Enhancing the Biological Oxidation of H2S in a Sewer Pipe with Highly Conductive Concrete and Electricity-Producing Bacteria

Abstract

Hydrogen sulfide (H2S) generated in sewer systems is problematic to public health and the environment, owing to its corrosive consequences, odor concerns, and poison control issues. In a previous work, conductive concrete, based on amorphous carbon with a mechanism that operates as a microbial fuel cell was investigated. The objective of the present study is to develop additional materials for highly conductive concrete, to mitigate the concentration of H2S in sewer pipes. Adsorption experiments were conducted to elucidate the role of the H2S reduction. Additionally, electricity-producing bacteria (EPB), isolated from a municipal wastewater treatment plant, were inoculated to improve the H2S reduction. The experimental results showed that inoculation with EPB could decrease the concentration of H2S, indicating that H2S was biologically oxidized by EPB. Several types of new materials containing acetylene black, or magnetite were discovered for use as conductive concrete, and their abilities to enhance the biological oxidation of H2S were evaluated. These conductive concretes were more effective than the commercial conductive concrete, based on amorphous carbon, in decreasing the H2S concentration in sewer pipes.

Hydrogen sulphide

“…Scavengers such as zinc oxide (ZnO), copper(II) nitrate trihydrate (Cu(NO 3 )₂Á3H₂O) and potassium permanganate (KMnO 4 ) of varying mass concentrations in drilling mud have been used historically to reduce the threat posed by H₂S in drilling fluids when they are cycled during oil and gas drilling operations [70]. Further, it has been established that in sewer pipes, the combination of conductive concrete containing magnetite, and the presence of electricity-producing bacteria reduces the concentration of H₂S [71].…”