Seid, Mingizem Gashaw Lee, Changha Cho, Kangwoo Hong, Seok Won 2024-01-19T14:01:31Z 2024-01-19T14:01:31Z 2021-10-21 2021-09 0043-1354 https://pubs.kist.re.kr/handle/201004/116536 This study investigated the effects of thirteen (photo/electro) chemical oxidation processes on the formation potential (FP) of N-nitrosodimethylamine (NDMA) during the chloramination of ranitidine in reverse osmosis (RO) permeate and brine. The NDMA-FP varied significantly depending on the pretreatment process, initial pH, and water matrix types. At higher initial pH values (> 7.0), most pretreatments did not reduce the NDMA-FP, presumably because few radical species and more chloramine-reactive byproducts were generated. At pH < 7.0, however, electrochemical oxidation assisted by chloride and Fe2+/H2O2, catalytic wet peroxide oxidation and peroxydisulfate-induced pretreatments removed up to 85% of NDMA-FP in the RO brine. Ultraviolet (UV) irradiation or prechlorination alone did not reduce the NDMA-FP effectively, but combined UV/chlorine treatment effectively reduced the NDMA-FP. In contrast, after UV irradiation (2.1 mW cm(-2) for 0.5 h) in the presence of H2O2 and chloramine, NDMA formation increased substantially (up to 26%) during the post-chloramination of the RO permeate. Mass spectrometric analysis and structural elucidation of the oxidation byproducts indicated that compared with the reactive nitrogen species generated by UV/NH2Cl, sulfate radicals and (photo/electro) chemically generated reactive chlorine species were more promising for minimizing NDMA-FP. Unlike, the hemolytic center dot OH driven by UV/H2O2, the center dot OH from Fe(IV)-assisted pretreatments showed a significant synergistic effect on NDMA-FP reduction. Overall, the results suggest the need for a careful assessment of the type of radical species to be used for treating an RO water system containing amine-functionalized compounds. English PERGAMON-ELSEVIER SCIENCE LTD Degradation of ranitidine and changes in N-nitrosodimethylamine formation potential by advanced oxidation processes: Role of oxidant speciation and water matrix Article 10.1016/j.watres.2021.117495 1 WATER RESEARCH, v.203 WATER RESEARCH 203 N scie scopus 000697760700003 2-s2.0-85113256841 Engineering, Environmental Environmental Sciences Water Resources Engineering Environmental Sciences & Ecology Water Resources Article NDMA FORMATION REVERSE-OSMOSIS ELECTRO-FENTON POTABLE REUSE BY-PRODUCTS WASTE PHARMACEUTICALS PERSULFATE KINETICS CHLORINE N-nitrosodimethylamine formation potential Reactive radical species (Photo/electro)chemical oxidation Ranitidine chloramination Reverse osmosis