固定化混合菌Z1对制革废水Cr^(3+)和OPnEO的同步去除及其响应面法优化

The removal of Cr^(3+) and OPnEO in the tannery wastewater by immobilized mixed culture z1 and its optimization by response surface method

以微紫青霉菌B5和醋酸钙不动杆H1按照1∶1配置成混合菌Z1,并分别以聚乙二醇、改性秸秆、海藻酸钠对混合菌Z1进行包埋,探究其对Cr^(3+)和OPnEO的同步去除处理情况,结果得到OPnEO的去除率分别为53.42%、46.29%、55.14%;而Cr^(3+)的去除率分别达到58.41%、54.24%、60.95%,确定海藻酸钠为Z1的最佳包埋材料.以Cr^(3+)去除率为响应值,利用Plackett-Burman实验确定Cr^(3+)的初始浓度、pH值、温度为影响混合菌Z1去除Cr^(3+)的3个主要因素;运用最陡爬坡实验设计,结合Box-Behnken实验设计及响应面法分析,确定海藻酸钠固定化混合菌Z1在初始pH 7.64、Cr^(3+)初始浓度856.34 mg·L^(-1)、温度30.39℃、OPnEO初始浓度950 mg·L^(-1)、外加2 m L胰蛋白胨条件下培养7 d,Cr^(3+)的去除率达到77.69%,比单因素实验条件下Cr^(3+)的去除率提高7%.

The culture Z1,which was mixed with Penicillium janthinellum B5 and Acinetobacter calcoaceticus H1 with the proportion of 1 ∶ 1,was imbedded with polyethylene glycols,modified straw and alginate,respectively,for simultanueous removal of Cr^（3＋） and OPnEO. The respective removal rates of OPnEO were 53. 92%,46. 99% and 55. 14%,and the removal rates of Cr^（3＋） were 58. 41%,54. 24% and 60. 95%. Alginate was confirmed as the optimum embedding material. In the Plackett-Burman experiment,the initial Cr^（3＋） concentration,pH,temperature,were ascertained as three influencing factors for Cr^（3＋） removal by the mixed culture Z1. The steepest ascent experimental design,Box-Behnken experimental design and response surface method analysis have confirmed that the removal rate of Cr^（3＋） reached 77. 69% under the optimal condition,which was initial pH 7. 64,initial Cr^（3＋） concentration at 856. 34 mg·L^（-1）,temperature 30. 39 ℃,initial OPnEO concentration at 950 mg·L^（-1）,2 m L tryptone and 7 d of cultivation,the removal rate of Cr^（3＋） significantly increased 7% than those under the experimental conditions of single factor.