- Republished with permission of emagination, a School of Engineering electronic publication
Dr. Jeffrey McCutcheon has been awarded two grants in support of his research program, which involves the use of forward osmosis and membrane filters to remove contaminants from water. The Environmental Protection Agency, through its “Science to Achieve Results” (EPA STAR) Early Career program, which focuses on research aimed at advancing public health through improved water infrastructure, awarded him $300,000. He received the second grant from 3M Corporation, which presented him a 3M Non-tenured Faculty Grant.
Dr. McCutcheon, an assistant professor with dual appointments in the Chemical, Materials & Biomolecular Engineering department and the Center for Environmental Sciences and Engineering (CESE), joined UConn in 2008. He received his Ph.D. from Yale University in 2007 and has conducted extensive research on forward osmosis (FO) processes, most notably for desalination, with his thesis advisor, Dr. Menachem Elimelech.
Dr. McCutcheon described forward osmosis as an osmotically driven membrane separation process based on the natural tendency of water to flow from a solution of low solute concentration to one of higher concentration. In this process, a relatively dilute feed water – such as seawater, brackish water or wastewater – flows along one side of a membrane, while a more concentrated ‘draw’ solution or osmotic agent flows on the opposite side of the membrane. Clean water permeates through the membrane from the feed water to the draw solution, leaving behind salts, contaminants and other feed solutes as a concentrated brine stream.
In contrast with reverse osmosis, the wastewater treatment standard, Dr. McCutcheon noted, the FO separation process requires no energy. The draw solution can then be used or removed, recovered and recycled. Some researchers estimate that in certain applications, this method could result in a 50% cost savings over reverse osmosis, while dramatically reducing the carbon footprint. In previous research, Dr. McCutcheon has identified several viable draw solutions, so his focus now is on the design of a suitable membrane; this, he said, is the single largest obstacle to adoption of the FO separation technology.
For the EPA STAR project, “We will evaluate how well different membranes remove the contaminants found in wastewater in forward osmosis,” he said. Municipal wastewater is commonly contaminated with bacteria, viruses and other microbes; toxins such as arsenic, chromium and lead; emergent contaminants from pharmaceutical drugs (such as hormones) and pesticides, which disrupt endocrine function in humans and other creatures; salts, and other contaminants.
A second facet, he explained, “will focus on examining fouling of the membrane, which can result from the accumulation and interaction of the contaminants on the wastewater side of the filter. These include fats, oils and other lipids that can create a film over the membrane, slowing the flow of water.” Dr. McCutcheon will evaluate this emerging technology for the first time for the removal of these specific compounds.
This work will result in the evaluation of a new technology that may lead to more energy efficient, cost effective wastewater treatment. According to EPA reports, energy costs can account for 30 percent of the total operation and maintenance costs of wastewater treatment plants, and nationwide, these facilities account for approximately three percent of the total electric load. These factors make wastewater treatment facilities attractive focal points for reducing energy consumption while improving the production of clean water. Dr. McCutcheon’s project represents an important step toward the development of more sustainable water purification processes world-wide, according to Dr. McCutcheon.
Dr. McCutcheon’s 3M Nontenured Faculty Grant, which awards him $15,000/year for up to three years, will support his work on two types of electrospun nanofiber membranes for water filtration applications. He was nominated for the award by Thomas J. Hamlin, Senior Vice President of R&D at 3M Purification in Meriden, CT. Dr. McCutcheon explained that membranes made from electrospun nanofibers are especially attractive thanks to their high surface area for capturing contaminants. This funding will support Dr. McCutcheon’s research efforts on polymeric nanofiber mediated water filtration. Polymer nanofibers are a new type of material with applications to water filtration. Dr. McCutcheon’s work aims to optimize the nanofiber strength, size, and morphology. The 3M grant will allow Dr. McCutcheon and his team to design, fabricate and test polymeric nanofiber material as novel filtration media.