Lab. samples of the liq. phase were treated at 23 degrees C with the mixt. of FeSO4 center dot 7H(2)O and 30% H2O2 soln. (Fe2+/H2O2 mass ratio 1:3 or 1:5) optionally after acidification with H2SO4 to pH 3.5 or 5. The Fe2+ content was 0.25-1.0 g/L. COD of the liq. phase was detd. by bichromate titration. The changes of color, turbidity and P content were detd. by spectrophotometric methods. The removal degree of org. impurities increased with increasing the conc. of Fe2+ and was efficient for the Fe2+/H2O2 mass ratio 1:3 at pH 3.5 or 5.0; and for Fe2+/H2O2 mass ratio 1:5 at pH 6.5. The highest redn. of COD, color, turbidity and P content was achieved at Fe2+ concn. 1.0 g/L, Fe2+/H2O2 mass ratio 1:3 and pH 6.5 by approx. 42, 87, 98 and 98%, resp.