻酸钠-明胶包埋法为最佳固定方法,并利用正交试验得到固定化菌体制备的最优操作条件.探讨了不同环境因素如接触反应时间、溶液pH、温度对生物吸附Cu2+的影响.实验结果表明,固定化菌的吸附作用是先快后慢的过程,在3h达到生物吸附平衡,最佳pH为4.5,在15~45℃温度范围内,吸附量随温度升高有略微增加.在30~400mgL-1范围内,吸附量随Cu2+的初始浓度的增加而增加,整个吸附过程较好地符合Langmuir和Freundlich吸附模型,在浓度为0.5molL-1的多种解吸剂中,HCl的解吸效果最好,解吸率达到99.96%.

By comparison of immobilization capabilities between entrapment method and carrier-bound method, the method with gelatin-alginate sodium as entrapment matrix was considered to be optimal. The optimal preparation conditions for strain immobilization were determined by cross-test experiments. The factors affecting biosorption of Cu^2＋ , such as contacting time, initial pH and temperature were investigated. The result indicated that Cu^2＋biosorption by immobilized Cladosporium sp. was a rapid-first-and-slow-then process. The biosorption equilibrium was established after 3 h. The optimal pH was 4.5. The Cu^2＋ sorption increased slightly with the increase of temperature ranging from 15 ℃ to 45 ℃, and it also increased with the increase of Cu^2＋ initial concentration in the range of 30 - 400 mg L^-1. The Cu^2＋ biosorption process could be fitted to Langmuir and Freundlich models of adsorption isotherm. The desorption of Cu^2＋ from immobilized Cladosporium sp. was also investigated. Among several eluants,0.5 mol L^-1 HCl was the best with a desorption rate up to 99.96%. Fig 3, Tab 5, Ref 12