Synchronous decolorization and nitrogen recovery method of high-concentration printing waste liquid

Abstract

The invention discloses a synchronous decoloring and nitrogen recovery method for high-concentration printing liquid waste. The method is characterized by comprising the following steps: adding cation exchange resin into the high-concentration printing liquid waste and stirring for a certain period of time; heating the mixed liquid waste to 45-55 DEG C and performing thermal insulation treatment; performing aeration for sludge floating; discharging the cation exchange resin precipitated at the bottom; continuing to heat the treated liquid waste to 75 DEG C and performing thermal insulation treatment for a certain period of time; taking out sludge and discharging wastewater after cooling; performing treatment with an acid solution after performing filtration and dehydration on the discharged cation exchange resin, recovering nitrogen, and meanwhile regenerating cation exchange resin; and then adding the regenerated cation exchange resin into untreated high-concentration printing liquid waste for recycling. By adoption of the method, the decoloring ratio of the printing liquid waste reaches up to 99.5% or above, the ammonium-nitrogen removal ratio reaches 85% or above, and the CODCr removal ratio reaches 90% or above, so as to achieve synchronous decoloring and nitrogen recovery of the liquid waste; and according to the method, not only is the content of acid radical ions in the wastewater not increased, but also a good effect of solid-liquid separation is achieved.

Description

technical field [0001] The invention belongs to the technical field of textile printing and dyeing industry, in particular to a method for synchronous decolorization and nitrogen recovery of high-concentration printing waste liquid. Background technique [0002] Ink is composed of pigments, binders, fillers, additives, etc., and can be divided into oil-based inks and water-based inks. Oil-based ink contains a large amount of organic solvents, causing serious pollution and will be gradually eliminated. Water-based ink is mainly composed of water-soluble resin, pigment, alcohol, amine or ammonia and other additives and water. Water-based ink is widely used in various fields because of its health, environmental protection and safety characteristics. At present, a large number of plastic packaging (waterproof) materials are increasingly using water-based inks when printing. When changing colors, printing equipment and water-based ink storage tanks need to be cleaned, resulting...

AI Technical Summary

Problems solved by technology

However, the solid content of the formed sludge is as high as 5-10%, which is difficult to dewater, and the coagulation method and acid analysis method can only remove water-soluble resins, pigments and other organic substances in the waste liquid, but cannot remove the ammonia nitrogen in the waste liquid at the same time , usually need to be removed by other chemical or biological methods

Especially the acid analysis method directly adds inorganic acid to the waste liquid, which increases the content of acid radical ions in the waste liquid, causes secondary pollution, and easily forms brackish water