Persulfate Non-radical Activation By Activated Carbon For Removal Of Chlorinated Organic Contaminants In Water

The removal of refractory organic pollutants is a hotspot and a difficult point in the field of pollution control.Persulfate(PS)activation for degradation of refractory organic pollutants has strong oxidability and applicability in wide pH range,which is the hot topic in the field of advanced oxidation processes.Persulfate non-radical activation has the property of selectively removing chlorinated aromatic hydrocarbons,the catalyst is the key of it.Activated carbon(AC)is a cheap,stable and environmental-friendly carbon material,which was used to activate PS in this study.An economical and efficient method of activating PS was developed for the treatment of chlorine-containing organic pollutants in water.The effects of AC dosage,PS concentration,solution pH and other factors on the removal of p-chloroaniline(PCA)was systematically investigated,the intermediate products and the pathway of PCA degradation were studied.Results demonstrated that 80% chlorine in PCA was decreased in 2 h and 41% TOC was removed in the PS/AC system;PCA removal was significantly influenced by water quality,oil and surfactant can lead the inhibition of PCA removal in the PS/AC system.PS activation in the PS/AC system was a non-radical process.Reactive oxidative species in PS/AC system were investigated,the major reactive oxidative species was activated PS,the singlet oxygen removed about 20% PCA.The selective removal of pollutants was conducted.The selective removal of chlorinated aromatic hydrocarbons in PS/AC system was showed,pH had significant influence on removal of 2,4,6-Trichlorophenol(TCP),2,4-dichlorophenol(DCP)and 4-chlorophenol(CP).The efficiency of pollutants removal: CP<DCP?TCP(acidic condition),TCP<DCP?CP(neutral condition)and DCP<TPC<CP(alkaline condition).Chlorine ions could be oxidized and added to the organic matter in PS/AC system,which lowered the dechlorination efficiency of pollutants in PS/AC system.Removal of PCA and CP in PS/AC system was compared,the pollutant with strong electron-donating group was removed easily.