Skip to main content

Engineered sand could remove nasty toxins to produce drinkable water

Water is one of our most underappreciated resources. For people with steady access to this life-giving liquid, it’s absence can seem like a distant dystopian nightmare. But some 783 million people lack clean water worldwide, according to the World Health Organization, and even in the United States, parched communities suffer from prolonged droughts.

Researchers at the University of California, Berkeley are working on a low-cost solution to make better use of the water at hand. They’ve engineered sand, coating the grains in compounds that react with and help destroy organic pollutants found in stormwater. The solution could be used to help support local sources of potable water for water-stressed communities.

Related Videos

“In all but the most arid places, enough rain falls within the city limits to provide the water we drink and use in our homes,” David Sedlak, a civil and environmental engineering at UC Berkeley who advised on the project, told Digital Trends. “Unfortunately, we cannot build reservoirs in a crowded city and rain barrels are too small to hold all of the water that we need. To capture the rainwater that falls in our cities, engineers have developed new approaches for infiltrating rainwater into the ground, where it can be stored in groundwater aquifers.”

The problem is that a lot of rainwater drains off rooftops, sidewalks, and parking lots, which pollute it with organic gunk and chemicals, and make it utterly unusable.

Sedlak and graduate student Joseph Charbonnet developed what they hope may provide a low-cost solution for decontaminating stormwater for drinking and household use. Coating sand in two kinds of manganese that react to form manganese oxide produces engineered sand thatbinds to chemicals like herbicides and pesticides and pulls them out of the water.

“If we are going to treat [water] as it infiltrates into the ground, we need to apply technologies that are simple, inexpensive, and do not require a lot of oversight,” Sedlak said. “Rainwater is typically introduced to aquifers by allowing it to percolate through sand. We have invented a new way of coating the surface of sand grains with a thin layer of manganese oxide.”

The research team’s idea is to add an engineered sand to current water reclamation basins, where standard sand is currently used. The stormwater would then be partially decontaminated as it percolates through the sand and into an aquifer. During rainy months, the aquifer would replenish, providing a source of water through the dry season.

The Berkeley team’s engineered sand doesn’t remove all contaminants, meaning it would need to be used in conjunction with other types of purification systems to make it potable. Sedlak pointed to the complementary work at the National Science Foundation’s Engineering Research Center for Reinventing the Nation’s Urban Water Infrastructure, where they create materials to remove toxic metals and pathogenic microbes.

A paper detailing the research was published last month in the journal Environmental Science & Technology,

Editors' Recommendations

No, this funky light show on the space station is not a disco
The International Space Station’s solar arrays provide power for the orbiting laboratory. NASA will install a total of six new roll out solar arrays in front of the existing arrays at 1A, 2B, 3A, 3B, 4A, and 4B to augment the power. During the Aug. 24 spacewalk, NASA astronaut Mark Vande Hei and astronaut Akihiko Hoshide of the Japan Aerospace Exploration Agency will install the modification kit on the 4A power channel, where the next new roll out solar array will be installed in 2022.

A funky light show captured this week by astronaut Thomas Pesquet made the International Space Station look more like an orbiting disco than an orbiting laboratory.

https://twitter.com/Thom_astro/status/1434227271926222853

Read more
Initiatives for 24/7 clean energy announced at Google I/O 2021
google clean energy plans goolge campus dragon scales

Google has maintained a focus on carbon neutrality, becoming carbon neutral in 2007 and matching all of its electricity usage with clean energy purchases since 2017. Devices like Nest speakers and displays use recycled plastics in their manufacturing, and we continue to see Google strive for improvement in this area. At Google I/O 2021, the company announced more initiatives towards cleaner energy, with the aim of operating on carbon-free energy by the year 2030.

One of the ways Google aims to achieve its carbon-free effort is through the use of carbon-aware computing. The brand will use certain data centers for specific tasks depending on the availability of carbon-free energy sources. This means its data centers can take advantage of times and instances when carbon-free energy sources are more readily available, moving tasks so it can use more of the existing clean energy that's already available. Google says it is going to start by applying this to media processing -- YouTube, Photos, Drive, etc. All of this will be done in the background, so users will still be able to use their applications as usual.

Read more
Tech for Change: At CES 2021, tech promises to create clean, pure water for all
The AcquaTap from Exaeris

CES, the leading gadget show in the country, promises no shortage of new TVs, exoskeletons, headphones, and even emotional robots that might be a great companion for your child. But beyond the bleeding-edge gadgets and consumer electronics, there are a number of companies using high tech to solve the lowest of problems: There’s simply not enough clean drinking water in the world.

Some 20% of people reportedly lack access to drinking water, and can’t simply “turn on the faucet.” Meanwhile, corporations around the globe contaminate more water than they ever purify. Fortunately, tech can help, thanks to companies like Exaeris Water Innovations, which last year announced and this year plans to roll out the AcquaTap, a remarkable portable system for pulling water directly from the air all around you. The device can make up to 5 gallons per day, the company says.

Read more