Dual role of soil-derived dissolved organic matter in the sulfamethoxazole oxidation by manganese dioxide

Yang，Biwei1,2; Du，Penghui2; Chen，Guoping2; Zhang，Peng2; Zhang，Qiang2; Wang，Zhongying2; Zhang，Gan3; Cai，Zongwei1; Wang，Junjian2

2023-05-15

10.1016/j.watres.2023.119901

Water Research   Impact Factor & Quartile

0043-1354

1879-2448

Manganese dioxide (MnO) can mediate organic pollutant oxidation in aquatic environments, which has been reported to be inhibited or promoted by dissolved organic matter (DOM) in different studies. It remains unresolved why conflicting results have been observed and whether such results depend on the type and concentration of DOM. Here, we used three types of well-characterized DOM derived from soil heated at 50, 250, or 400 °C (DOM_50, DOM_250, and DOM_400, respectively) to evaluate the impacts of DOM type and concentration and environmental pH on MnO-mediated oxidation of sulfamethoxazole, a widely detected and ecotoxic emerging pollutant. We observed that the degradation rate of sulfamethoxazole was possibly promoted by DOM_250 (pH 6‒8), while it was generally inhibited by DOM_50 and DOM_400. Furthermore, it was initially inhibited and then promoted with increasing DOM concentrations and was consistently less inhibited at a higher pH. The inter-DOM variations of sulfamethoxazole degradation could be explained by the more enriched polyphenolics in DOM_250 than in DOM_50 and DOM_400, whereas the weak promoting effect of DOM_400 indicates that high DOM aromaticity may not necessarily promote pollutant degradation. Our results reconcile the debate on the role of DOM in the oxidation of sulfamethoxazole by MnO and highlight the decisiveness of the molecular composition and concentration of DOM and the reaction pH in the overall promoting or inhibiting role of DOM.

Fourier transform ion cyclotron resonance mass spectrometry Manganese dioxide Oxidation Soil-derived dissolved organic matter Sulfamethoxazole

English

NI Journal Papers

Corresponding

National Natural Science Foundation of China[22206070];National Natural Science Foundation of China[42122054];National Natural Science Foundation of China[42192513];

ENVIRONMENT/ECOLOGY

2-s2.0-85150863242

Scopus

1.State Key Laboratory of Environmental and Biological Analysis,Department of Chemistry,Hong Kong Baptist University,Hong Kong SAR,Hong Kong
2.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,China
3.State Key Laboratory of Organic Geochemistry,Guangdong province Key Laboratory of Environmental Protection and Resources Utilization,and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou,China

Yang，Biwei,Du，Penghui,Chen，Guoping,et al. Dual role of soil-derived dissolved organic matter in the sulfamethoxazole oxidation by manganese dioxide[J]. Water Research,2023,235.

Yang，Biwei.,Du，Penghui.,Chen，Guoping.,Zhang，Peng.,Zhang，Qiang.,...&Wang，Junjian.(2023).Dual role of soil-derived dissolved organic matter in the sulfamethoxazole oxidation by manganese dioxide.Water Research,235.

Yang，Biwei,et al."Dual role of soil-derived dissolved organic matter in the sulfamethoxazole oxidation by manganese dioxide".Water Research 235(2023).