Waste water of Hanoi milk company was treated by oxidation method using CaOCl2 and Cao. The optimum conditions involving: pH, time and weight of CaOCl2 and CaO were studied. The obtained results were applied for the removal s2', organic compounds, smell and color in the milk waste water. The treated water is colorless and ordorless, s2" was completely removed, COD was reduced frorm 2120mg/l to 64 mg/1, which meet the requyrements of the waste water discharge standard.
