Effect and mechanism of activated carbon on the generation of disinfection by-products during chlorination process of dissolved organic matter
Activated carbon(AC)and chlorine are both widely used agents in the water treatment process,and their contact is inevitable during the actual use.Therefore,it is important to study the effects of AC on the generation of disinfection by-products(DBPs)during the chlorination process for the safety of drinking water.Therefore,in this study,the effects of AC on the concentration of known DBPs including trihalomethanes(THMs)and haloacetic acids(HAAs)formed during the chlorination of dissolved organic matter(DOM)were compared,and the unknown chlorination byproducts and the transformation of organics in effluent were analyzed by using the Fourier transform ion cyclotron resonance mass spectrometry(FTICR-MS)technique detection.The results showed that during DOM chlorination,lower concentrations of THMs and HAAs were released in the presence of AC,but the rate of chlorine decay was faster,which was due to the strong reducing property of AC itself and the generation of other chlorinated by-products.Further analysis of the unknown chlorinated products and changes in DOM by FTICR-MS revealed that there were 163 identical chlorination products under the two conditions,and 57 of the different chlorination products were generated in the presence of AC compared to the absence of AC.In addition,the numbers of CHOC1,CHONCl,and CHONSCl molecular formulas decreased,while the number of CHOSCl molecular formulas increased,and DOM with an aromatic structure was more easily converted in the presence of AC.The main reason for the change in chlorination products is the generation of chlorine radicals(Cl·)from the reaction of sodium hypochlorite activated by the persistent radicals on the surface of AC through electron spin resonance spectroscopy(ESR)analysis.This study reveals the effects of AC on the generation of DBPs during chlorination,which is important for the control of DBPs in drinking water.
国家科技期刊平台
NSTL
万方数据
