[Catalyst effect and the structure-activity characteristics of redox mediators on the reactive brilliant red K-2BP decolorization].

Four selected quinone redox mediators with similar structure were conducted to accelerate reactive brilliant red K-2BP decolorization, and the accelerating structure-activity of redox mediators on the decolorization was also studied. Batch experiments were carried out to determine the catalyst effect on the decolorization of reactive brilliant red K-2BP with temperature of 35 degrees C and under anaerobic conditions. The experiment results suggested that (1) four similar chemical structure redox mediators [1, 4, 5, 8-Tetrachloroanthraquinone (1,4,5,8-AQ), Anthraquinone (AQ), 1,8-Dichloroanthraquinone (1,8-AQ), 1,5-Dichloroanthraquinone (1,5-AQ)], all accelerated the decolorization rate of reactive brilliant red K-2BP and the reaction rate was enhanced 1.4-3 times; (2) the accelerating order was 1,8-AQ >1 ,5-AQ > AQ >1,4,5,8-AQ at the quinone mediator concentration of 4 mmol x L(-1) and reactive brilliant red K-2BP concentration of 300 mg x L(-1); (3) under the reactive brilliant red K-2BP concentration of 300 mg x L(-1), 1,8-AQ had best accelerating effect, and the relationship between decoloring rate constants and 1,8-AQ concentration; (4) and the mediator acclerating effects also related to substituent positioning effects and conjugated effects. The structure-activity mathematical model of redox mediators was put forward, which could improve water-insoluble redox mediators catalytic strengthening theory system.