Removal of sulfide hydrogen and ammonia from waste gases by a biofilter

A laboratory-scale biofilter was used to investigate the potential of the biofilter for removal of sulfide hydrogen and ammonia from waste gases in this study. It took about 40 days for the biofilter to start up, and at the end of start-up period, a high removal efficiency of sulfide hydrogen and ammonia can be obtained. Under the steady state of the biofilter operation, removal efficiency of sulfide hydrogen and ammonia decreased with decrease in gas retention time (with the range of 20-60s), but the minimum removal efficiency attained was still above 82.4% for sulfide hydrogen and above 86.9% for ammonia. Microbial analysis demonstrated that non-acidophilic thiobacteria, ammonia oxidizing bacteria and nitrite oxidizing bacteria were dominant in the biofilter in stable operation. The biofiltration process had been proved to be efficient for co-treatment of sulfide hydrogen and ammonia.