PULP AND PAPER PRODUCTION BLEACHING WASTE WATERS DECONTAMINATION METHOD Russian patent published in 1995 - IPC

FIELD: pulp and paper industry. SUBSTANCE: chlorine-organic composition bearing waste waters are treated by organic or nonorganic coagulation agent to form precipitation. Precipitation, that has combination of chlorine and coagulation agent derivatives, is subjected to action of polysulfide of alkaline metal. Polysulfide of alkaline metal, in particular sodium polysulfide is produced, using sulfur gas or element structure. Sulfur is also produced by catalytic oxidation of caustics, produced in process of pulp and paper boiling by sulfate method or caustics, produced after dissolving of refractory residue of sulfide lignin. Sulfur consumption is 1 3 mass to lignin 1 mass As a result of realization of the method degree of organic chlorine transformation in ionic chlorine is 98 -100 Produced suspension is suspended matter of sulfidized lignin combination with coagulating agent that has 5 0 of chlorine and water phase, that has salt waste, in which main share of chlorine is transformed. EFFECT: method increases degree of decontamination. 5 cl 1 tbl