METHOD OF PURIFYING WASTE WATER FROM HEAVY METAL IONS Russian patent published in 2013 - IPC C02F1/62 C02F1/28 B01J20/24 C02F101/20 

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical, metallurgical and petrochemical industry when purifying waste water from heavy metal ions. The method involves step-by-step treatment of water with sodium hydroxide and sodium carbonate to form at each step treatment products in form of particles of partially soluble or insoluble metal compounds, strongly sorbed on sorbent-flotation agent particles, removing products at each step by pressure flotation to obtain floatation sludge. The sorbent-floatation agent used is fibrillated cellulose fibres which contain, with respect to weight thereof, at least 94% fibres with length of not more than 1.23 mm and at least 54% fibres with length of not more than 0.6 mm with water retention of the fibres of not more than 4 ml/g. The fibres are fed into the treated water in amount of 100 pts.wt per 100-1200 pts.wt insoluble metal compounds. In the preferred version, several reagents are further contain sodium phosphate; water is treated in three or more steps and at the last step sodium phosphate is used as the reagent. The floatation sludge formed is processed.

EFFECT: method simplifies the process, enables continuous purification of waste water with any concentration of metal ions with full removal thereof, and also enables to process and recycle sludge containing particles of metal compounds.

3 cl, 1 dwg, 4 ex