Micro-aeration for hydrogen sulfide reduction in full-scale anaerobic digesters with limited headspace: Performance and sulfide reduction kinetics

A full-scale trial of micro-aeration was conducted at a municipal wastewater plant using two anaerobic digesters with limited headspace, one as a control and one as a test. A reduction of approximately 13 %-16 % in hydrogen sulfide biogas concentrations was observed in the test digester. Microbial community analyses were also conducted at steady-state conditions to determine differences between the microbial ecology of the test and the control digesters. Although sulfide removal typically occurs in the headspace of a micro-aerated digester, the data generated by this pilot study developed a new approach to quantify the contribution of liquid phase sulfide oxidizing microbes (SOM).