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Attention: This Cotton Printing And Dyeing Wastewater Treatment Technology Has Reached The International Advanced Level

2023/7/6 16:01:00 0

　　 On June 27, 2023, the China Textile Industry Federation organized and held a scientific and technological achievement appraisal meeting of the project "Key Technology and Application of Efficient and Cooperative Treatment of Multi pollutants in Cotton Printing and Dyeing Wastewater" jointly completed by Hebei Ningfang Group Co., Ltd., Donghua University and Hebei Hantang Hongyuan Environmental Protection Technology Co., Ltd. in Xingtai, Hebei Province. The appraisal committee agreed that the project achievements reached the international advanced level.

　　 The research results of the project are briefly introduced as follows:

　　 1、 Project research background

　　 Cotton fabric printing and dyeing wastewater contains polyvinyl alcohol (PVA), organic phosphorus, ammonia nitrogen and other pollutants in different processes, resulting in complex composition, high alkalinity and difficult treatment of cotton printing and dyeing wastewater, while the corresponding discharge requirements are constantly tightened. On the basis of the Discharge Standard of Water Pollutants for Textile Dyeing and Finishing Industry (GB4287-2012), local standards based on local environmental capacity requirements have been issued, such as the Discharge Limits of Main Water Pollutants for Urban Sewage Treatment Plants and Key Industrial Industries in the Taihu Lake Basin (DB32/1 072-2018), The drainage of enterprises is even required to meet the requirements of Class IV water in the Environmental Quality Standard for Surface Water (GB3838-2002). The traditional cotton printing and dyeing wastewater treatment method is difficult to meet the discharge standard of wastewater, and the wastewater treatment does not meet the standard, so the enterprise cannot carry out normal production activities.

　　 In order to ensure the stable treatment of cotton printing and dyeing wastewater, meet the requirements of low concentration discharge, and ensure the smooth production of enterprises, Hebei Ningfang Group Co., Ltd., Donghua University and Hebei Hantang Hongyuan Environmental Protection Technology Co., Ltd. jointly undertook the China Textile Union Science and Technology Guidance Project "Key Technologies and Applications for Efficient and Cooperative Treatment of Multi pollutants in Cotton Printing and Dyeing Wastewater (No. 2021145)".

　　 2、 Main innovation points of the project

　　 Through the research on new technology and process of cotton printing and dyeing wastewater treatment, the project optimizes and adjusts the operation process parameters to achieve efficient and collaborative treatment of multi pollutants in cotton printing and dyeing wastewater. The main innovations are as follows:

　　 1. For the PVA wastewater generated in the process of cotton printing, dyeing and desizing, the crosslinking modification of high concentration and high stability PVA is carried out by using the crosslinking property of free radicals to strengthen the sedimentation property and achieve efficient treatment of wastewater pretreatment.

　　 2. The multistage anaerobic aerobic advanced oxidation coupling process is used to realize the partition enrichment of different dominant microorganisms, improve the removal efficiency of aniline, oligomer and other refractory pollutants, reduce the inhibition of sulfide on biological bacteria by increasing the improvement of blowing process, and ensure the stability of low concentration wastewater discharge through the independently developed Fenton oxidation device, Combined with the return of excess sludge, sludge reduction can be realized synchronously.

　　 3. Optimize the sludge conditioning agent, use anionic polyacrylamide instead of cationic amide, significantly reduce the cost and extend the replacement time of filter cloth of the filter press, carry out mechanical transformation of the filter press, significantly improve the air tightness of the filter press, strengthen the sludge dewatering efficiency, so as to shorten the working cycle of sludge support and improve the dewatering rate of printing and dyeing sludge.

