Water-based inks comply with environmental protection requirements. The products are non-toxic, non-corrosive, odorless, non-flammable, non-explosive, and have good safety. They are easy to transport, have high concentration, require small dosages, have low viscosity, good printability, stable performance, good adhesion, fast drying, and excellent water resistance, alkali resistance, and abrasion resistance after drying. They are easy to adjust before, during, and after printing, resulting in printed products with full, vibrant colors, high gloss, and a luxurious appearance. Complex patterns can also achieve rich tonal variations, producing vivid and high-gloss colors. However, water-based ink production wastewater is a weakly alkaline, high-concentration, high-chroma, and difficult-to-biodegrade industrial wastewater, making wastewater treatment challenging.
1) The main pollutants in water-based ink production wastewater are water-soluble acrylic resins (color carriers), cyclic organic compounds containing chromophores (pigments), and high-molecular-weight alcohol or phenyl dispersants. Acrylic resin is the main component of CODcr in the wastewater, accounting for over 80%.
2) Pigments come in a wide variety of types. Inorganic pigments are mainly classified into three categories: salts, oxides, and carbonaceous pigments. Organic pigments include azo pigments, phthalocyanine pigments, nitro pigments, lake pigments, vat pigments, nitroso pigments, heterocyclic pigments, and many others.
3) In addition, they contain more than ten kinds of additives such as stabilizers, defoamers, retardants, surfactants, and preservatives.
