METHOD OF TREATMENT OF SEWAGE WATERS CONTAINING THE PRODUCTS OF DECOMPOSITION OF LUBRICANTS-COOLANTS TO REMOVE OILS AND SUSPENDED MATTER Russian patent published in 1998 - IPC

FIELD: treatment of sewage waters; applicable in mechanical engineering and metal working industries. SUBSTANCE: method includes preliminary settling and two-stage coagulation with electrocoagulation at the second stage and settling after each stage. After preliminary settling and correction of pH, the first stage is carried out with coagulant-flocculant ratio of (4.5-6.0): (1.5-3.0) and their mixture with clarified water and velocity gradient of 150-200 ss^-1 for 1-3 min, and flocculation proper with velocity gradient of 30-50 ss^-1 for 20-60 min. After treatment, water contains ether-soluble oil in the amount of 25-80 mg/l and suspended matter in the amount of 10-20 mg/l. EFFECT: higher efficiency. 1 tbl