Carbon isotope fractionation of 1,1,1-trichloroethane during base-catalyzed persulfate treatment

• Published in: Journal of hazardous materials 2013-09, Vol.260, p.61-66
• Main Authors: Marchesi, Massimo, Thomson, Neil R., Aravena, Ramon, Sra, Kanwartej S., Otero, Neus, Soler, Albert
• Format: Article
• Language: English
• Subjects: 1,1,1-Trichloroethane (1,1,1-TCA); Applied sciences; Base-catalyzed persulfate; Carbon isotopes; Carbon Isotopes - metabolism; Catalysis; Catalytic reactions; Chemical engineering; Chemical Fractionation - methods; Chemistry; Degradation; Destruction; Estimates; Exact sciences and technology; Fractionation; General and physical chemistry; Hazardous materials; Hydroxides - chemistry; In situ chemical oxidation (ISCO); Isotope fractionation; Oxygen - chemistry; Performance assessment; Pollution; Reactors; Sodium Compounds - chemistry; Soil Pollutants - analysis; Sulfates - chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Time Factors; Trichloroethanes - chemistry; Water Pollutants, Chemical - analysis
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.05.011

•Treatability and C fractionation of 1,1,1-TCA by base-catalyzed S2O82− was studied.•The rate of degradation of 1,1,1-TCA increased with a higher OH−:S2O82− ratio.•Base-catalyzed S2O82− can potentially treat recalcitrant compound like 1,1,1-TCA.•An enrichment factor of −7.0‰ independent of the OH−:S2O82− ratio was obtained.•Carbon isotope can potentially be used to estimate the ISCO treatment efficacy. The extent of carbon isotope fractionation during degradation of 1,1,1-trichloroethane (1,1,1-TCA) by a base-catalyzed persulfate (S2O82−) treatment system was investigated. Significant destruction of 1,1,1-TCA was observed at a pH of ∼12. An increase in the NaOH:S2O82− molar ratio from 0.2:1 to 8:1 enhanced the reaction rate of 1,1,1-TCA by a factor of ∼5 to yield complete (>99.9%) destruction. An average carbon isotope enrichment fractionation factor which was independent of the NaOH:S2O82− molar ratio of −7.0±0.2‰ was obtained. This significant carbon isotope fractionation and the lack of dependence on changes in the NaOH:S2O82− molar ratio demonstrates that carbon isotope analysis can potentially be used in situ as a performance assessment tool to estimate the degradation effectiveness of 1,1,1-TCA by a base-catalyzed persulfate system.