Biofiltration of hydrogen sulfide-containing waste gas by entrapped mixed microbial cells

The study demonstrates a novel attempt to use an aerobic biofiltration system containing entrapped mixed microbial cells (EMMC) for removal of hydrogen sulfide dominant waste gases. In the study, heterotrophic microflora-immobilized cellulose was packed into an EMMC reactor to degrade hydrogen sulfide. Effects of hydrogen sulfide concentrations for continuous operation at various flow rates indicated that hydrogen sulfide removal efficiency is higher than 90% at inlet loadings below 4.31 mg-S/min for retention time of 5.3 minutes. This EMMC biofiltration system also showed high tolerance to fluctuations in flow rates while maintaining stable removal performance. The predicted kinetic constant k and maximum mass loading are 0.018 s-1 and 8.64 mg-S/min, respectively. Adaptability tests in response to gradual shifts up and down of inlet hydrogen sulfide loading indicated that the EMMC microbial communities were well-acclimated to maintain long-term operation stability for continuous treatment.