How to realize efficient recycling of industrial wastewater?



"The utilization of sewage resources is an important embodiment of sustainable and green development, and is of great significance for alleviating the contradiction between supply and demand of water resources, reducing water environmental pollution and ensuring water ecological security in China." China's annual industrial water consumption accounts for about 20 percent of the country's total water consumption, and industrial wastewater emissions account for about 25 percent of the country's sewage emissions, Liu Guohua, deputy dean of the School of Environment at Renmin University of China, told People's Daily Online finance. Therefore, the recycling of industrial wastewater is an important part of the realization of sewage resources.

What's so good about this plan?

Industry, as one of the important areas of water use in China, will consume 102.89 billion cubic meters of water in 2020, accounting for 17.7% of the country's total water use, and industrial wastewater emissions account for about one-fifth of the country's sewage emissions. Liu Guohua said that China has a complete range of industrial categories and many enterprises, but the scale, facilities and technical reserves are uneven. Promoting the recycling of industrial wastewater is a long-term and arduous task, and the "Plan" emphasizes the strategy of focusing on key points and demonstration, adhering to the principle of classification and gradual progress.

Liu Guohua introduced that the "plan" focuses on the major water industries such as steel, petrochemical and chemical industries, nonferrous metals, paper making, textile and food, which have large wastewater discharge and upgrading conditions, and defines the overall goal of wastewater recycling in these industries, and makes clear the direction for China to further improve the recycling rate of industrial wastewater and accelerate the utilization of waste water resources in the next five years.

The "plan" proposes that by 2025, the reuse rate of industrial water above designated size in steel, petrochemical, chemical, non-ferrous and other industries will be further improved, and the reuse rate of industrial water above designated size in textile, paper, food and other industries will be increased by more than 5 percentage points from 2020.

"In some key water industries, the reuse rate of wastewater in steel, petrochemical, chemical, nonferrous and other industries has reached more than 93%, and can be further improved through efforts during the '14th Five-Year Plan' period." At the same time, the reuse rate of paper, textile, food and other industries is generally low, and should be effectively promoted according to the task requirements in the plan, by 2025, the reuse rate of industrial water above the scale is required to increase by more than 5 percentage points compared with 2020." Liu Guohua explained.

Liu Guohua also said that the "plan" focuses on six typical industrial industries, driven by innovative technology, takes engineering demonstration and promotion and application as the starting point, takes advanced water efficiency indicators and perfect standards as the guidance, and supports the cultivation of professional teams and the improvement of management level, highlighting seven key tasks and drawing a clear road map for further improving the recycling of industrial wastewater. At the same time, the improvement direction and specific measures are given for each key task in various industries, which strengthens the operability of industrial wastewater recycling and upgrading actions, and lays a solid foundation for steadily improving the recycling of industrial wastewater during the "14th Five-Year Plan" period.

How to achieve efficient recycling of wastewater in major water use industries?

In fact, as early as April 2015, The State Council issued the "Water Pollution Prevention and Control Action Plan" (referred to as the "Water ten") clearly pointed out that it is necessary to strengthen industrial water recycling and improve industrial water efficiency. In recent years, the recycling rate of industrial wastewater and water efficiency have made positive progress on the whole, and the reuse rate of industrial water above designated size has increased from 89% in 2015 to 92.5% in 2020, and the water consumption of 10,000 yuan of industrial added value in 2020 has decreased by 39.6% compared with 2015.

The "plan" mentioned that by 2025, we will strive to achieve a reuse rate of 94% of industrial water above designated size, greatly increase the amount of municipal recycled water for industrial use, reduce the amount of water consumed by 10,000 yuan of industrial added value by 16% compared with 2020, and basically form a new pattern of efficient recycling of wastewater in the main water industry.

So how do you achieve these goals? Liu Guohua said that first of all, we must adhere to scientific policies and focus on promoting. According to the characteristics of different typical industries, formulate feasible circuit diagrams and system technical schemes, and focus on promoting classification. In the six categories of key industrial industries, the focus is on improving the recycling rate of wastewater in the paper, textile and food industries.

Secondly, we should strengthen technological research and demonstration. Liu Guohua suggested that through the national science and technology innovation plan and other funding channels, support the research and development of efficient and low-cost treatment and reuse technology and equipment of industrial wastewater in different industries, in order to meet standards, and actively promote the demonstration and promotion of application in relevant industries.

Third, we should establish and improve the mechanism, incentive and guidance. Liu Guohua said that enterprises in typical industries that actively implement the recycling and transformation of industrial wastewater should be inclined in terms of tax policies and financial support, and enterprises in typical industries should be guided by incentive measures to actively implement water-saving transformation and wastewater recycling.

"Finally, in the process of promoting the recycling of industrial wastewater, it is necessary to strengthen the coordination function of the government, consolidate the responsibilities of departments at all levels, and play a good role in supervision and guidance." Adopt various forms of publicity to promote the participation of all sectors of society and enhance the enthusiasm of enterprises." Liu Guohua stressed.

How to break through the key core technology bottleneck through technological innovation?

The plan emphasizes the steady promotion of wastewater recycling technology transformation and upgrading, and the promotion of 100 advanced and applicable industrial wastewater recycling technology and equipment by 2025.

"The main driving force for the improvement of the recycling rate of industrial wastewater is the key core technology of various typical industries, strengthen the research of advanced technology and equipment, so that the wastewater can be standardized after treatment, and truly used for enterprise production." Liu Guohua said that during the "14th Five-Year Plan" period and even a longer period of time, we need to effectively promote the recycling of industrial wastewater by strengthening key technological research.

So, how to strengthen the key core technology research? Liu Guohua said that first of all, we should do a good job in the top-level design and planning of industrial wastewater recycling technology, deploy through national science and technology major projects, key research and development programs, and strengthen independent research and development; Secondly, the establishment of industry-university-research collaborative innovation model and mechanism, with industrial enterprises as the main body, jointly with the scientific and technological strength of high-level universities and research institutes, or training the research and development strength of scientific and technological enterprises to carry out key technology research, collaborative promotion, and promote the sound development of "promoting research with production and assisting production" in the field of industrial wastewater recycling; Finally, we should actively carry out international cooperation and exchanges, learn from and assimilate foreign advanced technologies, and enhance our independent innovation ability and international competitiveness.

Technological innovation is the main way to solve the key core technology of efficient recycling of industrial wastewater in China. Liu Guohua cited membrane separation, advanced oxidation, concentration and desalination, anaerobic biological nitrogen removal and other technologies as examples, which are the key core technologies for the recycling of industrial wastewater, but there are still many shortcomings, leading to the problems of high cost and low efficiency in the recycling process of industrial wastewater. Therefore, breaking through these key core technical bottlenecks through technological innovation can effectively help improve the recycling rate of industrial wastewater.

"It should be noted that the key core technologies of membrane separation, advanced oxidation, desalination and other industrial wastewater recycling are difficult to make breakthroughs in a short period of time, and it is necessary to actively support the research of these key technologies through various channels, and follow the law of scientific research, and can not be rushed." Liu Guohua said.