Removing very dilute concentrations of pollutants from water, existing separation methods tend to be energy- and chemical-intensive. Now, a new method developed at MIT could provide a selective alternative for removing even extremely low levels of unwanted compounds.
The system uses a novel method, relying on an electrochemical process to selectively remove organic contaminants such as pesticides, chemical waste products, and pharmaceuticals, even when these are present in small yet dangerous concentrations.
The approach also addresses key limitations of conventional electrochemical separation methods, such as acidity fluctuations and losses in a performance that can happen as a result of competing for surface reactions.
In the new system, the water flows between chemically treated, or “functionalized,” surfaces that serve as positive and negative electrodes. These electrode surfaces are coated with what is known as Faradaic materials, which can undergo reactions to become positively or negatively charged.
These active groups can be tuned to bind strongly to a specific type of pollutant molecule, as the team demonstrated using ibuprofen and various pesticides. The researchers found that this process can effectively remove such molecules even at parts-per-million concentrations.
The research team included Kyle Smith; a professor of mechanical science and engineering at the University of Illinois, Kai-Jher Tan, Johannes Elbert, and Robert R. Taylor Professor of Chemistry Timothy Jamison at MIT; and Christian Ruttiger and Markus Gallei at the Technical University of Darmstadt. The work was supported by a seed grant from the Abdul Latif Jameel World Water and Food Security Lab (J-WAFS) at MIT.
The research team has already racked up a series of honors for the ongoing development of water treatment technology, including grants from the J-WAFS Solutions and Massachusetts Clean Energy Catalyst competitions, and the researchers were the top winners last year’s MIT Water Innovation Prize.
The researchers have applied for a patent on the new process.