固定化枝孢霉对铜离子的生物吸附

Biosorption of Cu^(2+) by Immobilized Cladosporium sp.

对固定化枝孢霉(Cladosporiumsp.)吸附Cu2+进行了研究,结果表明,当海藻酸钙浓度为3%,CaCl2浓度为4%,菌量为15%(V:V)时,包埋制得的固定化小球具有较好的机械性能和较高的吸附量。并考察了不同因素如接触反应时间,溶液的pH,温度对生物吸附的影响,结果表明:生物吸附平衡时间为3h左右,固定化空白小球和活菌的最佳pH值分别为3.5和4.0,在15℃～45℃的温度范围内,温度对吸附量变化有一定的影响。在一定浓度范围(30～500mg/L)内,生物吸附随浓度的增加而增加,Langmuir型吸附模式较好描述Cu2+在固定化小球的吸附实验数据,其线性回归系数高达0.99,HCl、HNO3、柠檬酸都是有效的解吸剂,解吸吸附后的海藻酸钙小球,解吸率都在92%以上,其中以硝酸的解吸效果为最好。

The study on adsorption of Cu^(2+) was carried out with immobilized Cladosporium sp.The results showed that, when the concentrations of Na alginate, CaCl_2, and Cladosporium sp. were 3%, 4% and 15% respectively, the immobilized Cladosporium sp. prepared through encapsulating had better mechanical property and was efficient in removing Cu^(2+). The factors affecting the adsorption ability on Cu^(2+), such as the contacting time, initial pH, temperature were investigated . The results showed that biosorption equilibrium was established in about 3 h. The maximum biosorptive capacity of Cu^(2+) on Ca-alginate entrapping spores and no spores was obtained pH 4.0 and 3.5 respectively. Temperature over the range 15℃～45℃ had some significant effort on the biosorptive capacity. The biosorptive capacity increased with initial concentrations in the concentrations range of 30～500mg/L. The adorption of Cu^(2+) on immobilized Cladosporium sp. exhibited Langmuir adorption behavior with regression coefficient of (0.99), Cu^(2+) could be easily desorpted by water solution of HCl, HNO_3 and lemon acid among which HNO_3 was the best eluent up to (92%) recovery. The biosorbents were reused in three biosorption-desorption cycles with negligible decrease in biosorptive capacity.