The Efficacy Of Purification Of TP And COD_Cr In Secondary Biochemical Effluent By Iron-carbon Microelectrolysis

With the improvement of the emission standards for urban sewage treatment plants in China,it is necessary to take further advanced treatment of secondary biochemical effluent to ensure that the effluent quality of the urban sewage treatment plants can meet the requirements of the Class A emission standards of the Pollutant Discharge Standards for Urban Sewage Treatment Plants?GB3838-2002?.Taking the secondary biochemical effluent from a domestic sewage treatment plant as the research object,this study adopted iron-carbon microelectrolysis technology to discuss the influence factors and efficiency of the removal of TP and COD_Crr in the secondary biochemical effluent.This program also further discussed the feasibility of the iron-carbon micro-electrolysis system for the degradation of bisphenol A and dichlorvos in wastewater.The main conclusions from this study are as follows:The optimally experiment parameters are determined by the single factor impact analysis,which contain the initial pH of the suitable wastewater of the iron-carbon microelectrolysis system with 3,the iron-carbon mass ratio with 1:1.5,and the stirring strength with 120r/min.Orthogonal experiments are designed based on above optimal parameters,which show that the affecting magnitudes of the removal of TP and COD_Crr in wastewater are the initial pH value>iron-carbon mass ratio>stirring intensity>reaction time.The best combination of various influencing factors is the initial pH value with 3.0,the iron-carbon mass ratiowith1:1.5,the reaction time with 60 min,and the stirring strength with 120 r/min.Under these conditions,the removal rates of TP and COD_Crr in wastewater by the monolithic iron-carbon microelectrolysis system consisting of iron and saturated carbon were 20.91%and20.79%;The residual concentration of TP and COD_Crr were 0.46mg/L and 43.54mg/L,respectively.The removal rates of TP and COD_Crr in wastewater by the fragmented iron-carbon microelectrolysis system combining with iron and saturated carbon were 25.15%and 30.21%;The residual concentration of TP and COD_Crr were 0.43mg/L and38.37mg/L,respectively.Under the same conditions,the removal efficiency of TP and COD_Crr in wastewater by iron and unsaturated carbon through the iron-carbon microelectrolysis system is better than that iron and unsaturated carbon.Furthermore,the removal efficiency of TP and COD_Crr in wastewater through the fragmented iron-carbon microelectrolysis system is better than that saturated iron-carbon.The iron-carbon microelectrolysis system has a certain removal effect on the TP and COD_Crr in the secondary biochemical effluent,but the removal efficiency was less than 50%.In a summary,the iron-carbon micro-electrolysis system has a certain degradation effect on bisphenol A and dichlorvos in wastewater,and the iron-carbon micro-electrolysis system should be used for the treatment of refractory Organic matter in secondary biochemical effluent.For the secondary biochemical effluent of a municipal sewage treatment plant taken in this research,the iron-carbon micro-electrolysis technology can make the TP and COD_Crr indicators of the urban sewage treatment plant to meet the“Emission Standard of Pollutants in Urban Sewage Treatment Plants”?GB18918-2002?Level A standard requirement.