Carbon disulfide and hydrogen sulfide removal with a peat biofilter

Simultaneous removal of H2S and CS2 was studied with a heat biofilter inocu lated with a Thiobacillus strain that oxidizes both compounds in an acidic environment. Both sulfurous gases at concentrations below 600 mg S/m(3) wer e efficiently removed, and the removal efficiencies were similar, 99%, with an empty bed retention time (EBRT) of more than 60 sec. Concentrations gre ater than 1300-5000 mg S/m(3) caused overloading of the filter material, re sulting in high H2SO4 production, accumulation of elemental sulfur, and red uced removal efficiency. The highest sulfur removal rate achieved was 4500 g-S/day/m(3) filter material. These results indicate that peat is suitable as a biofilter material for the removal of a mixture of H2S and CS2 when co ncentrations of gases to be purified are low (less than 600 mg/m(3)), but i t is still odorous and toxic to the environment and humans.