Simultaneous elimination of H2S and NH3 in a biotrickling filter packed with polyhedral spheres and best efficiency in compost deodorization

Abstract With polyhedral spheres as the packing, a semi-pilot biological trickling filter reactor (BTF) inoculated by domesticated activated sludge is used to remove Hydrogen Sulphide (H2S) and Ammonia (NH3). The removal rate of H2S and NH3 by BTF was as high as 98.25% and 88.55%, and the maximum removal load was 84.57 g H2S m−3h−1 and 38.77 g NH3 m−3h−1 during the 61-day process. The inlet gas concentration ranges from 0 to 500 ppm, and the empty bed residence time (EBRT) is 31.8 s. When the EBRT reduced from 31.8s to 25.4s, the removal rate of H2S and NH3 decreased significantly, which was 67.21% and 81.36%, respectively. The results showed that EBRT significantly affected the removal rate of H2S and NH3. Microbial analysis indicated that Dokdonella, Ferruginibacter, Nitrosomonas, and Thiobacillus had high abundance at the genus level, showing that these genera play an important role in the degradation of H2S and NH3. When the optimized parameters applied to the on-site biogas residue compost, the removal rate of H2S and NH3 by BTF can reach 91.34%, which provides a feasible process for the deodorization project with compost.