METHOD OF BIOCHEMICALLY REMOVING ORGANIC SUBSTANCES FROM WASTE WATERS Russian patent published in 1999 - IPC

FIELD: waste water treatment. SUBSTANCE: purification is carried out on activated sludge in presence of 4:1 binary mixture of phthaloyl-gelatin and a high-molecular compound - water-soluble cationic polyelectrolyte, analogous 3:1 mixture being also added after biological purification is completed. 4: 1 mixture is added in amount 100-700 ppm (based on waste water weight) to waste water before air tank and 3:1 mixture is added in amount 500-1500 ppm in the secondary sludge sedimentation stage. Process allows increasing purification efficiency with regard to a series of most important industrial drainage impurities: surfactants by 30-35%, phenols by 18-20%, suspended and colloidal substances by 6-10%. Pretreatment of sludge with multicomplex reagent reduces sludge index by 46% instead of 8 and 21% obtained when using separately phthaloyl- gelatin and cationic polyelectrolyte, respectively. EFFECT: enhanced purification efficiency. 3 tbl