METHOD OF TREATING WASTE WATER Russian patent published in 2013 - IPC C02F1/28 B01J20/08 

FIELD: chemistry.

SUBSTANCE: invention relates to purification of waste water from dissolved impurities and can be used particularly in food and chemical industry to treat waste water from factories. The method involves feeding a powdered sorbent in form of fine aluminium-containing powder obtained from aluminium-containing material which is a waste from aluminium strip etching when producing aluminium structures, by treating aluminium-containing material with 3-7% sodium hydroxide solution at temperature of 72°C-80°C with weight ratio of the aluminium-containing material to the sodium hydroxide solution ranging from 1:2 to 1:3 for 3-5 hours, filtering to obtain an aluminium hydroxide residue and a filtrate which contains sodium aluminate, mixing the filtrate with 1-2 M sulphuric acid solution to achieve pH of 6.4-7.4, filtering to obtain aluminium hydroxide residue, washing off sodium ions from the obtained residue with water, drying said residue in a drying cabinet at temperature of 180-200°C at heating rate of 10-20°C/h, calcining in a muffle furnace for 5-5.5 hours at 450-475°C at heating rate of 50°C/h, treating the obtained powdered aluminium oxide with an aqueous solution of surfactant OP-10 with concentration of 0.019-0.022% at temperature of 39-41°C, with ratio of aluminium oxide to the surfactant solution of 1:10 for 10-12 minutes and drying at room temperature. The obtained fine aluminium-containing powder is fed into the waste water in amount of 1.7-4 mg/dm³ waste water, followed by settling for 20-25 minutes and separation of the purified water.

EFFECT: invention improves efficiency of treating waste water while reducing the amount of sorbent used.

2 cl, 1 tbl, 3 ex