Scrubbing Micro-Bubbles Clean Polluted Lake.
Environmental remediation can take what feels like forever, and entirely removing an oil sheen from water is especially tough. An advanced technological process involving microbubbles could do the trick.
Andy Hong, a civil and environmental engineering professor at the University of Utah, developed a process in the lab where polluted water or soil is infused with pressurized ozone gas microbubbles. The bubbles are smaller than those in standard ozone aeration, meaning they are extremely effective at turning oil droplets into chemicals that can easily get filtered afterward. Pressurization helps the ozone completely saturate the water.
Last November Hong published his research in the journal Chemosphere but it has since come out of the lab and been applied to an extremely polluted lake in China. Lake Taihu, west of Shanghai and close to the city of Wuxi, is full of runoff from industrial sites nearby. Working with the Chinese environmental cleaning company Honde LLC, Hong is heading up a three-month project to test his process. The team is putting polluted soil in a "heightened ozonation treatment" reactor to break down hydrocarbons and remove metal contaminants, then lime is added to help filter them out.
The process has the potential to clean a range of seriously problematic pollutants, including oily water from drilling on land, groundwater containing the gasoline additive MTBE, wastewater containing pharmaceuticals, soil filled with polychlorinated biphenyls (PCBs), heavy metals and oil refinery waste.
If Hong can prove his technique at the lake, the university reports that he will try it in North America with help from a Salt Lake City investment firm that has licensed the technology. The U.S. could definitely use a hand. Over the past 15 years, the federal Superfund cleanup program has had few resources to deal with sites where responsibility was hard to assign or where the polluter had gone bankrupt. Hundreds of sites like this still need to be cleaned. Oh, and so does the Gulf.
We'll see if microbubbles will be able to handle mega jobs.
Photos: (Top) Professor Andy Hong with his reactor in the lab last year; (bottom) University of Utah engineers use the silver tank reactor on the left to clean soil from a lake in China. Credits: University of Utah College of Engineering and Honde LLC.