METHOD OF TREATING WATER CONTAINING HEAVY METAL IONS Russian patent published in 2002 - IPC

FIELD: chemical industry, more particularly treatment of sewage containing heavy metal ions and sulfate ions. SUBSTANCE: metal ions are first deposited in the form of sulfides and separated. Sulfate is then biologically reduced to sulfide using hydrogen or carbon oxide as electronic donor, and sulfide is recycled to deposition stage. Residual sulfide is oxidized to elementary sulfur, and sulfur is separated to prepare desulfilized sewage. Residual sulfide is removed by addition of metal salts prior to deposition. EFFECT: selective deposition and reuse of heavy metals, reduced intoxication of sulfate-reducing bacteria. 9 cl, 4 dwg, 1 ex, 1 tbl