Biological deodorization of hydrogen sulfide using porous lava as a carrier of Thiobacillus thiooxidans

Biological deodorization of hydrogen sulfide (H2S) was studied using porous lava as a carrier of Thiobacillus thiooxidans in a laboratory-scale biofil ter. Three different samples of porous lava, A, B, and C, which were obtain ed from Cheju Island in Korea, were used. The water-holding capacities of s amples A, B and C were 0.38, 0.25, and 0.47 g-H2O/g-lava, respectively. The pHs and densities of the lava samples ranged from 8.25-9.24 and 920-1190 k g/m(3), respectively. The buffering capacities, expressed as the amount of sulfate added to lower the pH to 4, were 60 g-SO42-/kg-lava for sample A, 5 0 g-SO42-/kg-lava for B, and 90 g-SO42-/kg-lava for C. To investigate the r emoval characteristics of H2S by the lava biofilters, T. thiooxidans was im mobilized on the lava samples. Biofilters A and C showed a removal capacity of 428 g-S.m(-3).h(-1) when H2S was supplied with 428 g-S.m(-3).h(-1) of i nlet load at a space velocity (SV) of 300 h(-1). At the same inlet load and SV, the removal capacity of biofilter B was 396 g-S.m(-3).h(-1). The H2S c ritical loads of biofilters A, B and C at a SV of 400 h(-1) were 396, 157 a nd 342 g-S.m(-3).h(-1), respectively. It is suggested that natural, porous lava is a promising candidate as a carrier of microorganisms in biofiltrati on.