The printing industry is an important part of the textile dyeing and finishing industry. The printing process will generate waste water, including soap washing and water washing wastewater after printing. The pollutant concentration is high. It contains dyes used in printing products such as pastes, dyes, and additives They are all different, resulting in significant differences in the composition of printing wastewater. Printing wastewater has high viscosity, high organic content, and is mostly aromatic hydrocarbons and heterocyclic compounds, which have colored groups (such as -N = N, -N = O) and polar groups (such as -S03Na, -OH,- NH2), and also mixed with phenols, anilines, bases and the like. Printing wastewater contains a large amount of pastes and coatings. Printing wastewater using starch pulp has good biochemical properties. Printing wastewater using chemical pulp has poor biochemical properties, especially printing wastewater containing chemical pulp-PVA is difficult to treat.
To implement the Law of the People's Republic of China on Environmental Protection, the Law of the People's Republic of China on Water Pollution Control, the Law of the People's Republic of China on Marine Environmental Protection, the Opinions of the State Council on Strengthening Key Environmental Protection Work, Develop the National Opinions on the Planning of Main Function Areas, protect the environment, prevent pollution, promote the progress of textile dyeing and finishing industrial production processes and pollution control technologies, and formulate printing wastewater discharge standards. This standard specifies water pollutant discharge limits, monitoring and monitoring requirements during the production process of textile dyeing and finishing industrial enterprises. From the date when the printing wastewater discharge standard was implemented, the "Water Pollutant Discharge Standard for Textile Dyeing and Finishing Industry" (GB 4287-1992) was abolished.
Discharge Standard for Water Pollutants in Textile Dyeing and Finishing Industry
In the standard, the state has made clear regulations for the requirements for printing wastewater discharge. From January 1, 2013 to December 31, 2014, existing enterprises have implemented the water pollutant discharge limits specified in Table 1.
Table 1 Concentration limits of pollutants discharged from printing wastewater of existing enterprises and baseline drainage per unit of product (unit: mg / l ph value, except for chromaticity)
4.2 As of January 1, 2015, existing enterprises implement the water pollutant discharge limits specified in Table 2.
4.3 As of January 1, 2013, new enterprises will implement the water pollutant discharge limits specified in Table 2.