METHOD PURIFYING WASTE WATER FROM LEATHER PRODUCTION Russian patent published in 2014 - IPC C02F9/08 C02F1/24 C02F1/52 C02F1/56 C02F1/36 C02F103/24 

FIELD: chemistry.

SUBSTANCE: method includes homogenising waste water, mixing with a solution of an aluminium-containing coagulant, correcting pH, pressure floatation while saturating the waste water with air and removing floatation sludge. Correction of pH is carried out while homogenising the waste water to a value not lower than 10.5 by adding a 4% suspension of slaked lime in the presence of ethanolamine borate in amount of 4.0-6.0 mg/l. The aluminium-containing coagulant used is 10% aqueous aluminium chlorohydrate in amount of 10.0-20.0 mg/l. Before pressure floatation, 0.2% aqueous flocculant solution and ethanolamine borate are added to the mixture in amount of 15.0-25.0 and 3.0-5.0 mg/l, respectively. Saturation of the waste water with air during floatation is carried out by forced supply under a pressure of 0.11-0.25 MPa purified recycled effluent after treatment thereof with an ultrasonic field with frequency of 25-35 KHz with simultaneous supply of compressed air.

EFFECT: invention simplifies the purification process, reduces purification time and broadens technological capabilities of the method.

6 cl, 1 tbl