Study On Treatment Of Coking Wastewater By Electrochemical Coupled-iron Ion Activating Persulfate

Coking wastewater contains a large number of refractory aromatic compounds and polymer compounds,it is harmful to the environment and human health,which has aroused people's wide concern.Coking wastewater is well known for its toxicity and refractory,so it has great challenges to the treatment of coking wastewater.Advanced oxidation process?AOP_S?is the main development trend of coking wastewater treatment at present.AOP_S can generate strong radical oxidants.The strong radical oxidants react non-selectively with most organic substances and can degrade complex compounds.In this study,selecting different ferrous ion and electrochemical coupling to excite persulfate deal with coking wastewater for further treatment.using iron plate?IP?and vanadium titanium magnetite?VTM?as carriers of ferrous ions.The appearance structure of ferrous ion carrier was analyzed by SEM-EDS,XRD and XPS.At the same time,the trends of COD,UV₂₅₄54 and TOC of coking wastewater after treatment were analyzed.FTIR,GC-MS and 3D-EEM were combined to analyze the types of organic matter in before and after treatment of coking wastewater.The results show that:In the iron plate?IP?coupled electrochemical oxidation?EO?activated persulfate?KPS?system?EO/IP/KPS?oxidation treatment coking wastewater,the electrolysis time is 30min and the current density is 15mA/cm^2,The dosage of KPS is 2mmol/L,The concentration of COD and TOC decreased from 175.13mg/L and 125.61mg/L to 40.25mg/L and 55.88mg/L respectively,and the UV₂₅₄54 value changed from 2.28 to 0.334.Secondly,by means of characterization?SEM-EDS,XRD and XPS?,it was proved that the iron floc produced in the electrolytic process contains iron oxides and iron hydrides.Vanadium titanium magnetite?VTM?coupled electrochemical oxidation?EO?activated potassium persulfate?KPS?system?EO/VTM/KPS?oxidation treatment of coking wastewater The dosage of VTM is 4g,the current density is 15mA/cm²,the dosage of KPS is 4mmol/L,The concentration of COD and TOC decreased from 180.15mg/L and 130.84mg/L to 10.31mg/L and54.95mg/L respectively,and the UV₂₅₄54 value changed from 2.31 to 0.323.The structure of VTM was basically unchanged before and after the reaction.And mainly iron oxide compounds.The main aromatic compounds,phenols and carboxylic acids in raw coking wastewater were obtained by FTIR,GC-MS and 3D-EEM.The wastewater treated by the EO/IP/KPS and EO/VTM/KPS systems was small molecule compounds,aromatic structures and macromolecular structures can be decomposed into aliphatic structures and small molecule compounds.