The Research Of Coking Wastewater In-depth Processing Enhaced By The Redox Mediator

Coking wastewater contains high concentrations of organic pollutants including some toxic and harmful organic substances.The degradation of these substances were difficult.Redox mediators(ROMs)can changed surface potential through the mutual conversion between reduction state and oxidation state,and then accelerate the electron transfer rate in the reaction or changed the electron transfer mode in the biochemical reaction,thereby promoting biochemical reaction.This study investigated the effects of ROMs on the anaerobic biological treatment of coking wastewater and explored the influence of different ecological factors on the advanced treatment of coking wastewater by ROMs enhancement for improving the biological treatment effect of coking wastewater and realizing the advanced treatment of coking wastewater.Five redox mediators(anthraquinone-2-disulfonic acid(AQS),anthraquinone-2,6-disulfonic acid(AQDS),menadione,hennaquinone and graphene oxide(GO))were selected to investigate the biological treatment of coking wastewater.The results showed that menadione,AQS,AQDS and GO increased the COD removal during the anaerobic biological treatment of coking wastewater.Among them,AQS has the best enhancement effect and the removal is higher than that in control by 13.8%.The anaerobic degradation of TN and turbidity were significantly increased by menadione.The TN removal and turbidity were 49.8% and 69.8%,respectively,which were significantly higher than the control system.The chroma removal could be significantly improved by GO.The results of the anaerobic biological treatment of coking wastewater by enhancement using different concentrations of AQS showed that the AQS concentration of 0.01mmol/L had the most significant effect on the COD removal of38.6%.When the AQS concentration was 0.5mmol/L,the anaerobic degradation of TN was improved and the TN removal reaches 50.23%,which was higher than control by 5.37%.In activated sludge,Proteobacteria,Bacteroidetes and Firmicutes were the dominant phyla,Acinetobacter,Comamonas,Thauera and Pseudomonas are the main genera.The effects of pH and reduced iron powder on the advanced treatment of coking wastewater mediated by AQS showed that the COD removal of the coking wastewater was the highest at p H 7.0,reaching 39.4%.At p H 7.5,the TN removal was the highest.When the dose of reduced iron powder was 1-6g,the COD removal was significantly increased.The degradation of the color and turbidity of the coking wastewater by reduced iron powder of 6g.Acinetobacter,Comamonas,Thaurea and Pseudomonas in activated sludge are the dominant bacterial genera in the iron powder reaction system.