PROCESS FOR THE TREATMENT OF WATER CONTAINING HEAVY METAL IONS

摘要

A process is provided for the treatment of water containing heavy metal ions and sulfate, wherein metal ions are first precipitated as sulphides and separated, sulphate is then biologically reduced to sulphide, and sulphide is returned to the precipitation stage. Remaining sulphide may be oxidised to elemental sulphur and elemental sulphur separated to produce desulphurised waste water, or residual sulphide may be removed by addition of metal salts prior to precipitation.