Seid, Mingizem Gashaw Byun, Jeehye Kim, Wooyul Cho, Kangwoo Hong, Seok Won 2024-01-19T13:00:49Z 2024-01-19T13:00:49Z 2022-01-10 2022-02 0304-3894 https://pubs.kist.re.kr/handle/201004/115797 We investigated the effectiveness of photocatalytic pretreatment (PCP) of precursors in minimizing the formation potentials (FPs) of carcinogenic nitrosamines, including N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), and N-nitrosodiethanolamine (NDELA), during water chloramination. A steel mesh substrate with immobilized TiO2 was highly efficient at mitigating nitrosamine formation and removing targeted precursors such as ranitidine, nizatidine, trimebutine, triethanolamine, and metoclopramide. Compared to UVC/H2O2, PCP under UVA irradiation (intensity of 0.67 mW cm(-2)) was more effective for reducing nitrosamine-FPs during post-chloramination. However, the PCP efficacies varied with the water source, pretreatment pH, and irradiation time. For example, PCP of eutrophic water increased the NDMA-FPs, but produced notable reductions (up to 99%) for NDELA-and NDEA-FPs. Shorter irradiation times, up to 15 min, increased the NDELA-FP in triethanolamine, and the NDMA-FP in nizatidine and trimebutine. However, the nitrosamine-FP decreased by > 50% after PCP at a pH > 5.6, following irradiation for 120 min. Oxygen addition, N-de(m)ethylation, and N-dealkylation were responsible for decreasing nitrosamine-FPs via the destruction of key moieties; this has been elucidated by mass spectroscopy. This study suggests that PCP could be used as an alternative strategy for minimizing nitrosamine-FPs during water treatment. English Elsevier BV Changes in levels of N-nitrosamine formed from amine-containing compounds during chloramination via photocatalytic pretreatment with immobilized TiO2: Effect of source water and pH Article 10.1016/j.jhazmat.2021.127398 1 Journal of Hazardous Materials, v.424 Journal of Hazardous Materials 424 N scie scopus 000711802000001 2-s2.0-85116695231 Engineering, Environmental Environmental Sciences Engineering Environmental Sciences & Ecology Article NDMA FORMATION WASTE-WATER NITROSODIMETHYLAMINE NDMA ALIPHATIC-AMINES BY-PRODUCTS DEGRADATION PHARMACEUTICALS SOLAR OXIDATION PRECURSORS N-nitrosamine formation potential Pharmaceuticals Photocatalysis Reaction pathways Triethanolamine