Photoautotrophic bacteria including of Chlorobium, Chromatium, Ectothiorhodospira, and Rhodobacter have been
used to convert H2S to elemental sulfur under anaerobic conditions. The major disadvantages of the practical use of photoautotrophic bacteria lie in their anaerobic nature and their need for radiant energy. As for the chemoorganoheterotrophic bacteria, Streptomyces sp., Pseudomonas aeruginosa, Bacillus brevis, Micrococcus sp., Xanthomonas sp., and Arthrobacter sp. have also been reported to oxidize H2S, but little information, such as desired
control mechanisms, proper design, and maintenance of the biofilter, is available. The tall biofilters are generally designed to treat dilute concentrations of H2S gas even though the problem of pressure loss arises.