METHOD FOR TREATING REVERSE-OSMOSIS CONCENTRATED WATER OF PRINTING AND DYEING WASTEWATER AND RECYCLING REVERSE-OSMOSIS CONCENTRATED WATER FOR DYEING

摘要

A method for treating reverse-osmosis concentrated water of printing and dyeing wastewater and recycling the reverse-osmosis concentrated water for dyeing. The method comprises the following steps: treating the concentrated water obtained after the reverse-osmosis treatment of the printing and dyeing wastewater through coupling of high-temperature oxidation of sodium persulfate and the lime-soda process so as to obtain the treated concentrated effluent water; and adding salt into the treated concentrated effluent water according to dyeing requirements and recycling for dyeing. The coupling of high-temperature oxidation of sodium persulfate and the lime-soda process comprises the steps of: adding sodium persulfate into the concentrated water and carrying out a high-temperature oxidation reaction of sodium persulfate; adding calcium hydroxide into the concentrated water after being subjected to the high-temperature oxidation reaction of sodium persulfate so that the pH value of the concentrated water is greater than 9.50; and adding sodium carbonate and carrying out a lime-soda process reaction.