According to a UN report more than 780 million people worldwide lack basic clean drinking water, and by 2025, half of the world’s population will be living in drought affected areas, along with a staggering population growth of over 10 billion people by 2050, and over 10.9 billion by 2100.
Ironically, about 71% of the Earth’s surface is covered by water, and almost 97% is ocean seawater, according to the US Environmental Protection Agency (EPA).
Seawater, up until now, wasn’t safe for human drinking consumption. However, thanks to a group of dedicated scientists in Australia they have been able to transform seawater into safe, clean drinking water using the power of the sun along with metal-organic frameworks (MOFs), in less than 30 minutes.
The pioneering technique, first introduced in 2015, could provide access to clean purified water for millions of people across the world by simply filtering harmful particles, not only from seawater, but also from contaminated riverbeds, lakes and streams.
Researchers were able to filter harmful particles from water and generate 139.5L of clean water per kilogram of MOF per day, but also perform this task in a more energy-efficient manner than current desalination practices.
The science behind this breakthrough technology uses a metal-organic compound consisting of metal-ions that form a crystalline material with the largest surface area of any known material.
Lead author Professor Huanting Wang from the Department of Chemical Engineering at Monash University in Melbourne, described the new method using sunlight, along with MOFs, for energy-efficient and sustainable desalination and water purification.
“Desalination has been used to address escalating water shortages globally. Due to the availability of brackish water and seawater, and because desalination processes are reliable, treated water can be integrated within existing aquatic systems with minimal health risks.”
“But, thermal desalination processes by evaporation are energy-intensive, and other technologies, such as reverse osmosis, have a number of drawbacks, including high energy consumption and chemical usage in membrane cleaning and dichlorination.”
Professor Wang continued; “Sunlight is the most abundant and renewable source of energy on Earth. Our development of a new adsorbent-based desalination process through the use of sunlight for regeneration provides an energy-efficient and environmentally-sustainable solution for desalination.”
According to the World Health Organization (WHO), good quality drinking water should have a total dissolved solid (TDS) of less than 600 parts per million (ppm).
However professor Wang’s team of researches were able to achieve a TDS of less than 500 ppm in just 30 minutes and regenerate the MOF for reuse in four minutes under sunlight.
This new developing technology hopes to eliminate once and for all, the catastrophic event that befell South Africa in 2017 and 2018, when the country suffered an historic and prolonged period of abnormally low rainfall, leading to a severe drought in the Western Cape region, most notably affecting the City of Cape Town when water levels hovered between 15 and 30% of total dam capacity.
The government was forced to mandate significant water restrictions resulting in millions of crops and livestock being destroyed. Eventually the restrictions were successful after the government reduced consumption by more than 500 million liters (130,000,000 gallons) per day, before conditioned improved.
However, South Africa is a naturally water scarce country, ranked 30th in the world. This emerging technology will save countless lives, by purifying contaminated wastewater that would otherwise be ignored.