BigPatents India

A process for the treatment of an effluent stream containing water and an organic acid species which is a stronger acid than carbonic acid, comprising: adjusting the pH by adding an alkaline medium to the effluent stream; subjecting the effluent stream to oxidation treatment to convert the organic acid species to carbon dioxide, water and carbonate and/or bicarbonate ions; separating the oxidised effluent stream into a concentrated aqueous stream rich in (bi)carbonate ions and cationic species derived from said alkaline medium and a depleted aqueous stream which is substantially free of said (bi)carbonate ions and said cationic species; said separation is effected by contacting the oxidised stream with one reverse osmosis membrane. After adjustment to pH 7-8 the concentrated or depleted effluent stream are subjected to biological digestion and evaporation technique; recycling the concentrated stream for direct or indirect use as said alkaline medium; optionally following pH adjustment subjecting said effluent stream in treated or untreated form to an organics digestion process to produce a reduced COD aqueous stream containing suspended solids and dissolved species including (bi)carbonate ions and cationic species derived from said alkaline medium. No. of Pages : 25 No. of Claims : 14