Water resources are important factors of production, industrial production, but also its constraints. China's industrial use of water resources shortage, consumption of large, inefficient use of high intensity discharge of pollutants, and pollution tended to be worse. Wuhan University, Tian Jian-Ru, ZHOU Pei-jiang two experts noted the need for industry to save water from a strategic perspective the importance and urgency, and earnestly strengthen industrial water conservation work.

At present, the implementation of China's industrial water-saving through strengthening management, improving technology and developing non-traditional sources of water in three ways.

In the industrial water-saving management measures, mainly to strengthen the ideological education of water saving and water-saving laws and regulations, and strengthening the role of water regulating economic leverage to strengthen the industrial structure adjustment and carry out water balance testing. Combination of local water resources situation and the scale of production, the authorities introduced a targeted, practical water-saving policies, regulations, corporate water conservation principles, the irrational industrial structure has been adjusted. The implementation of scientific management methods, while saving water resources has also made considerable economic benefits to achieve efficient allocation and utilization of water resources. Measures in the industrial water-saving technologies, mainly reflected in the water-saving technology. By improving the process or using water craft to replace high water craft, in order to achieve little or no water for the purpose of water, and the conservation of resources while reducing environmental pollution.

The use of non-traditional sources of water as an alternative. Non-traditional water sources including rain, after recycling sewage water and seawater and air. Rain wide range of applications in foreign countries, China's western and northern parts of some provinces in the construction of farmland water conservancy created some experience. Aerial application of water in our country very few. Recycled water in industrial water use volume equivalent to only 0.4% of the quantity of water; seawater and brackish water in the industrial use of water in about 256 billion cubic meters, equivalent to only 21.3% in Japan, the United States, 12.8%. As the large quantity of renewable water and sea water, water quality and stability. While the industrial cooling water purity less demanding of water quality, and industrial use accounted for 70% -80%, consumption of large quantity, is the main thrust of the use of alternative water sources. Many of China's coastal cities, in particular, Dalian, Tianjin, Qingdao, Weifang, Yantai, Longkou and Shanghai's waterfront businesses have already made the direct use of seawater cooling water and the direct use of seawater desalination as a productive use of water. Seawater cooling techniques include cooling water technology and water circulation dc cooling technology.已建和在建production of water projects to use more seawater desalination reverse osmosis technology has now developed to the low-temperature multi-effect, nuclear energy technologies such as gado-effect evaporation, the scale is also growing. Low Temperature Nuclear Heating Reactor plus desalination feasibility study shows that the 10-ton cost of desalination of sea water tons of water can be controlled below 3.75 yuan, compared with the long-distance water transfer a strong competitive advantage. In the high-purity water in the economic benefits of good, tons of water cost 5 yuan, below the water depth of processing 8 to 13 yuan / t.

Experts believe that water-saving industrial processes has important practical significance. Process industries (including chemical, petrochemical, oil refining, pharmaceutical, paper making, metallurgy, electric power, food, consumer products, etc.) is both a major water users, but also large wastewater discharge. Water Pinch technology as a system water-saving approach is integrated in the water mass exchange in the field of applied science. The process of materials in direct contact with water, impurities in the process of materials (SS, pH, COD and some other constraints of the water quality of water reuse factor) in the role of the mass transfer driving force to enter the water, in the process be completed by the high concentration impurity area to the low concentration zone transfers. It can overcome the conventional wastewater reuse technology is limited to a single unit operation or in part, the shortcomings of water networks can be the greatest degree of recycling and reducing the amount of waste generated, and to minimize waste disposal costs. It is the principle of the use of impurity load equal to the optimal operation of water quantity and distribution of fresh water directly discharged waste water reuse or recycled wastewater is used to design or transform the business of water networks and to obtain the minimum water consumption of water networks, water and energy saving The dual purpose. The technology began in the mid-90s of last century, there are illustrated two forms of law and the mathematical method has been successfully applied in a variety of water-saving industrial processes. The technology has a number of engineering applications in foreign reports, but is rarely applied in our country.

Application of Water Pinch technology to save water for industrial processes, first of all be studied to determine the water system and the operation and limitations of impurities, clarify the operation of import and export restrictions on water flow and the impurity concentration, according to the order from small to large impurity concentration, each a concentration corresponding to a mass transfer both load and limit flow rate value, the largest flow rate value of the limit, shall seek the minimum amount of fresh water, its concentration shall correspond to the concentration of water pinch. If the operation of import and export traffic has changed the value should be calculated to reduce or increase the amount of fresh water. So the final minimum amount of fresh water should be added the need to add or subtract the increase in fresh water, fresh water consumption.

Potential for industrial water-saving, water-saving high efficiency, in line with recycling economic model, with increased resource use efficiency, reduce pollution emissions, re-use of technical features. Take the recycling economy development model is the direction of development of industrial enterprises, but also to achieve the sustainable use of water resources, the inevitable choice.