Anaerobic corrosion and bacterial sulfate reduction: Application for the purification of industrial wastewater

Experiments that form the basis for a biotechnology for removing sulfate with immobilized sulfate‐reducing bacteria from wastewaters polluted with sulfate, heavy metals, soluble forms of arsenic, and nitrates are described. The maximum rate of sulfate removal from wastewaters varied with the type of carrier used for cell immobilization. With the inert carrier dolomite, the maximum rate was 0.60 g m^‐2 day^‐1, whereas with the active carrier metallic iron, the rate was 3.45 g m^‐2 day^‐1. Sulfate removal from the wastewater resulted in simultaneous precipitation of heavy metals as sulfides. Furthermore, arsenic concentrations were lowered below 0.1 mg L^‐1, and almost 95% of nitrate was removed from the water.

Keywords:

• arsenic precipitation
• metal sulfide precipitation
• packed bed reactor
• sulfate reduction
• wastewater