ABSTRACT
Biofiltration offers an efficient and economical alternative for the elimination of offensive odors caused by hydrogen sulfide, ammonia, and volatile organic compounds. Considering that packing materials affect the performance and represent the main installation cost, the purpose of this work was to evaluate the biofiltration of H2S and NH3 comparing three composted mixtures made from chicken manure and lignocellulosic residues (pruning waste, sugarcane bagasse, and rice husk) used as packing material. A range of gas concentrations similar to those of a municipal WWTP was used in the biofiltration of a contaminated stream performed on a laboratory scale. The results indicate that at low concentrations of H2S (6-36 ppm) and NH3 (0-1 ppm), the three biofilters showed 100% removal efficiency. Now, at the maximum levels of gas concentrations of H2S (250 ppm) and NH3 (19 ppm) while the removal efficiency of H2S remained higher than 90% in all cases, the removal efficiency of NH3 remained higher than 90% only in the sugarcane bagasse biofilter. Compost mixtures with sugarcane bagasse and rice husk are highly reliable as packing material for biofiltration at high concentration of H2S. Specifically, the sugarcane bagasse mixture had the highest removal efficiency (99% H2S and 95% NH3) and the highest elimination capacity (15 g H2S/m3h and 0.6 g NH3/m3h), making it a better option for the elimination of both gases. These results represent a contribution to the construction of a low-price elimination system of offensive odors in WTTPs and other industries.
