2024-03-29T02:31:13Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/850222022-11-17T02:08:08Zhdl_2115_20051hdl_2115_144The role of cobalt oxide or magnesium oxide in ozonation of ammonia nitrogen in waterKrisbiantoro, Philip AnggoTogawa, TomokazuMahardiani, LinaAihara, HarukaOtomo, RyoichiKamiya, YuichiOzonationAmmonia nitrogenCobalt oxideMagnesium oxideWastewater treatment431In this study, the reaction mechanisms for ozonation of ammonia nitrogen in the presence of Co3O4 or MgO were investigated. For the reaction over Co3O4, Cl- in the reaction solution was indispensable and ClO- was formed by a non-catalytic oxidation of Cl-. Co3O4 promoted the reaction of NH4+ with ClO- to give the products including NO3-, chloramines and gaseous products. In contrast, Cl- was unnecessary for the reaction with MgO. pH of the reaction solution was maintained at around 9 throughout the reaction owing to partial dissolution of MgO. Ammonia nitrogen was decomposed to mainly NO3(-) by non-catalytic radical reaction involving OH center dot, which was formed by the reaction of OH- with O-3 in weakly basic solution. To keep the reaction solution weakly basic, H+ formed with the decomposition of NH4+ was neutralized. As a result, about the same amount of Mg2+ as that of decomposed ammonia nitrogen was dissolved.ElsevierJournal Articleapplication/pdfapplication/vnd.openxmlformats-officedocument.wordprocessingml.documenthttp://hdl.handle.net/2115/85022https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/85022/2/Manuscript_Appl%20Catal%20A%20Gen_596.pdfhttps://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/85022/3/Supporting%20Information.docx0926-860XAA10821202Applied Catalysis A: General5961175152020-04-25enginfo:doi/10.1016/j.apcata.2020.117515© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 licenseauthor