Mechanisms of 1,4-Dioxane Biodegradation and Adsorption by Bio-Zeolite in the Presence of Chlorinated Solvents: Experimental and Molecular Dynamics Simulation Studies
| Autor: | Shaily Mahendra, Nicholas W. Johnson, Ruihuan Chen, Yun Liu, Cun Liu, Ming Zhong, Yuanhua Dong |
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| Rok vydání: | 2019 |
| Předmět: |
Pollutant
Aqueous solution Sorption General Chemistry 1 4-Dioxane Molecular Dynamics Simulation 010501 environmental sciences Biodegradation 01 natural sciences Dioxanes chemistry.chemical_compound Molecular dynamics Adsorption Chemical engineering chemistry Solvents Zeolites Environmental Chemistry Zeolite Groundwater Water Pollutants Chemical 0105 earth and related environmental sciences |
| Zdroj: | Environmental Science & Technology. 53:14538-14547 |
| ISSN: | 1520-5851 0013-936X |
| Popis: | 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 (Ea/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 Ea/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. |
| Databáze: | OpenAIRE |
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