METHOD OF EXTRACTION OF PHOSPHATE AND ORGANOPHOSPHATE FROM SEWAGE Russian patent published in 1995 - IPC

FIELD: sewage treatment. SUBSTANCE: sewage were treated with Al-containing coagulating agent and flocculant. Coagulating agent is alumina solution stabilized with alkali which is prepared by alkaline dissolving of bauxite and/or by alkaline etching of aluminium. Molar ratio of oxides Na₂O:Al₂O₃ in solution is 1.5-5.0. Solution has 100-300 g/l Al₂O₃ and 100-400 g/l Na₂O₃. Alumina solution is added to the sewage at concentration 10-200 mg/l. EFFECT: improved method of extraction. 10 cl