By Peter Chawaga
As water treatment technology becomes more sophisticated and regulations more robust, the industry’s focus is migrating from the elimination of pathogens to the fight against emerging contaminants and trace pollutants.
While utilities are first and foremost concerned with major impurities, they are increasingly preparing to combat even the smallest of concerns now entering water supplies. Helping in their ability do so has been new research like that of Dr. Shaily Mahendra, a professor of environmental engineering at the University of California, Los Angeles.
“With the growth of synthetic chemical usage in industrial and commercial products, the main threats in drinking water are transitioning from pathogens and particles to emerging contaminants,” said Mahendra. “The current technologies are not always effective or are too expensive to remove water pollutants, and especially those contaminants that are detected in trace amounts but still pose health risks… Our work will develop an innovative, enzyme-based technology to remove or destroy water contaminants cheaply and sustainably.”
Mahendra and her team have been focusing on a method for packaging enzymes capable of destroying contaminants through biodegradation together in nanoparticle “vaults.” By encapsulating up to 80 enzymes this way, these vaults can remove a variety of contaminants, even the trace ones that are of emerging concern, at once.
“Enzymes are proteins that mediate nearly all the biochemical reactions in living cells,” Mahendra said. “With packaging into vaults, the enzymes will be active longer and react faster; that will bring the cost down… If one or more enzymes involved in biodegradation of multiple co-contaminants are packaged inside vaults, such vaults can potentially be a ‘one-stop-shop’ for removing a suite of water contaminants.”
While Mahendra concedes that much research is still needed and that the novel technology is currently costly to implement, a scaled-up version of the production would be safer, cheaper, and more sustainable than current technology used to remove emerging contaminants.
Mahendra’s lab has made some progress in adopting what has long been a tool for biomedical applications like tumor control and vaccine delivery and the next steps will be immobilizing the enzyme vaults in sol-gels, which would help scale up production and integrate vaults at treatment plants.
“To adapt this really cool nanobiotechnology … for solving environmental problems has been challenging but very rewarding,” Mahendra said. “We need to continue the research and remonstration efforts but also educate the water treatment community of academics and professionals in this new area and getting them excited about its beauty and power.”
Noting the potential of this research to address growing concerns in the treatment industry, the Water Environment & Reuse Foundation (WE&RF) awarded Mahendra its 2017 Paul L. Busch Award and accompanying $100,000 prize.
“The aim of the Paul L. Busch Award is to further the body of applied research and basic research that makes a clear connection to practical application and potential for improving the water environment,” said Dr. Amit Pramanik, the chief innovation and development officer at WE&RF. “Successful completion of [Mahendra’s] research could revolutionize both groundwater and water treatment by using a relatively low-cost, elegant approach to remove some of the most recalcitrant chemicals of concern.”
As Mahendra and her team continue to look for the financial support necessary to continue their research, with pilot demonstrations and then efforts to scale up on their horizon, it’s hoped that this prize will be the boost they need to get there.
“This no-strings award provides researchers the creative liberty to explore new ideas and take risks on innovative research that otherwise might not get support from other funding sources,” Pramanik said. “This helps push ideas on the brink of discovery forward to benefit the larger water community, the public, and the environment. It also recognizes the researcher and their team — spurring them on for further recognition and providing additional opportunities for funding from other sources.”