SULFATE REMOVAL BY DESULFOVIBRIO VULGARIS IN ANAEROBIC BATCH REACTORS UNDER DIFFERENT PH CONDITIONS

The purpose of the present study was evaluate the metabolic routes involved in sulfate removal by Desulfovibrio vulgaris in batch reactors in mesophilic condition. The sulfate removal was evaluated at pH 4, 5, 6 and 7 using two carbon sources (formate and lactate). In the formate assay sulfate removal efficiencies of 6.3%, 8.4%, 16.7% and 50% were observed for pH 4, 5, 6 and 7, respectively, after 22 days of incubation. For lactate condition, better sulfate removal efficiencies were observed, 16.7%, 33.3%, 50% and 66.7% for pH 4, 5, 6 and 7, respectively, after 16 days of incubation. For both tested substrates, the best condition was in ph7. The sulfide production corresponded to the sulfate removal in both assays. With this, it can be concluded that the strain employed has the potential to remove sulfate using formate and lactate mainly under neutral conditions.