Solve global shortage of freshwater

Researchers at Yale University in the United States said that improved seawater desalination technology should play an important role in helping to combat freshwater shortages worldwide.

Some countries have met the people's clean water needs by exploiting natural freshwater resources.

Among all the methods to help preserve and reuse freshwater resources . have been utilized, the improved seawater desalination technology, can be implemented at a reasonable cost and energy saving. .

More than one third of the world's population has lived in areas where freshwater demand is becoming increasingly urgent. By 2025, this number will almost double. Some countries have sought to meet people's clean water needs by exploiting freshwater resources in nature. However, this approach still does not provide a sustainable perspective in the long term, which has been demonstrated through many events. The Jordan River (this is a river in Southwest Asia, 251 km long, flowing from the foot of Mount Hermon to the Dead Sea) is one of the most sacred rivers in the world, gradually being depleted.

" The global oceans are an almost endless supply of water, but the ocean removal technique is very expensive and consumes a lot of energy, " according to Menachem Elimelech, a chemistry professor and Environmental engineering, working at Yale University, USA and the leading author of this research.

The results of this study were published in the journal Science, August 5, 2011.

Reverse osmosis forces seawater to flow through a salt filter as the leading method for seawater desalination.

For years, scientists have focused on increasing the water content of this salt filter, using new materials, such as carbon nanotubes, to minimize the energy needed to push water through it.

In the new study, Elimelech and William Phillip, working at the University of Notre Dame, USA, demonstrate reverse osmosis requires at least the amount of energy that cannot be overcome, and current technology has begun to approach. limit.

Instead of focusing on finding new materials to create salt filters with higher water flux, Elimelech and Phillip said that it would be more effective to focus on studying the period before and after the reduction. salt.

Natural organic matter and particulate matter available in seawater need to be removed before the seawater flows through the salt filter. Chemicals will be added to seawater to clean and help remove impurities more easily in the period before salt filtration.But the problem is whether the salt filter can recover organic matter on its surface, because almost all impurity filtration processes before salt filtration are successful, according to scientists' conclusions.

In addition, Elimelech and Phillip calculate that a salt filter is capable of filtering out natural minerals in seawater such as boron and chloride that will help save energy and costs considerably. More than 70% of the world's freshwater is used in agriculture, but clean water contains natural minerals available in seawater such as low concentrations of boron and chloride, which cannot be used for these purposes. . Therefore, the removal of these minerals is separated, in the period after salt filtration.

Currently, scientists believe that it is possible to develop a membrane that can filter salt, and can filter natural minerals such as boron and chloride at the same time.

Elimelech warns: we should be aware that seawater desalination is only considered as a last resort in efforts to provide clean water on a global scale. This suggests that more long-term research is needed to determine the environmental impacts of seawater desalination technology.

However, seawater desalination technology has played an important role in maintaining the current and future human existence.

" All of this will require new materials and new chemistry, but we believe this is the direction, but we should focus our efforts on moving forward ," Elimelech said. " The problem of water shortage will become more serious, and we need to be ready to deal with challenges by improving and applying seawater filtration technology in a sustainable way ."