　　 3、 Project industrialization and application

　　 The project has built a large-scale operation system in Hebei Ningfang Group Co., Ltd., with a treatment capacity of 2720 m3/d. The enterprise will integrate the key technologies of this achievement on the basis of not destroying the original process layout, maintaining the floor area and treatment scale unchanged, and the effluent quality can stably reach the Class IV standard limit in Table 1 of the Environmental Quality Standards for Surface Water (GB 3838-2002), The moisture content of dewatered sludge is further reduced through efficient dewatering of printing and dyeing sludge and pressure filtration drying technology. From 2020 to 2022, the cumulative emission reduction of COD is 177.48 tons, ammonia nitrogen is 24.39 tons, water saving is 3494 tons, wet sludge is reduced by 3682 tons, and significant environmental benefits are achieved.

　　 4、 Brief introduction of project completion unit

　　 Hebei Ningfang Group Co., Ltd., founded in 1973, is a cross industry and diversified large-scale enterprise with textile, printing and dyeing, and clothing as the leading industries, integrating diversified operations. The enterprise is mainly engaged in the weaving, dyeing and garment processing of clothing and home textile fabrics. It has 500 shuttleless looms, 5 pad dyeing production lines and more than 50 garment production lines. It has entered the ranks of "National Top 100 Textile and Garment Enterprises Export" and "National Top 500 Textile and Garment Competitiveness" for many consecutive years. It has successively obtained the certification of quality management, environmental management, occupational health and safety management, energy management, intellectual property rights and other management systems. A total of 30 invention patents, 80 utility model patents, 12 design patents, 3 software copyrights were obtained, and 3 national standards, 12 industrial standards, and 6 group standards for the textile industry were formulated.

　　 Donghua University is a "double first-class" key construction university directly under the Ministry of Education. The discipline of environmental science and engineering was founded in 1976, which is one of the earliest environmental disciplines in China. With a complete talent training system, Donghua University has been selected as a key discipline in Shanghai, a first-class discipline in Shanghai universities, a class IV peak discipline in Shanghai universities, and a national dyeing and finishing engineering technology center National Environmental Protection Textile Industry Pollution Textile Engineering Technology Center, Key Laboratory of Textile Industry Pollution Treatment and Emission Reduction Technology and other scientific research platforms. Featured by textile pollution prevention, guided by solving environmental problems, it continuously provides a series of technologies, policies and standards for textile pollution prevention. The pollution prevention and control technology system oriented to the goal of reducing pollution and carbon has won the first and second prizes of the National Science and Technology Progress Award, the first prize of the Shanghai Science and Technology Progress Award, the first prize of the China Textile Industry Federation Science and Technology Progress Award, etc. The national ecological environment standards such as the Technical Specifications for Application and Issuance of Pollution Discharge Licenses, Textile Printing and Dyeing Industry, and the Guide to Feasible Technologies for Pollution Prevention and Control in Textile Industry, as well as the manual on production and pollution discharge coefficient of the second national pollution source survey of textile industry, textile clothing and apparel industry, which were led to develop, were obtained by national textile enterprises Widespread application and affirmation of textile industrial parks and consulting enterprises. In the past five years, it has undertaken more than 600 projects of all kinds, with a total funding of nearly 100 million yuan. It has published more than 1900 scientific research papers in various journals. High level papers have been listed in the top 1% of the ESI world. It has published more than 10 monographs. More than 60 independent intellectual property achievements have been applied to large-scale pollution prevention projects.

　　 Hebei Hantang Hongyuan Environmental Protection Technology Co., Ltd. is committed to the regeneration and recycling of waste SCR denitrification catalyst. The company has three production lines with an annual recycling capacity of 20000m3, which is the first enterprise in Hebei to obtain the qualification for regeneration of waste denitration catalyst. The company has established a close technical cooperation relationship with Zhejiang University all the year round, has a first-class team of R&D, management and technical service talents, and has established a research and development platform for enterprises in Hebei Province. With strong scientific research strength, the company has been selected as a state-level technology-based SME warehousing enterprise, a technology-based SMEs in Hebei Province, a high-tech enterprise in Hebei Province, and a specialized and special new enterprise in Hebei Province. The enterprise has 3 invention patents, 20 utility model patents and 3 registered trademarks.