Sulfide Transformation during the Intermittent Contact Oxidation Process

Abstract

A byproduct of anaerobic domestic wastewater treatment is sulfide species which, when left untreated, can result in malodor and increased pollutant load in the water environment. In this study, the intermittent contact oxidation process (ICOP) is proposed as a post-treatment process for anaerobic treatment effluent because it enables passive treatment that supports positive energy yield for anaerobic domestic wastewater treatment. The objective of this study is to evaluate sulfide oxidation via the ICOP focusing on the mechanism of sulfide oxidation with intermittent wastewater flow. A mass balance analysis of a channel with porous sponge media installed was used to evaluate sulfide, oxidized sulfur intermediate, and sulfate species during the treatment of synthetic wastewater containing sulfide. It was found through the mass balance analysis that sulfide was removed from the feed through retention and eventual oxidation to sulfate. Sulfide oxidation then occurred via biological and chemical means where biological oxidation contributed to faster oxidation. The rate of sulfide oxidation during the ICOP was evaluated on a per area basis where the sulfide removal rate was 5.5 E.7 g S m∁E d∁E. The findings underscore the extent of sulfide oxidation during the ICOP which can expand post-treatment options for streams containing sulfide.

Keywords

• sulfide
• sulfide oxidation
• self-purification