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Mechanistic Study on Size Exclusion of NOM onto Porous TiO 2 for Target Contaminants Decomposition
Author(s) -
Zakersalehi Abolfazl,
Zamankhan Hesam,
Nadagouda Mallikarjuna,
Choi Hyeok
Publication year - 2017
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143017x15051465918967
Subject(s) - mesoporous material , natural organic matter , chemistry , porosity , decomposition , photocatalysis , humic acid , chemical engineering , polyethylene glycol , water treatment , contamination , selectivity , organic matter , environmental chemistry , catalysis , organic chemistry , environmental engineering , environmental science , ecology , fertilizer , engineering , biology
Nonselective oxidation of organic chemicals during TiO 2 photocatalytic water treatment significantly prohibits decomposition of toxic target contaminants, particularly in the presence of naturally abundant less toxic natural organic matter (NOM). To minimize the adverse effect of NOM, the authors have investigated physical size exclusion of large NOM onto mesoporous TiO 2 photocatalysts, which allows small target contaminants to selectively access the porous structure for subsequent chemical reaction. Various treatment scenarios tested with different targets (ibuprofen, microcystin‐LR) and competitors (humic acid, polyethylene glycol), and a series of mesoporous TiO 2 materials proved the size exclusion mechanism. Discussion was made on the impact of the porous structure of TiO 2 on selectivity and reactivity, considering size difference among targets < TiO 2 pores < competitors as well as mass transfer limitation of even a target to small pores. This simple approach would greatly improve the photocatalytic treatment of toxic chemicals in water containing NOM.