Ozone Technology to be Tested in Soil Cleanup Demo

Civil and environmental engineering professor Andy Hong at University of Utah in Salt Lake City has partnered with Chinese environmental cleanup company Honde LLC to use Hong’s method of heightened ozonation treatment (HOT) to clean metals and other contaminants from polluted soil along the shores of Lake Taihu near Wuxi, China.

Hong’s HOT technology infuses water or soil with pressurized ozone gas microbubbles that exposes pollutants and makes them easier to remove. The work in China will test a new process, which until recently had not been demonstrated outside of Hong’s lab.

The Chinese government has given Hong and HOT a stiff test: an industrial site on the shore of Lake Taihu, about half the size of the Great Salt Lake in Utah, adjacent to Wuxi, a major Chinese city west of Shanghai with a population of about 4.5 million. The lake is polluted by numerous contaminants. Wuxi is an industrial city in a region with a number of polluted factory sites. The lake receives runoff from across the region, which causes nutrients to collect in the lake and feed harmful algae.

The demonstration project began in September and is expected to last three months. The focus of the test is removing heavy metals and other contaminants from the soil.

The centerpiece of equipment is a HOT reactor (pictured below), which is a pressurized metal vessel that produces ozone microbubbles placed on the site to be cleaned. Contaminated soil is excavated and placed into the device. Organic contaminants (hydrocarbons) are removed first by repeatedly pressurizing and depressurizing the reactor with ozone gas, creating microbubbles that degrade the hydrocarbons. Metal contaminants are removed by adding a chemical agent to extract them, then adding lime to precipitate the contaminants so they can be filtered out and then disposed.

While the reactor is being used to treat soil, but it can also be used to treat water, algae or sewage waste. In addition to Honde, 7Revolutions Energy Technology Fund — an investment company based in Salt Lake City and a University of Utah startup — has licensed the technology and started a company to explore uses in North America and elsewhere.

Heightened Ozonation Treatment reactor (Honde LLC)