Comparative study of using different materials as bacterial carriers to treat hydrogen sulfide

The use of support media for the immobilization of microorganisms is widely known to provide a surface for microbial growth and protect the microorganisms from inhibitory compounds. In this study, molecular sieve, granular porous carbon, and ferric oxide desulfurizer, immobilized with autotrophic bacteria capable of oxidizing ferrous iron to ferric iron, were developed to treat hydrogen sulfide (H2S). Their corresponding bioreactors were referred to as BMS, BPC, and BFO, respectively. H2S loading, gas retention time, hydrogen ion, and aluminous, ferric, and ferrous iron concentrations of recycling effluents were evaluated. Thermogravimetric analysis, Brauner-Emmett-Teller method, and scanning electron microscopy were used to characterize packing materials. Results showed that the elimination capacity was in the order of BFO > BPC > BMS. This study suggested that the material characteristics progressively influenced the deodorization capacities of bioreactors. H2S was oxidized into elemental sulfur and oxidized sulfur species, according to differences of carriers. Furthermore, this study revealed the potential application of simultaneously treating of H2S under extremely acidic conditions.