Final products and kinetics of biochemical and chemical sulfide oxidation under microaerobic conditions

Abstract

Hydrogen sulfide is a toxic and usually undesirable by-product of the anaerobic treatment of sulfate-containing wastewater. It can be removed through microaeration, a simple and cost-effective method involving the application of oxygen-limiting conditions (i.e., dissolved oxygen below 0.1 mg L−1). However, the exact transformation pathways of sulfide under microaerobic conditions are still unclear. In this paper, batch experiments were performed to study biochemical and chemical sulfide oxidation under microaerobic conditions. The biochemical experiments were conducted using a strain of Sulfuricurvum kujiense. Under microaerobic conditions, the biochemical sulfide oxidation rate (in mg S L−1 d−1) was approximately 2.5 times faster than the chemical sulfide oxidation rate. Elemental sulfur was the major end-product of both biochemical and chemical sulfide oxidation. During biochemical sulfide oxidation elemental sulfur was in the form of white flakes, while during chemical sulfide oxidation elemental sulfur created a white suspension. Moreover, a mathematical model describing biochemical and chemical sulfide oxidation was developed and calibrated by the experimental results.

Analysis of Biogas Component Production during Anaerobic Digestion of Sour Cabbage in Microaeration Conditions under Different pH Conditions

“…On the OFR analysis, there can be observed that the fermentation of sour cabbage hydrogen production is more sensitive than methane production. This showed that in the case of high VSS [75] there were some ranges improving methane production yield that agreed with comparisons of Nguyen et al [25] (fixing metabolism in the anaerobic digestion of lignocellulose), and Krayzelova et al [76] (reduction of hydrogen sulfide). It can be discerned that after the 11 th day (265 hours) a significant growth of hydrogen production was observed -see Figure 4, due to pH decrease (to 5.1).…”

Sulfate-rich wastewater treatment using an integrated anaerobic/aerobic biological system

“…Sulfur is expected to be the primary end product of biological sulfide-oxidation for oxygen concentrations below 0.1 mg/L, with partial oxidation to thiosulfate. With higher oxygen availability, sulfate is expected to be the predominant end-product (Pokorna-Krayzelova et al, 2018). The amount of dissolved oxygen can be associated with the aeration rate and the use in the biochemical reaction; hence, optimizing aeration is crucial to prevent low or incomplete sulfideoxidation (Pokorna & Zabranska, 2015).…”

Biological H2S removal from gases

“…In Pokorna-Krayzelova et al (2017b), ADM1 was extended by sulfur reactions (sulfate reduction and sulfide oxidation) in anaerobic/microaerobic fermenters. The resulting model ADM1-S/O was later extended by chemical oxidation of hydrogen sulfide (Pokorna-Krayzelova et al, 2018b).…”