Post by account_disabled on Feb 20, 2024 5:10:15 GMT -5
About billion people worldwide drink water contaminated with disease-causing microbes. Conventional water treatment technologies include chemicals, which can produce toxic byproducts, and ultraviolet light , which takes a relatively long time to disinfect and requires a source of electricity.
Now, scientists at Stanford University and the SLAC National Accelerator Laboratory have invented a low-cost, recyclable powder that kills thousands of waterborne bacteria per second when exposed to sunlight to disinfect water. According to researchers, the discovery could be a significant breakthrough for the nearly % of the world's population who do not have access to safe drinking water.
The new disinfectant is a harmless metallic powder that works by absorbing both ultraviolet light and high-energy visible light from the sun. This sun-activated powder consists of nanometer-sized flakes of aluminum oxide, molybdenum sulfide, copper, and iron oxide. All of these materials are low-cost and quite abundant, and only a small amount of powder is required to treat a rel C Level Executive List atively large amount of water.
Users begin by stirring some of the disinfectant powder into bacteria-contaminated water, which is then exposed to direct sunlight. The molybdenum sulfide and copper catalyst absorb photons from the sun and then function as a semiconductor/metal junction, allowing the photons to give off electrons. These released electrons then react with the surrounding water, generating hydrogen peroxide and hydroxyl radicals that kill the bacteria by seriously damaging their outer protective membranes.
Chemical byproducts generated by sunlight also dissipate quickly. Once the purification process is complete, leftover hydrogen peroxide and hydroxyl radicals are quickly broken down into water and oxygen and disposed of in seconds. So you can drink the water immediately.
The non-toxic powder is also recyclable. Thanks to their iron oxide content, nanoflakes can be removed from water with a common magnet after disinfection. The powder is then loaded back into another beaker with contaminated water and the disinfection process is repeated.
In testing the technology, the Stanford and SLAC team added the powder to a -milliliter beaker of room-temperature water contaminated with about million E. coli bacteria per milliliter. Within just seconds of leaving it in real sunlight, no live bacteria were detected. Additionally, the team was able to use the same powder times to treat different contaminated water samples.
The researchers believe their new technology will facilitate revolutionary changes in water disinfection and inspire further innovations in this exciting interdisciplinary field. The powder could also be useful in wastewater treatment plants that currently use UV lamps to disinfect treated water.
"During the day, the plant can use visible sunlight, which would work much faster than ultraviolet light and probably save energy," said lead author Yi Cui. “Nanoflakes are fairly easy to make and can be scaled quickly by the ton.”
The Stanford and SLAC team plans to test the new dust on other waterborne pathogens, including viruses, protozoa and parasites that also cause serious illness and death.
Now, scientists at Stanford University and the SLAC National Accelerator Laboratory have invented a low-cost, recyclable powder that kills thousands of waterborne bacteria per second when exposed to sunlight to disinfect water. According to researchers, the discovery could be a significant breakthrough for the nearly % of the world's population who do not have access to safe drinking water.
The new disinfectant is a harmless metallic powder that works by absorbing both ultraviolet light and high-energy visible light from the sun. This sun-activated powder consists of nanometer-sized flakes of aluminum oxide, molybdenum sulfide, copper, and iron oxide. All of these materials are low-cost and quite abundant, and only a small amount of powder is required to treat a rel C Level Executive List atively large amount of water.
Users begin by stirring some of the disinfectant powder into bacteria-contaminated water, which is then exposed to direct sunlight. The molybdenum sulfide and copper catalyst absorb photons from the sun and then function as a semiconductor/metal junction, allowing the photons to give off electrons. These released electrons then react with the surrounding water, generating hydrogen peroxide and hydroxyl radicals that kill the bacteria by seriously damaging their outer protective membranes.
Chemical byproducts generated by sunlight also dissipate quickly. Once the purification process is complete, leftover hydrogen peroxide and hydroxyl radicals are quickly broken down into water and oxygen and disposed of in seconds. So you can drink the water immediately.
The non-toxic powder is also recyclable. Thanks to their iron oxide content, nanoflakes can be removed from water with a common magnet after disinfection. The powder is then loaded back into another beaker with contaminated water and the disinfection process is repeated.
In testing the technology, the Stanford and SLAC team added the powder to a -milliliter beaker of room-temperature water contaminated with about million E. coli bacteria per milliliter. Within just seconds of leaving it in real sunlight, no live bacteria were detected. Additionally, the team was able to use the same powder times to treat different contaminated water samples.
The researchers believe their new technology will facilitate revolutionary changes in water disinfection and inspire further innovations in this exciting interdisciplinary field. The powder could also be useful in wastewater treatment plants that currently use UV lamps to disinfect treated water.
"During the day, the plant can use visible sunlight, which would work much faster than ultraviolet light and probably save energy," said lead author Yi Cui. “Nanoflakes are fairly easy to make and can be scaled quickly by the ton.”
The Stanford and SLAC team plans to test the new dust on other waterborne pathogens, including viruses, protozoa and parasites that also cause serious illness and death.