METHOD OF TREATING WASTE WATER Russian patent published in 2013 - IPC C02F1/28 C02F1/52 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 adding iron chloride to the water to be treated. Further, fine aluminium-containing powder obtained from aluminium-containing material, which is a waste from aluminium strip etching when making aluminium structures, is added to the treated water. Preparation of said powder involves treating aluminium-containing material with 3-7% sodium hydroxide solution at temperature of 72-80°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 containing sodium aluminate, mixing the filtrate with 1-2 M sulphuric acid solution to achieve pH of 6.4-7.4, filtering to obtain an 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 a 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. Iron oxide is added to the waste water in form of 1% iron chloride solution in amount of 1-7% of the volume of waste water, and the obtained fine aluminium-containing powder is added to the waste water in amount of 1.7-4 mg/dm³ waste water, followed by settling for 20-25 minutes and separating the purified water.

EFFECT: invention increases efficiency of treating waste water while reducing sorbent consumption.

2 cl, 2 tbl, 3 ex