METHOD OF REMOVING LEAD IONS FROM WASTE WATER Russian patent published in 2010 - IPC C02F1/62 C02F101/20 C02F103/16 

FIELD: chemistry.

SUBSTANCE: invention relates to purification of industrial waste water where waste water containing lead ions and waste water containing hexavalent chromium are formed. The invention can be used in machine-building, chemistry and other industries, where there is need for removing lead and chromium compounds from waste water. To realise the method, partially soluble compounds are deposited in waste water contaminated with lead compounds through dosed addition of solutions containing hexavalent chromium to the waste water. Solutions containing hexavalent chromium are obtained after separating the residue from spent concentrated chromium electrolytes or waste water from production of chrome plated objects or waste water from leather industry hardening agents, which are pretreated with a solution of hydroxides or carbonates of alkali metals to pH=7-8. The ratio of discharged waste water to solutions is controlled using a mass-spectrometric method, while determining concentration of lead and chromium compounds remaining in the purified water.

EFFECT: method provides high degree of purity of waste water and simultaneous production of valuable pigment.

2 ex