Printing and dyeing industry is an important industry in the textile industry, textile printing and dyeing industry, printing and dyeing wastewater discharge is one of the key industrial pollution sources.
Dyeing wastewater is a kind of organic waste water containing a certain amount of difficult biodegradable substances. The pollutant concentration (COD), deep color, low nitrogen and phosphorus content, is difficult to deal with one of the industrial wastewater.
In recent years, with the market demand for the diversification of printing and dyeing products, printing and dyeing products in small quantities, more varieties of products to increase production, production equipment, intermittent printing and dyeing equipment occupy a larger proportion. Due to the variety of products and the low level of automatic control of dyestuff and additives, the wastewater discharge and water quality are higher than those of the continuous dyeing process, which has increased the difficulty in the treatment of wastewater treatment project. The traditional pollution control standards discharge technology challenges.
Textile printing and dyeing industry over the years to actively promote cleaner production process, focusing on pre-treatment process and dyeing process. Such as: in the pre-treatment process on the use of high efficiency and shorten the process of booze bleaching process, biological enzyme pretreatment process, the environment-friendly pre-treatment auxiliaries and improved technology in the dyeing process using environmentally friendly low-alkali-fixing reactive dyes wet short- Dyeing, cold pad batch dyeing, supercritical CO, dyeing, micro-suspension dyeing, microcapsules without additives dyeing, digital inkjet printing and other new technologies are also in-depth research and different degrees of application; dyeing equipment, The use of a small bath than the liquid dyeing machine, air dyeing machine and frequency control transmission. The adoption of these technologies and equipment has a significant effect on energy saving and pollution reduction. At present, these technologies are being gradually extended and applied.
In recent years the development of polyester alkali reduction process, in the production process will produce high alkaline, high concentrations, containing refractory terephthalic acid and other organic pollutants in wastewater, printing and dyeing industry is difficult to deal with one of the wastewater . At present, some enterprises have adopted this method to recover terephthalic acid, but in the areas with high environmental quality, there are still some difficulty in treatment and higher disposal cost. If such wastewater is not treated will cause greater pollution of the environment.
From the domestic practical experience, enterprises in order to achieve good governance and save investment, we must first implement cleaner production, reduce the amount of pollutants generated and emissions, and finally, to reduce the amount of pollutants generated by waste water, And then the end of governance, which can reduce the management of investment.
In the end of treatment, the first should be pre-treatment, and then use the biological treatment mainly to the physical and chemical treatment, supplemented by the comprehensive treatment of technical lines, which is in line with the actual situation of printing and dyeing industry. Through biological treatment can remove a large number of organic pollutants in wastewater, the remaining pollutants can be reused, such as chemical dosing and other physical and chemical methods to further remove. The use of the technology on the color of the line also has a good removal effect.
Reference: 《China Environmental Protection Industry》