Asking for water from the sea is no longer a dream? my country can desalinate more than 1.6 million tons of seawater every day!

Author: Duan Yuechu

Desalination technology is an important solution to the major challenges facing the world today. With the shortage of fresh water resources caused by population growth and climate change, desalination technology has become an indispensable way to supplement water resources. Through desalination technology, we can convert salt water into fresh water and solve the long-standing fresh water shortage problem faced by many parts of the world. This technology is of great significance to alleviating global water resource tensions and promoting sustainable social development.

The technology of desalination of seawater has been recorded as early as in ancient times. As early as in ancient China, people used lime to boil salt water for drinking, and the ancient Greeks also used the sun to evaporate salt water to obtain fresh water. The desalination technology, the crystallization of ancient human wisdom, laid the foundation for the development of today's desalination technology, and also proved the long-term demand and desire of mankind for the use of desalination technology.

With the development of modern science and technology, large-scale seawater desalination projects have adopted more efficient and energy-saving technologies. There are two main technical routes: thermal method and membrane method. Among them, the thermal method converts salt water into fresh water through evaporation and condensation; while the membrane method squeezes out the salt through high pressure. These two technologies provide feasible solutions for large-scale seawater desalination projects and provide important support for solving the global freshwater resource shortage problem.

Thermal desalination technology uses the physical process of evaporation and condensation to convert salt water into fresh water. First, the seawater is heated and evaporated, while the salt remains in place. Then, the evaporated water vapor is cooled by the condenser and condensed into liquid water, while the salt is left in the evaporator. This realizes the process of extracting fresh water from seawater. The characteristics of thermal desalination technology are that it can adapt to large-scale seawater desalination needs and has high water production efficiency. It provides reliable technical support for areas that meet large freshwater needs.

Membrane desalination technology is mainly divided into two methods: reverse osmosis and evaporation crystallization. Among them, reverse osmosis is to squeeze out the salt through high pressure, while evaporation crystallization is to separate the salt using the membrane in the evaporator. The membrane desalination technology can separate fresh water and wastewater more efficiently. Moreover, compared with the thermal method, the membrane method is more energy-saving and environmentally friendly. The characteristics of this technology are simple operation and low energy consumption, which is more suitable for small and medium-sized desalination projects.

my country has built 123 desalination projects with a daily desalination capacity of more than 1.6 million tons. According to the Action Plan for the Development of Seawater Desalination (2021-2025), by 2025, the total scale of seawater desalination in my country will reach more than 2.9 million tons per day, with an additional desalination scale of more than 1.25 million tons per day, including more than 1.05 million tons per day in coastal cities and more than 200,000 tons per day in island areas. The plan requires coastal water-deficient areas to use desalinated water as a supplementary water source for life, additional municipal water supply and important emergency backup water source, and to increase the proportion of desalinated water in water resources year by year; on the basis of protective development of islands, moderately advance the layout and construction of island desalination facilities to meet the water needs of production, life and ecology.

Although desalination technology has been widely used in solving the problem of freshwater shortage and promoting sustainable development in coastal areas, it also faces some challenges. For example, the cost of desalination is relatively high, including energy consumption, equipment investment and maintenance, which requires further independent intellectual property technology innovation and cost reduction measures. Another example is that the concentrated brine produced in the desalination process will have a certain impact on the marine ecosystem, and corresponding environmental protection measures need to be taken to reduce the negative impact on the ocean.

As the world's water shortage problem becomes increasingly serious, the development prospects of seawater desalination technology are very broad. First of all, seawater desalination technology will become an important means to alleviate the shortage of freshwater resources, especially for arid areas and island countries. Secondly, with the continuous innovation of technology, the cost of seawater desalination technology is expected to be further reduced, so as to better serve the development of freshwater resources around the world. In addition, the development of seawater desalination technology will also promote the healthy development of related industrial chains and provide more solutions for the sustainable use and management of water resources in the world.

References:

https://article.xuexi.cn/articles/index.html?art_id=5148997904837457166&item_id=5148997904837457166&study_style_id=feeds_default&pid=&ptype=-1&source=share&share_to=copylink