China is the world’s largest producer of textiles, and the textile industry has historically been one of the worst polluters in terms of carbon emissions and water pollution.
China’s official data from the Ministry of Environmental Protection show that in 2015, the textile industry in China was the third largest source of wastewater and released 10.1% or 1.84 billion tons of wastewater effluent into the environment. China is nowadays moving away from a passive environmental policy that existed mostly in name prior to 2015, and is facing this issue with strict new environmental regulations. Textile companies who respond slowly or who do not take China’s new environmental policy seriously to become compliant quickly risk negative repercussions to their business and perhaps even the life of the business itself.
Textile manufacturing uses enormous quantities of potentially harmful chemicals. Large quantities of dyes, additives and stabilizers are used to treat textiles, which then enter the environment through wastewater. According to the Chinese Textile Industry Association, 25% of global chemical output is used in the textile industry.
In 2011 Greenpeace published “Dirty Laundry”, a report that showed that wastewater in textile industry zones in Guangdong and Zhejiang contained chemicals that cause cancer or are harmful to reproduction. After the report, some leading brands, including fast fashion companies Inditex (Zara’s owner) and H&M, along with Puma, Nike and Adidas, committed to ending the release of harmful substances from their supply chains by 2020. A Zero Discharge of Hazardous Chemicals Foundation (ZDHC) was set up to encourage and guide change in the sector.
An increasing awareness around the water pollution problem has led to rapid water treatment equipment development. The main product separation equipment, oxidation disinfection equipment and domestic treatment equipment have been able to meet the processing needs of general industrial wastewater and domestic sewage, and the processing capacity has been improved.
In recent years, the proportion of sewage discharged by the textile industry to the national industrial wastewater discharge is still large, which has attracted the attention of relevant departments. On September 26, 2019, the Ministry of Ecology and Environment issued the “Water Pollution Standards for Textile Industry” (Draft for Comment), which standardized and tightened the water pollutant discharge standards for garment enterprises. For example, the limits of chemical oxygen demand (COD) are stricter than the standard limits of similar industries in developed countries. After the implementation of the new standard, the adjustment of the baseline displacement and ammonia nitrogen and other pollutant indicators will bring about a significant reduction in the amount of sewage and ammonia nitrogen emissions. At present, wastewater treatment includes physical treatment, chemical treatment, biological treatment and other technologies. The industry believes that biological treatment should be given priority, while physical and chemical treatment could be used to complement the biological treatment. The addition of various new printing and dyeing methods further increases the difficulty in the treatment of printing and dyeing wastewater. Traditional treatment methods or separate technologies couldn’t ?meet the comprehensive management needs, so the synergy of various treatment technologies has become a primary method. For example, ozone oxidation combined with catalyst, ultrasonic, ultraviolet and micro-electrolysis can effectively improve the efficiency of ozone oxidation technology in the treatment of printing and dyeing wastewater. The data shows that the dyeing and finishing are the biggest sources of pollution in the textile industry, followed by desizing, refining, bleaching, mercerizing and printing. The textile printing and dyeing wastewater has a large amount of water, high content of organic pollutants, and large changes in water quality. It is a kind of sewage that is difficult to handle in industrial sewage.
In the future, the recycling of industrial wastewater will be an important step in the treatment of printing and dyeing wastewater. According to data analysis, the average daily discharge of dyed wastewater in China is as high as 3 million to 4 million cubic meters. If all these wastewaters are recycled, it will save 20% of the daily average domestic water consumption of the national residents.
China’s environmental policy has placed textiles in a list of industries that are required to develop “circular economies”. ?In this model, the industry focuses on reuse, remanufacture and on completely closing the loop so that little is lost in the way of resources. WieTec 2020 is a platform that gathers sewage treatment industry professionals from all around the globe, and a place that offers a perfect opportunity for them to exchange their ideas, and find a way to coordinate their thoughts and ideas with China’s latest environmental policies.? We hope that together we can find solution for this problem.