Pilot scale investigation of zinc and sulphate removal from industrial discharges by biological sulphate reduction with molasses as electron donor.

A biological sulphate reduction process, with molasses as an electron donor, was used for the removal of zinc and sulphate from Rayon industrial wastewater. The process involved reduction of sulphate to sulphide under anaerobic conditions. The sulphide-rich effluent was used to remove zinc as zinc sulphide precipitate.

Electron donors for biological sulfate reduction.

Biological sulfate reduction is widely used for treating sulfate-containing wastewaters from industries such as mining, tannery, pulp and paper, and textiles. In biological reduction, sulfate is converted to hydrogen sulfide as the end product. The process is, therefore, ideally suited for treating metal-containing wastewater from which heavy metals are simultaneously removed through the formation of metal sulfides.

Lead removal through biological sulfate reduction process.

The feasibility of lead removal through biological sulfate reduction process with ethanol as electron donor was investigated. Sulfide-rich effluent from biological process was used to remove lead as lead sulfide precipitate. The experiments were divided into two stages; Stage I startup and operation of sulfidogenic process in a UASB reactor and Stage II lead sulfide precipitation.