Mat baits, hooks and destroys Pollutants in Water

A polymer mat developed at Rice University has the ability to fish biologically harmful contaminants from water through a strategy known as “bait, hook and destroy.” It was developed by scientists with the Rice-led Nanotechnology-Enabled Water Treatment (NEWT) Center.

The mat depends on the ability of a common material, titanium dioxide, to capture pollutants and, upon exposure to light, degrade them through oxidation into harmless byproducts.

The NEWT mat simplifies the process. The mat is made of spun polyvinyl fibers. The researchers made it highly porous by adding small plastic beads that were later dissolved with chemicals. The pores offer plenty of surface area for titanium oxide particles to inhabit and await their prey.

The mat’s hydrophobic (water-avoiding) fibers naturally attract hydrophobic contaminants like the endocrine disruptors used in the tests. Once bound to the mat, exposure to light activates the photocatalytic titanium dioxide, which produces reactive oxygen species (ROS) that destroy the contaminants.

Not only it destroys the pollutants faster, but also significantly decrease the electrical energy per order of reaction. This is a measure of how much energy you need to remove one order of magnitude of the pollutant, how many kilowatt hours you need to remove 90 percent or 99 percent or 99.9 percent.

As you move from treating distilled water to wastewater treatment plant effluent, the amount of energy required increases 11-fold. But when you do this with mat immobilized bait-and-hook photocatalyst, the comparable increase is only two-fold. It’s a significant savings.