Transformation of m-aminophenol by birnessite (δ-MnO2) mediated oxidative processes: Reaction kinetics, pathways and toxicity assessment

Wenqian Huang; Guowei Wu; Hong Xiao; Haiyan Song; Shuzhao Gan; Shuhong Ruan; Zhihong Gao; Jianzhong Song

doi:10.1016/j.envpol.2019.113408

Transformation of m-aminophenol by birnessite (δ-MnO₂) mediated oxidative processes: Reaction kinetics, pathways and toxicity assessment

Environ Pollut. 2020 Jan:256:113408. doi: 10.1016/j.envpol.2019.113408. Epub 2019 Oct 19.

Authors

Wenqian Huang¹, Guowei Wu¹, Hong Xiao¹, Haiyan Song², Shuzhao Gan¹, Shuhong Ruan¹, Zhihong Gao¹, Jianzhong Song³

Affiliations

¹ School of Chemistry and Environment, South China Normal University, Universities Town, Guangzhou, 510006, PR China.
² School of Chemistry and Environment, South China Normal University, Universities Town, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academic of Sciences, Guangzhou, 510640, PR China; Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, South China Normal University, Guangzhou, 510006, PR China. Electronic address: songhaiyan@m.scnu.edu.cn.
³ State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China.

PMID: 31662267
DOI: 10.1016/j.envpol.2019.113408

Abstract

The m-aminophenol (m-AP) is a widely used industrial chemical, which enters water, soils, and sediments with waste emissions. A common soil metal oxide, birnessite (δ-MnO₂), was found to mediate the transformation of m-AP with fast rates under acidic conditions. Because of the highly complexity of the m-AP transformation, mechanism-based models were taken to fit the transformation kinetic process of m-AP. The results indicated that the transformation of m-AP with δ-MnO₂ could be described by precursor complex formation rate-limiting model. The oxidative transformation of m-AP on the surface of δ-MnO₂ was highly dependent on reactant concentrations, pH, temperature, and other co-solutes. The UV-VIS absorbance and mass spectra analysis indicated that the pathway leading to m-AP transformation may be the polymerization through the coupling reaction. The m-AP radicals were likely to be coupled by the covalent bonding between unsubstituted C2, C4 or C6 atoms in the m-AP aromatic rings to form oligomers as revealed by the results of activation energy and mass spectra. Furthermore, the toxicity assessment of the transformation productions indicated that the toxicity of m-AP to the E. coli K-12 could be reduced by MnO₂ mediated transformation. The results are helpful for understanding the environmental behavior and potential risk of m-AP in natural environment.

Keywords: Degradation kinetics; Pathway; m-Aminophenol; δ-MnO(2).

MeSH terms

Aminophenols / chemistry*
Aminophenols / toxicity
Escherichia coli
Kinetics
Manganese Compounds
Oxidation-Reduction
Oxidative Stress
Oxides / chemistry*
Water
Water Pollutants, Chemical / chemistry*
Water Pollutants, Chemical / toxicity

Substances

Aminophenols
Manganese Compounds
Oxides
Water Pollutants, Chemical
birnessite
Water
3-aminophenol