The Evaluation of Acclimate Thiobacillus thioparus in Removal Hydrogen Sulfide from Polluted Air

Microorganism activity in the biological reactor converts contaminants to harmless products. Bio-filter is a continuous biological reactor and a new technology for decomposing different contaminants. This study aimed to evaluate of acclimatization Thiobacillus thioparus to removal hydrogen sulfide in a bio-filteration system with used seashell for packing media. For reproduction and microbial activation, it require to prepare special culture medium, vitamin and trace elements solution. After made three solutions we cultivate the bacteria. The bio-filter column were constructed using transparent plexyglass with a height of 40 cm and diameter of 15 cm and bed depth of 27.5 cm, fulled by seashell packing media. The porosity of seashell packing media is 63 percent. Bio-filter has four inlet pipes in above space. This pipes use for injecting air flow, injecting polluted gas, effluent readings for H2S, injecting nutrient and culture medium. Bacterial activity have been surveyed for 15 week and removal efficiency by T. thioparus were evaluated and various concentrations, less than 20 mg/m3 to more than 100 mg/m3. The best performance observed in 29oC. Also optimum pH was 7-7.5 for a stable system. The number of measured samples were 550 and for each concentration at least 6 reading at different time. The results observed that, the removal efficiency was increasing so the adaptation process was increasing. It was possible that increase of concentration inlet polluted gas without affect on the removal efficiency. It means that the bio-filter is stable. The obtained results observed that polluted gas concentration has not significant effects on gas treatment process and removal efficiency were 78-88 percent, when the T. thioparus acclimated in the desirable conditions for removal polluted gas. Also removal efficiency will remain well when the humidity rate was 77-93 percent and temperature was 20.5-30oC in growth and reproduction of T. thioparus. When T. thioparus acclimated and obtained stable conditions in seventh week, biomass production rate would be increasing and upward until fifthly week.