METHOD FOR REMOVING TOTAL ORGANIC HALOGEN COMPOUND IN CHLORINE-TREATED WASTE WATER OF KRAFT PULP BLEACHING STAGE

摘要

PURPOSE:To inexpensively and extremely efficiently remove the total org. halogen compd. in waste water by bringing the chlorine-treated waste water in a kraft pulp bleaching stage and iron scrap into contact with each other to dissolve ions and adding an alkali to alkalize the pH of this waste water to =8.0. CONSTITUTION:The chlorine treated waste water of the kraft pulp bleaching stage and the iron scrap are brought into contact with each other to dissolve the iron ions and the alkali is added to this waste water to adjust its pH to =8.0, by which the total org. halogen compd. in the chlorine-treated waste water of the kraft pulp bleaching stage is removed. In addition to the chlorine- treated waste water, hypochloride-treated waste water and chlorine dioxide- treated waste water may be contained in the kind of waste water to be applied. Lathing scrap, such as turnings, is utilizable as the iron scrap. The utlization of the chlorine-treated waste water of the kraft pulp bleaching stage as an alkaline source is possible and the use of slaked lime, calcium carbonate, sodium carbonate, caustic soda, etc., is possible.