Textile printing and dyeing wastewater can save 20% of the national residential water if it is recyc
& ldquo: There will always be one less dress in your wardrobe. & rdquo; It doesn't seem like a joke. With the gradual improvement of living standards, shopping has become a common thing in our life. Especially women, buying clothes has become a big hobby. As long as they have time and financial ability, they will go shopping together in groups.
But when you marvel at colorful clothes in the mall, you know that behind it is huge pollution emissions. Taking printing and dyeing as an example, it is known that a ton of traditional dyes can produce more than 15 tons of wastewater. If there is pollution in other situations, it will be more. Printing and dyeing industry is absolutely in the textile industry & ldquo; big emitters & rdquo; dyeing wastewater discharge alone is as high as 3 million to 4 million cubic meters per day. If all the wastewater is recycled, it will save 20% of the average daily domestic water consumption of the whole country.
Recently, a survey report entitled "Pollution shouldn't become a new label of textile printing and dyeing industry" released by Green Jiangnan found that textile printing and dyeing enterprises have large sewage discharge, low waste water reuse rate, difficult to treat, and there are regional agglomeration phenomena, mainly in Jiangsu and Zhejiang provinces. At the same time, in Jiangsu and Zhejiang provinces where textile printing and dyeing enterprises have high regional concentration, the reporting rate is lower than the average, and there are many textile printing and dyeing enterprises secretly discharging pollutants and evading supervision.
High regional concentration is the remarkable characteristic of dyeing and printing industry < br />.
& High regional concentration is a prominent feature of the printing and dyeing industry. & According to Fan Yanting, a member of the Research Report compiler, & ldquo; China's printing and dyeing enterprises mainly distribute in South and East China. Zhejiang, Jiangsu, Shandong, Guangdong and Fujian are the five main production areas of printing and dyeing in China. These areas are rich in water resources and well-developed industrial chains of upstream and downstream. & From the development and scale of textile printing and dyeing enterprises, Jiangsu and Zhejiang are more prominent. Taking Wujiang in Jiangsu Province as an example, textile industry is not only Wujiang's traditional dominant industry, but also an important pillar industry, which has reached 100 billion energy levels.
Textile printing and dyeing industry is the earliest and internationally competitive traditional industry in China, but it is also a typical industry with high energy consumption and water consumption. The energy consumption of textile printing and dyeing industry accounts for 4.4% of the total national industry, and the water consumption accounts for 8.5%. Traditional textile printing and dyeing production not only pollutes the environment, but also produces various harmful chemicals, which do harm to our health.
& The main pollutants produced by textile printing and dyeing enterprises are industrial wastewater and industrial exhaust gas. & Fan Yanting explained that textile printing and dyeing wastewater is one of the industrial wastewater which is difficult to treat because of its large amount of water, high content of organic pollutants, great changes in water quality and low reuse rate of wastewater. At the same time, printing and dyeing wastewater contains a large number of organic pollutants, which can easily consume dissolved oxygen when it enters the water body, thus destroying the water ecological balance, and the wastewater flowing into the field will make the land salinized and alkaline. Chromium, lead, mercury and other heavy metal salts in wastewater are difficult to degrade by general biochemical methods.
The representative pollutants produced by textile printing and dyeing industry exhaust gas are soot, sulfur dioxide, nitrogen oxides and VOCs (volatile organic compounds). In this regard, Fan Yanting explained, & ldquo; spinning process will release harmful gases such as hydrogen sulfide, carbon disulfide and sulfur dioxide. In typical dyeing and finishing processes, fumes, particulate matter and VOCs are produced at the nodes of weaving, dry cloth, printing drying, steaming and final product shaping. & rdquo; VOCs emissions of textile printing and dyeing industry in China account for 8% of total VOCs emissions from different sources8%, accounting for more than 30% of VOCs emissions in industrial processes. Lack of textile printing and dyeing industry regulations
It is undeniable that in the absence of textile printing and dyeing industry regulations, both water pollution and air pollution are becoming increasingly serious.
