Deodorization of gases emitted from Tanneries using eco-friendly and cost-effective approaches is necessary for the safe disposal of industrial emissions. There is limited research available on the treatment of odorous gases emitted from tanneries using bio-filter. In this endeavor, pilot-scale studies were performed in a 2.7 m3 bio-filter with synthetic gas mixture containing hydrogen sulfide (H2S) and ammonia (NH3) as input gas to study the impact of bedding material for the removal of H2S and NH3 using bio-filter and identification of various design parameters for scale-up. The pilot-scale studies showed that the removal efficacy of both NH3 and H2S was about 90-99% at an empty bed residence time of 55 seconds at an inlet concentration (NH3 and H2S) of 200 to 210 ppmV and microbial count enhanced from 3.5 × 103 to 8.9 × 109 in 210 days. The microbial biodiversity analysis revealed the dominance of proteobacteriaas as well as Firmicutes and Acinetobacter. A full-scale bio-filter (13.75 m3) was designed, installed, and commissioned in a tannery and observed that the removal efficiency of >99% since last three years.
Keywords: Biofilter; H2S; NH3; full-scale; microbial diversity; odor; pilot-scale.