Investigating the Reduction of Odorous Agents from Municipal Wastewater Treatment Plants by Biofiltration

Biofilteration is one of the modern technologies in use for controlling the air pollutants because of its cost-effectiveness, high efficiency, simple operation, and lack of generating waste material. The purpose of the present study was to assess the removal or reduction feasibility of odourous compounds through biofilteration system in order to increase the safety and health of the treatment stuffs. A biological reactor having internal diameter of 14 and length of 95 cm was used for 12 months at ambient temperature in the vicinity of the sludge thickner tank. The concentration of compounds such as hydrogen sulfide, ammonia, orgoanosulforo compounds were measured. In order to maintain the suitable conditions for the growth of biomass at the biofilter bed, nutrients were used. The results showed that the removal efficiency of biofilter at an empty bed retention time of 30 and 15 s was more than 97% for hydrogen sulfide. Almost the same result (96%) was achieved for ammonia. According to the laboratory analysis, it was found that origin of odor was emissions of hydrogen sulfide and ammonia gases in the municipal wastewater treatment plant, where the biofilteration system could remove more than 95% of the odourous compounds. Biofilteration could bring the concentration of H2S and NH3 to less than the permitted level as recommended by the National Department of Environment. Therefore, this method is proposed to clean up contaminants in order to control the health and safety of the stuffs working in such environments.