The water use efficiency of textile printing and dyeing industry in China is low. The water consumption per unit is 3-4 times that of foreign countries, while the average content of pollutants in wastewater is 2-3 times that of foreign countries. As early as 1992, China promulgated and implemented the Water Pollutant Discharge Standard for Textile Dyeing and Finishing Industry, strictly controlling the discharge of textile printing and dyeing industrial wastewater. In 2012, the former Ministry of Environmental Protection completed the first revision of the standard, the revised standard is more stringent than before, and some new pollutant emission limits were added. However, according to Li Jia, the compiler of the research report, & ldquo; the whole regulatory system does not cover the pollution of toxic and harmful substances, some of which, even at very low concentrations, will endanger aquatic ecosystems and human health. & rdquo;
Wastewater from textile printing and dyeing enterprises is generally discharged through centralized treatment of sewage treatment plants, but when the treatment capacity of sewage treatment plants is limited, it becomes centralized-ldquo; pollution source-rdquo;. Green Jiangnan and other seven environmental protection organizations published the "Green Selection Textile Industry Phase 3 Report: New Standard Tests Brand Responsibility" which recorded that several years ago, Xiaoshan Linjiang Sewage Treatment Plant discharged directly to the Qiantang River beyond the standard. The water discharged from the site was loud, the water body was black and red, and the odor of sewage was pungent. There are many textile printing and dyeing enterprises in Xiaoshan Linjiang Industrial Park, which is adjacent to the sewage treatment plant, including some suppliers of international clothing brands.
& At present, it is generally acknowledged that printing and dyeing exhaust emissions mainly come from high-temperature stereotyping machine. The energy utilization rate of domestic high-temperature stereotyping machine is about 40%-50%, which is far below the advanced level of 70% abroad, and there is a large space for pollution reduction. & Relative to the particularity of textile printing and dyeing industry, the existing comprehensive emission standards of atmospheric pollutants and odor pollutants are limited, which can not fully cover the types of textile exhaust pollutants, and the national emission standards of atmospheric pollutants in textile printing and dyeing industry have not yet been promulgated.
In recent years, the central and local governments have promulgated a series of policies and regulations to restrict pollution conditions and regulate green production, aiming at the traditional high-polluting industries, including printing and dyeing. In June 2017, "Discharge Standards for Water Pollutants in Textile Dyeing and Finishing Industry" was evaluated and accepted. In October 2018, a seminar on the formulation of emission standards for atmospheric pollutants in textile printing and dyeing industry was held. Enterprises have also begun to explore ways to improve the efficiency of energy and equipment utilization, using clean production technology, investment in wastewater reuse projects.
Textile printing and dyeing exhaust emissions are more concealed and difficult to regulate than wastewater emissions < br />.
With the continuous improvement of information disclosure, the public is increasingly involved in environmental protection activities, providing strong support for environmental information disclosure from the source.
According to the survey report, according to the number of public reports, textile printing and dyeing enterprises are mostly reported in Jiangsu and Zhejiang provinces, which coincides with the characteristics of high regional concentration of China's textile printing and dyeing industry. From the point of view of the response rate, the average value is over 80%. In areas with fewer reports exceeding the standard, such as Fujian, Jiangxi, Hebei, Hubei and Shanxi, the response rate is 100%. However, the response rates of Jiangsu and Zhejiang are only 44% and 66%, respectively.
From Li Jia's point of view, this shows that in the areas where textile printing and dyeing enterprises gather, it is still an arduous task to rectify the environmental protection of textile printing and dyeing industry. While setting up special actions, we should constantly increase the frequency of law enforcement, severely crack down on illegal acts such as evasion of drainage, evasion of supervision and serious exceeding of standards, so as to form a high-pressure situation.
At the same time, the report also found that in textile printing and dyeing industry, 97% of the total reported cases were due to excessive wastewater, while only 3% were due to exhaust gas. In fact, textile printing and dyeing exhaust emissions are more concealed and difficult to regulate than wastewater emissions.
According to Li Jia, & ldquo; there are two reasons for the huge gap between wastewater and waste gas reporting. One is that there are few pollution factors (usually only smoke and dust, sulfur dioxide and nitrogen oxides) on the monitoring platform. The other is that the existing comprehensive emission standards for atmospheric pollutants and odorous pollutants are limited and can not fully cover textile wastes. The types of air pollutants and the imperfection of relevant standards have brought resistance to public supervision. & rdquo;
In order to reduce pollution, a new mode of cooperation between NGOs and environmental protection departments, enterprises and the public should be developed. In this regard, relevant suggestions are also put forward in the survey report.
For the environmental protection department, it is suggested to strengthen the construction of self-monitoring information release platform for key monitoring enterprises, increase the channels to solve environmental problems, improve the level of classification guidance and service, and strengthen the management of green supply chain.
For textile printing and dyeing enterprises, it is suggested to improve the quality of pollution source monitoring, strengthen the internal management of enterprises, actively promote the technological transformation of enterprises, explore innovative development mode, and build supply chain cooperation mechanism.
