Simultaneous biofiltration of H2S, NH3 and toluene using cork as a packing material

Abstract

Simultaneous removal of ternary gases of NH 3 , H 2 S and toluene in a contaminated air stream was investigated over 185 days in a biofilter packed with cork as microbial support. Multi-microorganisms including Nitrosomonas and Nitrobactor for nitrogen removal, Thiobacillus thioparus (ATCC 23645) for H 2 S removal and Pseudomonas aeruginosa (ATCC 15692), Pseudomonas putida (ATCC 17484) and Pseudomonas putida (ATCC 23973) for toluene removal were used simultaneously. The empty bed residence time (EBRT) was 40-120 seconds and the inlet feed concentration was 50-180 ppmv for NH 3 , 30-160 ppmv for H 2 S and 40-130 ppmv for toluene, respectively. The observed removal efficiency was 45-100% for NH 3 , 96-100% for H 2 S, and 10-99% for toluene, respectively. Maximum elimination capacity was 5.5 g/m 3 /hr for NH 3 , >20.4 g/m 3 /hr for H 2 S and 4.5 g/m 3 /hr for toluene, respectively. During longterm operation, the removal efficiency of toluene gradually decreased, mainly due to depositions of elemental sulfur and ammonium sulfate on the cork surface. The results of microbial analysis showed that nearly the same population density was observed on the surfaces of cork chips collected at each sampling point. Kinetic model analyses showed that there were no particular evidences of interactions or inhibitions among the microorganisms.

Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species

“…However, in recent years biological technologies, and in particular biofiltration, have been promoted as providing the most effective methods of air pollution control [6,7]. This is due to the inherent advantages which include low capital, and maintenance, costs; energy efficiency; reduced, or eliminated, requirements for chemicals; and good long-term performance [8,9,10]. Several bioreactor configurations have previously been used for the treatment of H2S-contaminated airstreams, including biofilters, bioscrubbers and biotrickling filters.…”