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Light Of Textile | First Prize Of Textile Science And Technology Progress: "Turning Waste Into Treasure", Green Innovation Of Printing And Dyeing Wastewater Treatment

2024/12/25 19:36:00 38

　　 The 2024 Science and Technology Award of China Textile Industry Federation was announced recently. Professor Wang Haitao of Tianjin University of Technology, as the first person to complete the project, has joined forces with Zhejiang Jinma Environmental Technology Co., Ltd., Tianjin Membrane Technology Co., Ltd., Shanghai University of Engineering Technology, Shaoxing Haitong Printing and Dyeing Co., Ltd., Joyful Home Textile Co., Ltd., Shengzhou Youngor Wool Textile Co., Ltd., Alar Xingmeida Printing and Dyeing Co., Ltd The project of "Key Technology and Application of Membrane Water Treatment and Liquid Sodium Sulfate Reuse in Printing and Dyeing Industry" jointly completed by Quanzhou Haitian Dyeing and Finishing Co., Ltd. won the first prize of Science and Technology Progress Award of China Textile Industry Federation.

　　 The problem of difficult treatment of printing and dyeing wastewater has always been a "barrier" to the sustainable development of the textile industry. Its annual discharge amounts to 1.8~2 billion tons, accounting for about 11% of the national wastewater discharge. It is a highly difficult organic industrial wastewater. In view of the poor performance of ultrafiltration membrane, rapid decline of reverse osmosis membrane performance, and difficulty in recycling sodium sulfate in traditional treatment technologies, the project research team has climbed the technical peak and made a major breakthrough. It has developed a high-strength fiber fabric reinforced hollow fiber ultrafiltration membrane technology, greatly improving the anti pollution and mechanical performance of the membrane, and effectively purifying textile printing and dyeing wastewater; A highly stable and pollution resistant reverse osmosis membrane suitable for the reuse of printing and dyeing wastewater has been developed to ensure efficient and stable treatment effect; The developed multi-stage membrane integration technology for liquid sodium sulfate recycling realizes efficient recovery of sodium sulfate and reduces enterprise costs. Innovative technology has enabled the recycling rate of printing and dyeing wastewater to exceed 65%, and the recycling rate of sodium sulfate to reach more than 75%, which has promoted the technological progress of printing and dyeing wastewater treatment, improved the recycling rate of water resources, reduced wastewater discharge, and assisted the high-quality development of the textile printing and dyeing industry.

　　 New Technology for Preparation of "Fiber Armor" Ultrafiltration Membrane

　　 The project focuses on the weak link of ultrafiltration membrane performance of printing and dyeing wastewater, and innovatively adopts the strategy of "fiber armor", that is, fiber fabric reinforcement composite one-step membrane manufacturing, membrane performance regulation and post-treatment technology. Using three-dimensional knitting, knitting improvement, hybrid fiber knitting and online shaping technology to create high-strength fiber reinforcement, combined with the one-step process of composite membrane making, a new type of fabric fiber reinforced PVDF hollow fiber membrane was successfully developed. The breaking tensile strength of the membrane can reach more than 300 N, the pure water flux range is 2000~4000 L/(㎡・ h), and the service life is more than 5 years. Compared with the conventional reinforced membrane, its advantages lie in: first, the original weaving method, which makes it difficult to peel the fiber fabric from the membrane; Second, it has an ultra-thin separation layer, only 15 microns, which greatly improves the flux; The third is one-step molding and convenient industrialization.

　　 The performance of "intelligent barrier" reverse osmosis membrane has jumped

　　 The project team made in-depth research on the performance degradation of reverse osmosis membrane after frequent cleaning in the field of reclaimed water reuse in the printing and dyeing industry. Starting from the preparation regulation of support layer and separation layer, the highly stable uniform pore size polysulfone support membrane was prepared by NIPS method, coupled with predetermined amount coating, secondary interfacial polymerization and surface functionalized graft modification, the average membrane flux of the prepared reverse osmosis membrane was ≥ 45 L/(m2 · h), the desalination rate of NaCl remained above 97% within three years, and the membrane pollution rate was reduced by more than 20% compared with the traditional membrane, The water reuse rate of the system has reached more than 65%, significantly improving the stability and anti pollution ability of the reverse osmosis membrane, providing a reliable guarantee for the deep reuse of printing and dyeing wastewater, promoting the progress of the water reuse technology in the printing and dyeing industry, and leading the new direction of the advanced treatment technology of printing and dyeing wastewater.

　　 Multilevel membrane integration process of "Glauber's salt circulating magic cube"

　　 In order to overcome the difficulty of inorganic salt resource utilization of high salt printing and dyeing wastewater, the project team ingeniously designed the multi-level membrane integration process of "Glauber's Cube". The multi-stage membrane integration technology for liquid sodium sulfate recycling was developed, and the process route of "anti pollution ultrafiltration membrane+special roll ultrafiltration membrane+ozone oxidation+reverse osmosis+dealkalization" was adopted, realizing the innovation of the whole process from pretreatment to advanced treatment and then to resource recovery. The conductivity of the liquid sodium sulfate concentrate recovered by this technology is ≥ 70000 μ S/cm, the chroma is ≤ 50, and the system salt recycling rate is more than 75%, which significantly reduces the cost of enterprises, reduces the pollution of high salt wastewater, and provides a new idea for the sustainable development of the printing and dyeing industry.

　　 The achievements of the project have been widely applied in the field of textile printing and dyeing, and have achieved remarkable results. The project team popularized the technology to more than 100 printing and dyeing enterprises, with application scale ranging from 2000 tons/day to 30000 tons/day, effectively solving the environmental problems of enterprises, helping enterprises to save water, reduce emissions and recover resources. "Scientific research helps textile printing and dyeing, and innovation drives green progress". This achievement has effectively improved the competitiveness of textile printing and dyeing enterprises, won high recognition in the market, and provided strong technical support for the high-quality development of the printing and dyeing industry.

(Source: Light of Textile)