METHOD OF PURIFYING INDUSTRIAL WASTE WATER Russian patent published in 2014 - IPC C02F9/08 C02F1/24 C02F1/52 C02F1/56 C02F1/36 C02F103/16 

FIELD: chemistry.

SUBSTANCE: method includes homogenising waste water, correcting pH to a value not lower than 10.5, mixing with aluminium sulphate solution and a flocculant solution with concentration of 0.1-0.2 wt %. The method includes pressure floatation by feeding into the waste water 40-60 m³/h of a purified recycled effluent at pressure of 0.11-0.25 MPa while simultaneously feeding compressed air and removing floatation sludge. Before feeding into the waste water, the purified recycled effluent is treated with an ultrasonic field with frequency of 25-35 kHz. Correction of pH is carried out by adding to the waste water a suspension of slaked lime or sodium hydroxide or sodium carbonate solution. Flocculant consumption is equal to 30-40 mg/l. The flocculant used is high-molecular weight cationic flocculants. Ultrasonic field treatment is carried out using a water-gas ejector with a jet-edge generator while feeding compressed air into the ejector at a pressure of 0.25-0.45 MPa.

EFFECT: simple purification process, reducing time for purification from ions of nonferrous and heavy metals, suspended substances, oils and fats to 16-20 min while maintaining given purification efficiency.

6 cl, 1 tbl, 5 ex