Expert interpretation: Accelerating the recycling of industrial wastewater to write a new chapter in water conservation for the construction of a beautiful China

China has abundant water resources, but the per capita water resources are only 1/4 of the global average. The contradiction between water supply and demand is prominent, with a normal annual water shortage of over 50 billion cubic meters. Meanwhile, with the acceleration of China's industrialization process and the diversification of product types, the composition of industrial wastewater has become more complex, leading to an increase in wastewater discharge. In 2021, with the approval of the State Council, ten departments issued the "Guiding Opinions on Promoting the Utilization of Sewage Resources", which deployed the comprehensive promotion of sewage resource utilization. As an important part of the "1+N" policy system for sewage resource utilization, the Ministry of Industry and Information Technology has issued the "Implementation Plan for Industrial Wastewater Recycling" (hereinafter referred to as the "Implementation Plan"), which proposes to focus on six typical industrial industries, deploy seven key tasks, and draw a clear roadmap for further promoting industrial wastewater recycling.

Green development is the ecological foundation of new industrialization, which requires us to embark on a sustainable development path with low resource consumption and minimal environmental pollution. Promoting the selection and scenario application of industrial wastewater recycling cases is conducive to reducing industrial production water consumption and wastewater discharge, guiding enterprises and parks to improve the reuse rate of water, and is an important means to alleviate China's water resource shortage, water environmental pollution and other problems. It is of great significance for promoting the technological transformation and upgrading of related industries, promoting industrial green development, and polishing the ecological background of new industrialization.

One is to strengthen top-level design and continuously improve the policy standard system. Since the release of the "Implementation Plan", various regions have actively responded, such as Sichuan Province issuing the "Implementation Plan for Promoting Industrial Wastewater Recycling in Sichuan Province (2024-2026)", proposing to focus on key water consuming industries and form wastewater recycling models with different emphases. Shandong has issued a list of key tasks for deep water conservation and control, conducted training for key monitored water using enterprises, and implemented the circular transformation of industrial parks in depth. At the same time, standard construction is an important part of promoting the recycling of industrial wastewater. Currently, the Ministry of Industry and Information Technology has established an overall working group for industrial water-saving standards and standardization working groups for industries such as steel, petrochemicals, light industry, textiles, and unconventional water utilization. They actively revise industry standards around basic common standards, as well as wastewater recycling technologies, processes, products, equipment, and materials.

The second is to adhere to goal orientation and significantly improve the efficiency of industrial water use. Since the release of the Implementation Plan, the Ministry of Industry and Information Technology, in conjunction with relevant departments, has released a catalog of industrial water-saving processes, technologies, and equipment encouraged by the state, formulated supply and demand docking guidelines, and vigorously promoted a number of advanced and applicable wastewater recycling technology and equipment around water scarce areas and water environment sensitive areas such as the Beijing Tianjin Hebei, Yellow River Basin, and Yangtze River Economic Belt. Guide enterprises and parks to actively carry out water efficiency benchmarking based on actual production, and promote the multi use and cascade utilization of water in enterprises through improving production processes, optimizing production processes, and building smart control systems. According to statistics, the water consumption per 10000 yuan of industrial added value in 2023 will be 24.3m3, a decrease of about 20% compared to 2020. A total of 21000 water-saving industrial enterprises have been built.

Thirdly, pilot projects will be launched to continuously expand the scenarios of wastewater recycling. According to the work deployment of the Implementation Plan, the Ministry of Industry and Information Technology has selected 29 pilot enterprises and 3 pilot parks with a focus on industries such as steel, petrochemicals, textiles, papermaking, and food, and many typical application scenarios have emerged. In terms of water circulation, for example, the Cangzhou Lingang Economic and Technological Development Zone has carried out the renovation of the sewage pipeline network, which uses "one plant, one pipe" to centrally treat sewage and reuse it in the production process. In terms of filling gaps, for example, Qian'an Iron and Steel Company of Shougang Corporation has developed comprehensive wastewater desalination and membrane long life control technology for steel production to solve the problems of frequent cleaning and short lifespan of reverse osmosis membranes. In terms of smart water management and control, Baosteel Zhanjiang Iron and Steel Co., Ltd. adopts centralized control, big data analysis, image recognition and other technologies to achieve "one map for production monitoring and one table for the entire plant water volume". In terms of regional integration of industry and city, Xinjiang Huatai Heavy Chemical Co., Ltd. uses recycled water produced by municipal sewage treatment plants to supplement the circulating water of cooling towers, achieving complete replacement of circulating cooling water with recycled water.

Where can the canal be so clear, for there is a source of living water. Next, it is recommended to collaborate on technology, standards, and mechanisms based on the selection of typical scenarios, further strengthen policy coordination and departmental collaboration, and promote the continuous improvement of the level of industrial wastewater recycling.

One is to promote innovation and application of wastewater recycling technology. Deploy innovative research on key technologies for industrial wastewater recycling, with a focus on breaking through technological bottlenecks such as high-performance industrial membranes and high concentration recalcitrant organic wastewater treatment. Cultivate a group of excellent wastewater treatment equipment and engineering application enterprises. Build a universal and integrated public service platform and industry alliance for wastewater recycling, carry out service to enterprise activities, and support industrial enterprises and parks to implement wastewater recycling technology upgrading and transformation.

The second is to establish a comprehensive control system for the entire process of wastewater recycling. Accelerate the revision of standards for industrial wastewater recycling technology, management, and evaluation, and build a smart management platform. Strengthen the rigid constraints on water resources and improve the assessment requirements for unconventional water utilization indicators such as wastewater and recycled water. Establish a sound monitoring system for the entire process of wastewater circulation water quality, gradually establish a risk prevention and early warning system covering the entire process of wastewater circulation, and ensure the safe utilization of wastewater circulation.