Enhanced Removal Efficiency of Malodorous Gases in Pilot-Scale Peat Biofilter Inoculated with Thiobacillus thioparus DW44

Abstract

Sulfur-containing gases like hydrogen sulfide(H2S), methanethiol(MT), dimethyl sulfide(DMS) and dimethyl disulfide(DMDS), cause an environmental problem in night soil treatments. Pilot-scale peat biofilters had been operated to treat the exhaust gases in the two night soil treatment plants[1–3]. Through these field experiments, the following problems have been remained unsolved; 1) an acclimation period for growth of microorganisms responsible for degradation of these gases was rather long, two weeks to six months. 2) DMS is less biodegradable compared with the other gases. Thus, breeding of effective microorganisms, which are capable to degrade H2S, MT, DMS and DMDS is one of the prominent means to overcome these problems. We had already isolated T.thioparus DW44, capable of degrading these gases, and confirmed its removability of the gases in a laboratory-scale peat biofilter[4]. In this study, T.thioparus DW44 was inoculated into a pilot-scale peat biofilter and the removability of these gases exhausted from a night soil treatment plant was investigated for nine months.KeywordsPilot-scale peat biofilter Thiobacillus thioparus night soil treatment plantmalodorous sulfur-containing gases