Cyclodextrin-enhanced 1,4-dioxane treatment kinetics with TCE and 1,1,1-TCA using aqueous ozone

Naima A Khan; Michael D Johnson; James D Kubicki; F Omar Holguin; Barry Dungan; Kenneth C Carroll

doi:10.1016/j.chemosphere.2018.11.200

Cyclodextrin-enhanced 1,4-dioxane treatment kinetics with TCE and 1,1,1-TCA using aqueous ozone

Chemosphere. 2019 Mar:219:335-344. doi: 10.1016/j.chemosphere.2018.11.200. Epub 2018 Nov 29.

Authors

Naima A Khan¹, Michael D Johnson², James D Kubicki³, F Omar Holguin⁴, Barry Dungan⁴, Kenneth C Carroll⁵

Affiliations

¹ Water Science and Management Program, New Mexico State University, MSC 3Q P.O. Box 30003, Las Cruces, NM 88003, USA; Plant & Environmental Science, New Mexico State University, MSC 3Q P.O. Box 30003, Las Cruces, NM 88003, USA.
² Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C P.O. Box 30001, Las Cruces, NM 88003, USA.
³ Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968-0555, USA.
⁴ Plant & Environmental Science, New Mexico State University, MSC 3Q P.O. Box 30003, Las Cruces, NM 88003, USA.
⁵ Water Science and Management Program, New Mexico State University, MSC 3Q P.O. Box 30003, Las Cruces, NM 88003, USA; Plant & Environmental Science, New Mexico State University, MSC 3Q P.O. Box 30003, Las Cruces, NM 88003, USA. Electronic address: kccarr@nmsu.edu.

PMID: 30551099
DOI: 10.1016/j.chemosphere.2018.11.200

Abstract

Enhanced reactivity of aqueous ozone (O₃) with hydroxypropyl-β-cyclodextrin (HPβCD) and its impact on relative reactivity of O₃ with contaminants were evaluated herein. Oxidation kinetics of 1,4-dioxane, trichloroethylene (TCE), and 1,1,1-trichloroethane (TCA) using O₃ in single and multiple contaminant systems, with and without HPβCD, were quantified. 1,4-Dioxane decay rate constants for O₃ in the presence of HPβCD increased compared to those without HPβCD. Density functional theory molecular modeling confirmed that formation of ternary complexes with HPβCD, O₃, and contaminant increased reactivity by increasing reactant proximity and through additional reactivity within the HPβCD cavity. In the presence of chlorinated co-contaminants, the oxidation rate constant of 1,4-dioxane was enhanced. Use of HPβCD enabled O₃ reactivity within the HPβCD cavity and enhanced 1,4-dioxane treatment rates without inhibition in the presence of TCE, TCA, and radical scavengers including NaCl and bicarbonate. Micro-environmental chemistry within HPβCD inclusion cavities mediated contaminant oxidation reactions with increased reaction specificity.

Keywords: 1,4-dioxane; Advanced oxidation; Cyclodextrin; Groundwater contamination; Groundwater remediation; Ozone.

MeSH terms

2-Hydroxypropyl-beta-cyclodextrin / pharmacology*
Dioxanes / pharmacology*
Groundwater / chemistry
Kinetics
Oxidation-Reduction
Ozone* / chemistry
Trichloroethanes / pharmacology
Trichloroethylene / pharmacology
Water Pollutants, Chemical / analysis
Water Pollutants, Chemical / chemistry
Water Purification / methods*

Substances

Dioxanes
Trichloroethanes
Water Pollutants, Chemical
1,1,1-trichloroethane
2-Hydroxypropyl-beta-cyclodextrin
Trichloroethylene
Ozone
1,4-dioxane