Oxidative capacitance of sulfate-based boron-doped diamond electrochemical system

Farhat, Ali and Keller, Jurg and Tait, Stephan and Radjenovic, Jelena (2018) Oxidative capacitance of sulfate-based boron-doped diamond electrochemical system. Electrochemistry Communications, 89. pp. 14-18. ISSN 1388-2481

Abstract

This study investigates the sustained oxidation performance of sulfate-based electrooxidation at a boron-doped diamond anode; more specifically, the continued oxidation of a model compound, diatrizoate, in the absence of applied current (i.e., off-grid oxidation). Two approaches were taken: delayed sample quenching with methanol, and application of intermittent current supply. For samples electrooxidized in Na2SO4 anolyte for 10–15 min, a delay of 60 min in sample quenching yielded an additional diatrizoate removal of 53%. This impact of sample quenching delay was observed at both pH 2 and pH 7, indicating that the source of sulfate and hydroxyl radicals was present at both pH values. Intermittent current supply (cycles of 5 min ON/15 min OFF) enabled a saving in electrical energy consumption by ~35% compared to constant current, due to continued removal of diatrizoate during the OFF periods. Electrooxidation in NaNO3 anolyte did not show any off-grid oxidation of diatrizoate, confirming the crucial role of electrochemically activated sulfate. Given that the sulfate concentration was only 150 mg L−1, the results presented herein may have significant implications in the electrochemical treatment of various types of contaminated water, from groundwater to sulfate-rich wastewater.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 18 Feb 2019 04:43
Last Modified: 19 Feb 2019 01:31
Uncontrolled Keywords: electrooxidation; sulfate radicals; sustained oxidation performance; radical chain propagation
Fields of Research : 09 Engineering > 0907 Environmental Engineering > 090703 Environmental Technologies
Identification Number or DOI: doi.org/10.1016/j.elecom.2018.02.007
URI: http://eprints.usq.edu.au/id/eprint/35762

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