The pollutants in printing and dyeing wastewater are mainly dirt on textile fibers such as cotton wool, salts, oils and lipids, as well as various pastes, dyes, surfactants, additives, alkalis, etc. added during processing.The contaminated water of printing and dyeing needs to be treated, and the use of polyacrylamide in the treatment has good effect and is safe.

1) Adopt advanced and targeted treatment processes, such as catalytic microelectrolytic technology, ozone-activated carbon technology, and pure oxygen aeration technology, to save land and reduce energy consumption.;

2) Classification, collection, qualitative treatment, and targeted pretreatment of individual wastewater to ensure stable compliance;

3) The reuse technology adopts ultrafiltration, reverse osmosis, etc. to ensure that the reuse water quality meets the production requirements.;

4) Develop new processes for concentrated water, such as ozone-biochar, aeration biological filters, etc., to ensure that concentrated water is stable and up to standard.;

5) Implement clean production, reduce the use of aniline dyes, and adjust the product use structure; adopt targeted technologies for aniline wastewater.A chemical and physical treatment method that uses the addition of flocculants and coagulants to precipitate or air float in a specific structure to remove pollutants from sewage.In the physical and chemical process, we generally select anionic flocculants or nonionic flocculants.

Characteristics and classification of printing and dyeing wastewater

Most of the pollutants in printing and dyeing wastewater are organic matter, and vary depending on the type of fiber used and the processing technology.Under normal circumstances, the pH value of printing and dyeing wastewater is 6-13, and the chromaticity can be as high as 1000 times. COD is 400-4000 mg/L, and BOD5 is 100-1000 mg/L. Printing and dyeing wastewater generally has a high concentration of pollutants, many types, toxic ingredients and high chromaticity.

From a technical point of view, printing and dyeing wastewater is a very complex category of wastewater.There are four characteristics: first, the composition of pollutants is very different, and it is difficult to classify and find common ground; second, the main pollution index COD is high, the ratio of BOD and COD is generally about 0.25, and the biochemical properties are poor; third, the chromaticity is high, and the dye molecules and ionic particles in the mixed water vary in size and weight, making it more difficult to decolorize; fourth, there are many types of wastewater discharged from various printing and dyeing processes, such as desulphurizing wastewater, cooking wastewater, bleaching wastewater, mercerizing wastewater, dyeing wastewater, printing wastewater, finishing wastewater, alkali reduction wastewater, etc., which are characterized by large water volume and differences in water quality characteristics. Larger.