Investigation of sulfide removal using biofilter innoculated with sulfur oxidizing bacteria (SOB)

Abstract

Hydrogen sulfide (H2S) is an odor gas that is harmful to senses of human and the environment if the amount exceeds 7.5 mg/Nm3 (QCVN 19:2009/BTNMT). In this study, hydrogen sulfide was treated by three strains of Sulfur Oxidizing Bacteria (SOB) using perlite as substrate for biofilter. Three strains of SOB: Microbacterium hominis, Ochrobactrum intermedium and undefined bacteria WH3 were immobilized on perlite in both treatments. There were two treatments for evaluating the ability to remove hydrogen sulfide of SOB. In one treatment, bacteria are provided nutrition by TSB medium. The other treatment was discarded medium and fill with distilled water to make poor nutritional condition. Based on the nutritional condition between two treatments, the degree of absorption of SOB was evaluated. The result of two treatments indicated three strains of SOB had capability of removing 40% - 70% of hydrogen sulfide. Among them, Microbacterium hominis was the most effective in reducing 33.06 mg/L of hydrogen sulfide after 6 days. Also, the change in density of bacteria after 6 days affected to the ability to remove hydrogen sulfide. The more bacteria growth, the more hydrogen sulfide concentration was remove. Key word Sulfur Oxidizing Bacteria (SOB), Microbacterium hominis, Ochrobactrum intermedium, Undefined bacteria WH3, Hydrogen Sulfide, Biofilter, Perlite