METHOD FOR SEWAGE TREATMENT Russian patent published in 2004 - IPC

FIELD: treatment of sewage.

SUBSTANCE: invention relates to methods fro treatment of sewage from toxic impurities - fluorine, copper, chrome, nickel. Method involves treatment of nitrate solutions with a mixture consisting of chloride, carbonate and calcium and potassium hydrate as limed pulp formed in process of treatment of sewage from zirconium manufacturing in the content of calcium 10-20 g/l and potassium 3-5 g/l in the solution in the presence of phosphorus compounds in the volume ratio of nitrate solutions and pulp 1 : 1, not less, and treatment is carried out up to pH value 7-10 at temperature 40-60 C for 0.5 h, not less. The content of inert salts KCl, NH₄NO₃, KNO₃, NaNO₃ and NaCl in pulp must be 13 g/l, not less. Washing out solutions containing trisodium phosphate in the concentration 1.0 g/l, not less, is used as phosphorus compounds. Method provides reducing consumption of lime, reducing toxic impurities in sewage and reducing sewage volume, elimination of improving land by silt deposition of well in pumping in sewage in underground galleries due to enhancing solubility of calcium sulfate in solution.

EFFECT: improved treatment method.

3 cl, 1 dwg, 1 tbl, 1 ex