Degradation of 1, 4-dioxane by hydroxyl radicals produced from clay minerals

Qiang Zeng; Hailiang Dong; Xi Wang; Tian Yu; Weihua Cui

doi:10.1016/j.jhazmat.2017.01.040

Degradation of 1, 4-dioxane by hydroxyl radicals produced from clay minerals

J Hazard Mater. 2017 Jun 5:331:88-98. doi: 10.1016/j.jhazmat.2017.01.040. Epub 2017 Feb 11.

Authors

Qiang Zeng¹, Hailiang Dong², Xi Wang¹, Tian Yu³, Weihua Cui⁴

Affiliations

¹ Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China.
² Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; Department of Geology and Environmental Earth Science, Miami University, OH 45056, USA. Electronic address: dongh@cugb.edu.cn.
³ Geomicrobiology Laboratory, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China.
⁴ School of Water Resources and Environment, China University of Geosciences, Beijing 100083, PR China.

PMID: 28249183
DOI: 10.1016/j.jhazmat.2017.01.040

Abstract

1,4-Dioxane is causing a general concern as an emerging contaminant in groundwater environment. Traditional remediation methods can be either inefficient or costly. In this study, we present a cost effective method for possible in situ remediation of 1,4-dioxane. Hydroxyl radicals (OH) produced from oxygenation of structural Fe(II) in ferruginous clay minerals significantly degraded high concentrations of 1,4-dioxane (up to 400μmol/L) within 120h under circumneutral pH and dark condition. The amount of 1,4-dioxane degradation was positively correlated with the amount of OH. The major degradation product of 1,4-dioxane was formic acid. Different clay mineral types, initial Fe(II) concentration, and buffer composition all affected OH production and 1,4-dioxane degradation efficiency. Nontronite, an iron-rich smectite, was a reusable and effective material for sustainable production of OH and 1,4-dioxane degradation, through regeneration of Fe(II) either biologically or chemically. The non-selectivity and strong oxidative power of OH make it a promising agent for remediating various kinds of organic contaminants in aqueous environment.

Keywords: 1,4-Dioxane; Clay minerals; Hydroxyl radical; Recyclability.