New Zealand Scientists Invent Steamin' Hot Sewage Recycling Solution

June 9th, 2010 by Tina Casey

We are always on the lookout for sustainable new developments in the burgeoning field of wastewater recycling, so of course this item from New Zealand caught our attention. A PhD project by a Victoria University student is undergoing commercial development as a means of reclaiming water, high-pressure steam, fertilizer products, and acetic acid from wastewater.

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The project offers a sustainable management solution for wastewater and runoff from dairy farms, wineries, and meatworks in New Zealand, which as Lord of the Rings fans know has some spectacular environments worth protecting as well as lots of sheep. Here in the U.S. there is a similarly motivated push by the EPA and Department of Agriculture to promote methane biogas production in the dairy industry. It’s the high pressure steam and acetic acid that give the New Zealand venture a new twist.

Wastewater Recycling and Wet Oxidation

The new process is called Wetox, as in wet oxidation, which is a means of removing suspended solids from wastewater using heat and oxygen under high pressure. Until now, the process has been used primarily for industrial wastes, and has not come into more widespread use in part due to its expense. The New Zealand researchers have developed a more cost effective method. New environmental regulations and the rising cost of waste disposal would also make an investment in Wetox more attractive. The byproducts could be used on site to help offset the cost, or sold off site.

Acetic Acid and Sustainable Chemicals

Currently, a good chunk of the world’s acetic acid supply comes from petroleum feedstocks. This ubiquitous chemical has a wide variety of uses in manufacturing, from plastics and glues to fabric, household cleansers, and food additives (vinegar is a dilute form of acetic acid). By offering a non-petroleum feedstock, Wetox is part of a green chemistry trend that seeks non-toxic, sustainable alternatives to petroleum and other toxic chemicals.

Image: New Zealand geyser by Alan Vernon on flickr.com.

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Tags: acetic acid, green chemistry, New Zealand, wastewater recycling, wet air oxidation

About the Author

Tina Casey Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.