酵母融合菌对Cr的吸附性能及机理分析

Biosorption Performance and Mechanism of Cr by Yeast Fusion Strain

研究了酵母融合菌R32对Cr的吸附性能及机理。结果表明,该菌对C（rⅥ）有着很好的吸附效果,最佳吸附条件为pH≤3,投菌量为10 g/L（含水率（78±2）%）,吸附温度30~35℃,C（rⅥ）的初始浓度≤20 mg/L。当C（rⅥ）的初始浓度为10 mg/L时,总铬及C（rⅥ）的去除率达93.7%和96.5%,总铬的残留浓度不超过1 mg/L,C（rⅥ）的残留浓度不超过0.5 mg/L,均达到了《污水综合排放标准》（GB8978-1996）。Cr（Ⅲ）在溶液中的形态及浓度受pH的影响很大,不同pH条件下菌对C（rⅢ）的去除率差异很大。C（rⅢ）和C（rⅥ）共存不会影响菌对C（rⅥ）的还原与去除。菌吸附C（rⅥ）的过程较好地符合Lagergren准二级吸附动力学模型。通过傅里叶红外光谱和SEM扫描观察,参与反应的基团有羟基、氨基、磷酸基团、蛋白类物质等,细胞表面会出现褶皱。

Biosorption and mechanism of Cr by yeast fusion R32 were investigated.Experimental results showed that R32 has a perfect effect on the removal of hexavalent chromium,with the optimum condition as pH less than 3,yeast dosage 10 g/L with water content of（78±2）%,temperature 30~35 ℃ and initial concentration of Cr（Ⅵ） less than 20 mg/L.When initial concentration of Cr（Ⅵ） was 10mg/L,the removal rate of total Cr and Cr（Ⅵ） were 93.7% and 96.5% respectively,and residual concentrations of total Cr and Cr（Ⅵ） were less than 1 mg/L and 0.5 mg/L individually,which met Integrated Wastewater Discharge Standard of GB8978-1996.Configuration and final concentrations of Cr（Ⅲ） in solution varied with pH greatly.Coexistence of Cr（Ⅲ） and Cr（Ⅵ） did not affect the reduction and removal of Cr（Ⅵ）,with adsorption process following Lagergren pseudo second-order kinetic regression models preferably.FTIR and SEM analysis revealed that there were such functional groups as-OH,-NH2,-PO2-and-CONH-involved in biosorption,and clear pleats on cell surface was observed.