解脂假丝酵母(Candida lipolytica)对铜的吸附

Bioadsorption of Copper Ion by Candida lipolytica

研究了解脂假丝酵母的表面特性及培养时间、pH值、铜浓度、菌体投加量、吸附时间等因素对铜吸附的影响,并探讨了吸附动力学特征。结果表明,菌体表面可能有-OH和-PO43-,培养96 h的菌体吸附性能最佳,适宜pH为4.0-6.0,适宜菌体投加量为25.0 g·L-1(湿重)。在初始浓度为20 mg·L-1的铜溶液中投加25.0 g·L-1(湿重)的菌体,吸附2 h,铜的去除率最高达86.5％。铜浓度为5,10 mg·L-1时,铜的去除率高达95％以上。动力学分析表明,在实验设定的浓度范围内解脂假丝酵母对铜的吸附基本符合Freundlich吸附模型。红外光谱分析表明吸附后-OH吸收峰蓝移18 cm-1,其它吸收峰没有明显的变化。

The factors which influence the absorption of copper by Candida lipolytica were investigated, including the characteristics of the strain and culture time, pH of water, copper concentration, the strain dosage and the adsorption time. The adsorption kinetics was also detected. The titration of biomass indicated that-OH and-PO43-might exist on the surface of the biomass. The optimum culture time, pH and dosage were 96 h, 4.0-6.0 and 25.0 g·L-1(wet weight), respectively. After 2 hours of adsorption more than 86.5% copper was removed by Candida lipolytica when copper concentration was 20 mg·L-1 and the dosage of strain was 25.0 g·L-1 (wet weight). When the copper concentrations were 5 mg·L-1 and 10 mg·L-1, the removal efficiency of copper reached up to 95%. The kinetics analysis of copper onto the Candida lipolytica revealed that the bioadsorption process of copper in determinated concentrations was in accordance with Freundlich isotherm. The analysis of IR spectrogram indicated that the apex of-OH shifted for 18 cm-1 to long wavenumber, the other apices did not change a lot.