University of Cincinnati researchers have developed and tested a solar-powered nano filter that is able to remove harmful carcinogens and antibiotics from water sources lakes and rivers at a higher rate than the currently used filtering tech made of activated carbon.
In the journal Nano Letters,Vikram Kapoor,doctoral student,and David Wendell,assistant professor,report on their development and testing of the new filter made of two bacterial proteins that was able to absorb 64 per cent of antibiotics in surface waters versus about 40 per cent absorbed by the currently used filtering technology made of activated carbon.
One of the more exciting aspects of their filter is the ability to reuse the antibiotics that are captured. A
According to Wendell,the newly developed nano filters,each much smaller in diameter than a human hair,could potentially have a big impact on both human health and on the health of the aquatic environment (since the presence of antibiotics in surface waters can also affect the endocrine systems of fish).
Surprisingly,this filter employs one of the very elements that enable drug-resistant bacteria to be so harmful,a protein pump called AcrB. Wendell explained,These pumps are an amazing product of evolution.They are essentially selective garbage disposals for the bacteria.
Our innovation was turning the disposal system around.So,instead of pumping out,we pump the compounds into the proteovesicles. One other important innovation was the power source,a light-driven bacterial protein called Delta-rhodopsin which supplies AcrB with the pumping power to move the antibiotics.
The bacterial protein system has a number of advantages over present filtration tech,for example it is powered by direct sunlight vs.the energy-intensive needs for the operation of the standard activated carbon filter.
It also allows for antibiotic recycling.After these new nano filters have absorbed antibiotics from surface waters,the filters could be extracted from the water and processed to release the drugs,allowing them to be reused.
On the other hand,carbon filters are regenerated by heating,which burns off the antibiotics. So far,our innovation promises to be an environmentally friendly means for extracting antibiotics from the surface waters that we all rely on.
It also has potential to provide for cost-effective antibiotic recovery and reuse.Next,we want to test our system for selectively filtering out hormones and heavy metals from surface waters, said Wendell.
Wendell and Kapoor tested their solar-powered nano filter against activated carbon,the present treatment tech standard outside the lab,in water collected from the Little Miami River.
Using only sunlight as the power source,they were able to selectively remove the antibiotics ampicillin and vancomycin,commonly used human and veterinary antibiotics,and the nucleic acid stain,ethidium bromide,which is a potent carcinogen to humans and animals.