Rice shows reusable, carbon nanotube-reinforced filters clean toxins from water
Carbon nanotubes immobilized in a tuft of quartz fiber have the power to remove toxic heavy metals from water, according to researchers at Rice University.
Prize-winning filters produced in the lab of Rice chemist Andrew Barron by then-high school student and lead author Perry Alagappan absorb more than 99 percent of metals from samples laden with cadmium, cobalt, copper, mercury, nickel and lead. Once saturated, the filters can be washed with a mild household chemical like vinegar and reused.
The researchers calculated one gram of the material could treat 83,000 liters of contaminated water to meet World Health Organization standards — enough to supply the daily needs of 11,000 people.
The lab’s analysis of the new filters appears this month in Nature’s open-access Scientific Reports.
The robust filters consist of carbon nanotubes grown in place on quartz fibers that are then chemically epoxidized. Lab tests showed that scaled-up versions of the “supported-epoxidized carbon nanotube” (SENT) filters proved able to treat 5 liters of water in less than one minute and be renewed in 90 seconds. The material retained nearly 100 percent of its capacity to filter water for up to 70 liters per 100 grams of SENT, after which the metals contained could be extracted for reuse or turned into a solid for safe disposal.
While the quartz substrate gives the filter form and the carbon nanotube sheath makes it tough, the epoxidation via an oxidizing acid appears to be most responsible for adsorbing the metal, they determined.
Alagappan, now an undergraduate student at Stanford University, was inspired to start the project during a trip to India, where he learned about contamination of groundwater from the tons of electronic waste — phones, computers and the like — that improperly end up in landfills.
“Perry contacted me wanting to gain experience in laboratory research,” Barron said. “Since we had an ongoing project started by Jessica Heimann, an undergraduate who was taking a semester at Jacobs University Bremen, this was a perfect match.”
Barron said the raw materials for the filter are inexpensive and pointed out the conversion of acetic acid to vinegar is ubiquitous around the globe, which should simplify the process of recycling the filters for reuse even in remote locations. “Every culture on the planet knows how to make vinegar,” he said.
“This would make the biggest social impact on village-scale units that could treat water in remote, developing regions,” Barron said. “However, there is also the potential to scale up metal extraction, in particular from mine wastewater.”
Learn more: Heavy metals in water meet their match
The Latest on: Toxic heavy metals
- Toxic metals found in groundwater in almost all states of India; its impact on healthon August 3, 2022 at 4:49 am
Data presented by the government shows that not only is groundwater, a major source of drinking water in India, depleting, but citizens in most parts of the country have been exposed to excess amounts ...
- How flood maps can illuminate the risk from toxic waste siteson August 2, 2022 at 11:00 pm
The strongest predictor that a neighborhood contains a flood-prone site of former industrial pollution is the proportion of nonwhite and non-English-speaking residents.
- Are You Drinking Poison? Toxic Metal Found in Groundwater in Almost All States, Says Govt Dataon August 2, 2022 at 1:58 am
Toxic metals like arsenic, iron, lead, cadmium, chromium and uranium found in groundwater in many districts of almost all the states in the country.
- It’s poison, not water! Govt data shows toxic metals in groundwateron August 2, 2022 at 1:50 am
The central government has told the Rajya Sabha that in almost all the states of the country, the amount of toxic metals in groundwater has been found to be more than the prescribed standard.
- How burn pits may have raised veterans' risk of rare cancers and respiratory illnesseson July 30, 2022 at 3:00 am
Republican senators who previously supported a bipartisan bill to expand health care for veterans exposed to toxic burn pits reversed their stance on Thursday.
- Adsorbent material filters toxic chromium, arsenic from water supplieson July 26, 2022 at 10:34 am
Researchers at the Department of Energy's Oak Ridge National Laboratory are tackling a global water challenge with a unique material designed to target not one, but two toxic, heavy metal pollutants ...
- FDA's ongoing analysis finds toxic arsenic, lead in certain baby foods — tips for parents to limit exposureon July 26, 2022 at 9:35 am
The FDA’s ongoing analysis in an effort to lower toxic heavy metals in baby foods found that levels of lead in baby food sweet potatoes and teething biscuits were among the highest of all foods tested ...
- The US can’t get away from lead’s toxic legacyon July 26, 2022 at 6:00 am
A prized industrial product since the birth of America, the heavy metal has created a costly, pervasive, and deadly mess.
- New Atlanta Baby Store Meets High Demand for Non-Toxic Good-quality Productson July 26, 2022 at 2:00 am
The Eden Baby of Atlanta, GA is a new baby and children’s store featuring everything from non-toxic toys, organic and bamboo clothes, books, and other natural baby/toddler accessories. The founders, a ...
- Chinese artist stirs climate action with toxic soup and heavy metal musicon July 25, 2022 at 7:32 am
One early morning after the rain in the eastern Chinese city of Zibo, two people dressed as fishermen stir dozens of giant inflatable fish and peppers in the polluted, dark-brown water of the Yueyang ...
via Google News and Bing News