A Novel Two-level Dielectric Barrier Discharge Reactor For Dyeing Wastewater Degradation

Water pollution is facing grave challenges in modern society.With rapid development of printing and dyeing industry,chemical industry,large amount of low-degradable organic dyeing wastewater were produced,which caused a serious environmental problems.Therefore,the study of a new,efficient and stable wastewater treatment technology is urgent.In this paper,according to the plasma technology in Advanced Oxidation Process,a novel two-level dielectric barrier discharge(DBD)reactor was designed which could continuously degrade wastewater with high concentration and large processing capacity.The degradation process and degradation mechanism of methyl orange wastewater in the novel two-level(DBD)reactor were investigated by means of ultraviolet spectrum(UV),Infrared spectrum(IR),liquid chromatography–mass spectrometry(LC–MS).The influence factors that affect the degradation of MO dyeing wastewater in the DBD reactor had been also researched.Finally,the novel two-level DBD reactor was used to discharge the actual dyeing wastewater.The novel two-level DBD reactor could continuously degrade various dyeing wastewaters with high concentration and large processing capacity.The degradation rate of chrome black T can reach to 99.8%,the degradation rate of chemical oxygen demand(COD)was about 44%;the methylene blue degradation rate can approach to99%,COD degradation was about 80%;methyl orange degradation rate can reach to94%,COD degradation rate was about 48%.The pH of methyl orange wastewater decreased with the increasing residence time,while electrical conductivity and degradation rate increased with the increasing residence time;COD of methyl orange fluctuated with a decrease-increase-decrease trend,and then leveled off as resistance time extended.In this novel two-level DBD reactor,the degradation process of methyl orange dyeing wastewater can be degraded continuously and efficiently when the discharge voltage was 13.4kV,the current was3 A,the first discharge distance was 10 mm,and the second discharge distance was10 mm.And the appropriate applied voltage was 13.4kV;low initial concentration and low initial pH value were conducive for MO degradation.Analysis indicated that the degradation products of methyl orange after 130 min may be NO3-?HOOC(CH2)5SO3-.What's more,the degradation mechanism of methyl orange was introduced.Decomposition of methyl orange molecules has experienced two stages: the broken key oxidation and oxidation of benzene ring,producing CO2?H2O and some organic carboxylic acid.Finally,the methyl orange wastewater was effectively degraded in the DBD reactor.