Abstract
The effects of sulfite or sulfate on anaerobic digestion of excess activated sludge were investigated at 37°C. No inhibition effect was observed up to 4 mM when sulfite was added to the anaerobic digestion adding sulfite system. Biogas production, however, was inhibited by the accumulation of acetate when sulfite was added in the concentration of 8 mM. The optimum concentration of sulfite was 2 mM for the biogas production and 4 mM for the solubilization of VSS of the sludge. The activity of sulfate reducing bacteria was higher when sulfite was added than sulfate was used. In this study, it was confined that sulfite is effective for the solubilization of organic matter.
