Researchers have separated salt from seawater using solar power
Seawater purification follows the traditional process of heating the water, separating salt from it and capturing the pure evaporated water.
Do you know that 844 million people don't have access to clean water? And every minute a baby dies from infection caused by a lack of safe water and unclean environment. Seawater desalination and wastewater recycling are two artificial sources that can help us get pure water. And as seawater is abundant in quantity, why not harness it to get pure water? Researchers at Monash University have created a device that extracts pure water from seawater using solar power.
Seawater purification follows the traditional process of heating the water, separating salt from it and capturing the pure evaporated water. In the solar-powered method, the water is evaporated using the energy taken from sunlight. But, the constant process of evaporation and the salt left behind used block operating devices and are a major problem. With this new device, they have solved this problem.
The new device consists of a disc that uses a super-hydrophilic filter paper. It also consists of a layer of carbon nanotubes for light absorption. The saline water is transported using a 1mm diameter cotton thread to the evaporation disc. The filter paper traps the pure water and pushes the remaining salt to the edge of the disk.
How it works:
Researchers created a disc using a super-hydrophilic filter paper with a layer of carbon nanotubes for light absorption. A cotton thread, with a 1mm diameter, acted as the water transport channel, pumping saline water to the evaporation disc.
The saline water is carried up by the cotton thread from the bulk solution to the centre of the evaporation disc. The filter paper traps the pure water and pushes the remaining salt to the edges of the disc. According to researchers, this process is able to remove 100 percent of salt from the water. They also said that this method is cheap, practical, and effective, and can also be used in places that have no reliable source of electricity.
It is also different from other conventional methods as other methods require energy, which further leads to burning fossil fuel which pollutes the environment. Factually, we use about 3 percent of the world's energy supply in treating water.
The efficiency of the system was measured to be around 94 per cent. The disc used on the device can go to 25C to 30C within a minute. One of the researchers says that 'The innovative new device is capable of producing 6-8 litres (or 1.6-2.1 gallons) of clean water per square metre (10.8 square feet) of surface area per day.'
“We hope this research can be the starting point for further research in energy-passive ways of providing clean and safe water to millions of people, illuminating environmental impact of waste and recovering resources from waste."