为了研究非水溶性醌类介体加速Cr(Ⅵ)生物还原过程的影响因素,采用乙酸纤维素包埋法固定非水溶性醌类介体,探讨其调控Escherichia coli BL21还原Cr(Ⅵ)的过程.结果表明,蒽醌、1-氯蒽醌、2-氯蒽醌、1,5-二氯蒽醌、1,8-二氯蒽醌和1,4,5,8-四氯蒽醌6种非水溶醌的加速顺序为1-氯蒽醌＞1,5-二氯蒽醌＞2-氯蒽醌＞1,8-二-氯蒽醌＞蒽醌＞1,4,5,8-四氯蒽醌;1-氯蒽醌的最佳加速浓度为0.048 mol/L;生物还原的最佳pH值为7.00;最佳初始Cr(Ⅵ)质量浓度为30mg/L;在温度范围为20～60℃时,Cr(Ⅵ)的去除率随温度的上升而增加;在重复利用性实验中,1-氯蒽醌乙酸纤维素小球循环使用6次,Cr(Ⅵ)生物还原速率仍是空白菌液5倍以上.乙酸纤维素固定非水溶性醌可以有效加速Escherichia coli BL21还原Cr(Ⅵ)过程,具有良好的应用价值.%In order to study the influencing factors of non-dissolved redox mediators on Cr (Ⅵ) bioreduction,the accelerating effect of non-dissolved redox mediators immobilized by cellulose acetate (CA) on the reduction of Cr(Ⅵ) by Escherichia coli BL21 is investigated.The results show that the accelerating order is 1-chloroanthraquinone＞ 1,5-dichloroanthraquinone＞2-chloroanthraquinone＞1,8-dichloroanthraquinone＞ anthraquinone＞ 1,4,5,8-tetrachloroanthtaquinone;the optimal concentration of 1-chloroanthraquinone pH and initial Cr(Ⅵ) concentration are 0.048 mol/L,7.00 and 30 mg/L,respectively;the removal rate increases with the increasing temperature when it is in the range of 20～ 60 ℃;after 6 times of recycling experiments,and the Cr(Ⅵ) bioreduction rate with the immobilized 1-chloroanthraquinone maintains above 5 times of margin bacteriurn's.It indicates that non-dissolved redox mediators immobilized by CA can effectively accelerate the reduction rate of Cr(Ⅵ)by Escherichia coli BL21,which has favourable application value.
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