Experimental Investigation of Biological Removal of H2S from Shiraz Land-Fill Gas

Environment pollution and emission of toxic gases are one of the most important human challenges in the current century. Among polluted gases, land-fill gas with a high percent of methane could be considered as a plentiful source of energy. Biofiltration is a simple and economical method for removal of some contaminants such as hydrogen sulfide which is strongly toxic and corrosive. In this method, sweetening is done by passing the polluted gas through the bed of microorganism. For this purpose, a biofilter column of plexi glass with 15cm internal diameter and 2 m height was designed and constructed. The bed of this column was vermicompost mixed with the seashell. Then Thiobacillus thioparus bacteria which is cultured in the lab was previously, stabilized on the surface of the filling. The ability of this biofilter in 30 ppm concentration of H2S and different flow rate of landfill gas, in ambient temperature and atmospheric pressure, was studied. According to the experiments, it is observed that during 2 minutes, the yield is higher than 80%. In this condition, the concentration of H2S is desirable. Of course, in the study, the efficiency of biofilter in 30 ppm of H2S and flow rate of 2 L/min of polluted gas, was about 90 percent.