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Environ Sci Technol

Title:		"Mechanisms of 1,4-Dioxane Biodegradation and Adsorption by Bio-Zeolite in the Presence of Chlorinated Solvents: Experimental and Molecular Dynamics Simulation Studies"
Author(s):		Liu Y; Johnson NW; Liu C; Chen R; Zhong M; Dong Y; Mahendra S;
Address:		"Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science , Chinese Academy of Sciences , Nanjing 210008 , Jiangsu , China. Civil and Environmental Engineering , University of California, Los Angeles , Los Angeles 90095 , California , United States. University of Chinese Academy of Sciences , Beijing 100000 , Hebei , China"
Journal Title:		Environ Sci Technol
Year:		2019
Volume:		20191122
Issue:		24
Page Number:		14538 - 14547
DOI:		10.1021/acs.est.9b04154
ISSN/ISBN:		1520-5851 (Electronic) 0013-936X (Linking)
Abstract:		"The use of bioaugmented zeolite (bio-zeolite) can be an effective technology for irreversibly removing recalcitrant organic pollutants in aqueous mixtures. Removal of 1,4-dioxane by a bio-zeolite (Pseudonocardia dioxanivorans CB1190-bioaugmented ZSM-5) in the presence of several chlorinated volatile organic compounds (CVOCs) was superior to removal by adsorption using abiotic zeolite. Mixtures containing 1,1-dichloroethene (1,1-DCE) were an exception, which completely inhibited the bio-zeolite system. Specific adsorption characteristics were studied using adsorption isotherms in single-solute and bisolute systems accompanied by Polanyi theory-based Dubinin-Astakhov (DA) modeling. Adsorption behavior was examined using characteristic energy (E(a/H)) from modified DA models and molecular dynamics simulations. While the tight-fit of 1,4-dioxane in the hydrophobic channels of ZSM-5 appears to drive 1,4-dioxane adsorption, the greater hydrophobicity of trichloroethene and cis-1,2-dichloroethene cause them have a greater affinity over 1,4-dioxane for adsorption sites on the zeolite. 1,4-Dioxane was desorbed and displaced by CVOCs except 1,1-DCE because of its low E(a/H) value, explaining why bio-zeolite only biodegraded 1,4-dioxane in 1,1-DCE-free CVOC mixtures. Understanding the adsorption mechanisms of solutes in complex mixtures is crucial for the implementation of sorption-based treatment technologies for the removal of complex contaminant mixtures from aquatic environments"
Keywords:		"Adsorption Dioxanes *Groundwater Molecular Dynamics Simulation Solvents *Water Pollutants, Chemical *Zeolites;"
Notes:		"MedlineLiu, Yun Johnson, Nicholas W Liu, Cun Chen, Ruihuan Zhong, Ming Dong, Yuanhua Mahendra, Shaily eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2019/10/31 Environ Sci Technol. 2019 Dec 17; 53(24):14538-14547. doi: 10.1021/acs.est.9b04154. Epub 2019 Nov 22"