Hydrogen sulfide removal using granular activated carbon biofiltration inoculated with Alcaligenes faecalis T307 isolated from concentrated latex wastewater.

Abstract A novel biofiltration of pure culture was developed for H 2 S removal from synthetic biogas using Alcaligenes faecalis T307 immobilized on granular activated carbon (GAC) as packing materials. The effect of operating parameters, including inlet H 2 S concentration, H 2 S flow rate, air flow rate, and height of media on the removal efficiency, was evaluated, together with a product analysis during long-term operation. Besides, the kinetics analysis of biofiltration was also studied. The experiment was performed in three biofilters. Biofilters A and B were packed with 20 and 40 cm of A. faecalis T307 immobilized GAC, respectively. Biofilter C as a control set was packed with 40 cm of the GAC without cell immobilization. The result showed that H 2 S removal efficiency of biofilters with A. faecalis T307 immobilized GAC was higher than 95% at high inlet concentrations (200–4000 ppm). Moreover, the complete H 2 S removal (100%) was found in biofilters A and B at H 2 S and air flow rate of 35 and 5.86 l h −1 , respectively. Product analysis of biofilters with A. faecalis T307 immobilized GAC was performed during the long-term operation (60 days). It was found that the major product was elemental sulfur and there was only a little of sulfate ions formed. In addition, the height of media did not significantly affect the H 2 S removal efficiency when the oxygen was sufficient at air flow rate of 5.8 l h −1 . Furthermore, in kinetic analysis, the maximum removal rate and saturation constant of H 2 S were calculated to be V m  = 1.1 kg m −3  s −1 and K s  = 5.2 g m −3 , respectively.