酵母菌Y17吸附Cu2+的影响因素及吸附机理研究

以高效吸附Cu2+的酵母菌Y17为材料, 对其吸附Cu2+过程中的主要影响因素, 包括溶液pH、Cu2+初始浓度、菌体添加量、吸附时间和温度以及吸附机理进行了探讨。结果表明, 对吸附过程影响较大的因素依次为吸附液pH值、Cu2+初始浓度、菌体添加量和吸附时间。正交试验得到最佳吸附条件为溶液pH5.0, 吸附时间40 min, 加菌量5.0 g湿菌/L时, 对初始浓度为8 mmol/L的Cu2+达到最佳吸附率为82.7%。通过对Y17菌体不同处理及解吸实验, 初步确定Y17吸附Cu2+的位点在细胞壁, 细胞壁表面的-NH2, -COOH基团在其吸附过程中起着重要作用。

Influence Factors and Absorbing Mechanics of Copper Ion by Yeast Strain Y17

Using the high efficient copper-adsorbing yeast strain Y17 as absorbing material, the major affect factors including pH, original concentration of Cu2+, cell biomass, adsorption time and temperature were examined, and then the absorbing sites of the Y17 was determined. The results showed that the solution pH was the most dominate factor which affected the biosorption of Cu2+, the other affecting factors were the initial concentration of Cu2+, the cell biomass added, and adsorption time, respectively; the temperature had little effect on the rate of biosorption. The orthogonal experiment showed that the optimal absorption condition was as follow: the solution pH was 5.0, the absorption time was 40 min, the cell biomass of Y17 added was 5.0 g/L, and the concentration of Cu2+ was 8 mmol/L; the highest adsorbing rate was up to 82.7% at this condition. Based on the results of different pretreatments and the desorption of Cu2+, the cell wall of Y17 was identified as the main place occurring boisorption process, and the -NH2 group, -COOH group on the surface of the yeast cells played an important role on the boisorption process.