A team of engineering students from the University of Wisconsin-Madison (UW) took first place in a recent American Society of Civil Engineers (ASCE) competition with a bit of guidance from FPL Research Chemist Mandla Tshabalala.
The contest, part of the annual ASCE Great Lakes Student Conference, challenged students from 18 regional universities to design and build a water filter for a hypothetical water stream contaminated with dissolved copper, molybdenum, iron, and phosphate. Filters were scored on cost, sustainability, and performance.
Students were encouraged to pursue filter materials that were easily available to consumers or waste products that could be given a second life. In researching their options, the team (composed of Jack Richeson, Adam Dircz, and Brian LaQua) came across Tshabalala’s work on using wood in water filters, an arena he has been exploring for more than a decade.
Tshabalala met with the students and discussed the possibilities of wood for water filtration. He helped them consider various options for wood material, provided his research publications for background information, and showed them water filters he had designed, all the while encouraging the team to come up with a unique design and method of their own.
The students chose ponderosa pine bark as one of the filter media because it is readily available, cheap, and sustainable, and has been shown to remove copper and iron. Bark is a commonly available byproduct of timber processing mills; one FPL study estimates that the United States generates around 2.2 million metric tons of bark residues annually.
Along with pine bark, the winning filter employed sand and steel slag, a waste product of the steel industry. The design won first place by removing 83 percent of the contamination.