Hydrogen Sulfide Removal from Biogas Using Pure and Mixed Cultures of Sulfide-Oxidizing Bacteria Biofiltration

Abstract

A novel biofiltration system using pure and mixed cultures of sulfide-oxidizing bacteria immobilized on granular activated carbon (GAC) to purify synthetic and real biogas from a sulfate reaction reactor of concentrated latex industry, contaminated by H₂S, was studied. Complete H₂S removal from synthetic biogas was found in pure and mixed culture reactors at 200 ppm initial H₂S concentration, 35 l h⁻¹ of biogas flow rate and 5.83 l h⁻¹ of airflow rate. H₂S removal using biofiltration had little effect on the methane content of synthetic biogas. Pure and mixed culture reactors at airflow rates of 0.75–5.83 l h⁻¹ also showed complete H₂S removal from real biogas. However, H₂S removal efficiency at the airflow rate of 0.53 l h⁻¹ decreased to 99%. Thus, H₂S removal using biofiltration had little effect on the methane content of real biogas. The results of this study suggest the feasibility of developing using mixed culture of sulfide-oxidizing bacteria from concentrated latex wastewater for industrial application to remove H₂S from biogas through biofiltration.

Keywords:

• Biofiltration
• Hydrogen sulfide
• Sulfide-oxidizing bacteria
• Alcaligenes faecalis T307
• Granular activated carbon

ACKNOWLEDGMENT

This research was supported by Graduate School, Prince of Songkla University and the Education of Shell 100 Years Foundation.