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

Abstract

The invention discloses a decoloring and nitrogen recycling synchronous method for high-concentration printing waste liquid, characterized by comprising the following steps: adding cationic exchange resin into certain high-concentration printing waste liquid, and stirring until the waste liquid reacts into pasty sludge; using treated waste water as dissolved air water to treat the pasty sludge by air flotation treatment so that sludge completely floats up; removing the floating sludge layer, and press-filtering and dewatering in a mechanical manner; discharging the cationic exchange resin settling to the bottom; filtering and dewatering the discharged cationic exchange resin, treating with an acid solution, recycling nitrogen, and regenerating the resin; adding the regenerated cationic exchange resin into high-centration waste liquid for cyclic use.The treatment method of the invention has printing waste liquid decoloring rate up to higher than 99.5%, ammonia and nitrogen removal rate up to higher than 90% and CODCr removal rate up to higher than 90%, provides synchronization of decoloring and nitrogen recycling for the waste liquid, causes no increase in the content of acid group ions in the waste water and also provides effective solid-liquid separation.

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, it is necessary to clean the printing equipment and water-based ink storage tanks,...

AI Technical Summary

Problems solved by technology

However, the coagulation method and acid precipitation 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, and 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