title: Effect of oxidation on amine-based pharmaceutical degradation and N-Nitrosodimethylamine formation.
abstract: Four pharmaceuticals (ranitidine, nizatidine, doxylamine, and carbinoxamine) were selected as model compounds to assess the efficiency of four oxidants (ozone (O3), chlorine (Cl2), chlorine dioxide (ClO2) and potassium permanganate (KMnO4)) on the removal of amine-based pharmaceutical and personal care products (PPCPs), as well as the reduction of their N-Nitrosodimethylamine formation potentials (NDMAFPs). The changes in PPCPs and their NDMAFPs during oxidation were quantified using various oxidants and dosages. The relationship between oxidation product structures and NDMAFP changes was also analyzed. The results showed that oxidation with O3, Cl2 and ClO2 were effective in removing the selected PPCPs. However, only ozonation was effective in reducing their NDMAFPs. Ozonation at 6 mg/L removed approximately 90% PPCPs and 90% NDMAFPs for all PPCPs. In addition, the results indicated that ozonation products made little contribution to NDMAFPs. In contrast, some PPCP products had higher NDMAFPs than PPCPs after oxidation with Cl2, ClO2 and KMnO4. There were two possible reaction pathways that led to decrease in NDMAFPs after oxidation. One was oxygen transfer to nitrogen at the tertiary amine site and the other was N-dealkylation from the tertiary amine site.
authors.affiliation: Department of Environmental Engineering, School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: yanghw@tsinghua.edu.cn.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China.
authors.forename: Beihai
authors.initials: B
authors.lastname: Zhou
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaomao
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China; Civil and Environmental Engineering Programs, Pennsylvania State University, Middletown, PA 17057, USA.
authors.forename: Yuefeng
authors.initials: Y
authors.lastname: Xie
mesh_terms: D004128:Dimethylnitrosamine / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000737:chemistry; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D016877:Oxidants; D004364:Pharmaceutical Preparations; D014874:Water Pollutants, Chemical; D004128:Dimethylnitrosamine
keywords: Chlorine; Chlorine dioxide; NDMA; Ozone; PPCPs; Potassium permanganate