Just in time for the holiday drinking season, here comes news of a more sustainable cocktail of the future, and it’s all thanks to a vibrating membrane. Hey, it’s not what you think (just guessing here). The vibrating membrane refers to a proprietary wastewater treatment system developed by the company New Logic Research, specifically to deal with waste from olive processing. If you didn’t know that the olive industry has a wastewater problem, join the club, but apparently it’s a big one to the tune of 600 million gallons per year in California alone.
Olive Wastewater, What a Headache
According to a quite informative article at oliveoilsource.com, one key issue with olive wastewater is that it is loaded with polyphenols, a class of antioxidants.
When we eat foods containing antioxidants, that’s a good thing, but what makes antioxidants good for humans is their anti-bacterial nature. When released into the environment, the polyphenol-saturated wastewater from olive mills can wreak havoc with the existing balance and contaminate wetlands and other waterways, including groundwater.
The conventional “safe” disposal method, according to New Logic, is to let the excess liquid in the wastewater evaporate in open ponds. Centrifuges are another means of removing most of the liquid. The remaining sludge can then be sent to a landfill or, in some cases, used as a soil enhancer.
There are a couple of big problems with this. The open-pond method takes up a large amount of space that could be put to more productive use. Leakage is a risk, and odors create problems with neighbors, especially as population grows in previously rural areas.
Centrifuges can save space, but combined with dryers and trucks for sludge transportation, both the expense and the greenhouse gas emissions start to pile up.
A Vibrating Membrane that Harvests Value from Wastewater
If you’re a regular reader of CleanTechnica, you can see where this is going. Over the years, we’ve spent a lot of virtual ink enthusing over the valuable goodies that can be harvested from the waste of people (you can even run a car on it), livestock, and cheese making, among other food and beverage operations, and now we can add olive wastewater to the list.
The challenge is to come up with a cost-effective means of separating out valuable products from wastewater. In olive processing, the problem with conventional filters is membrane fouling due to a high concentration of colloids (gooey gelatinous stuff).
Under those circumstances, pretreatment and other means of keeping the filtration membrane clean enough to operate efficiently can be more trouble than it’s worth, especially for small olive processing facilities.
New Logic’s Solution is called the Vibratory Shear Enhanced Process (VSEP). It’s a little more complex than the name implies, but basically it involves using torsional vibration to keep up a crossflow of liquid across the membrane, in order to keep colloids from accumulating on the surface.
With saving space in mind, the system actually consists of hundreds of stacked membranes. That enables it to pack about 1,400 square feet of membrane space into one module with a footprint of only four square feet.
According to New Logic, in addition to collecting dissolved and suspended solids the system yields “drinkable water” without the need for pretreatment, and it also recovers usable oils.
A More Sustainable Olive Industry
The University of California–Davis Olive Center has just received a Department of Agriculture grant that puts New Logic’s olive wastewater treatment technology in a framework of overall improvement for the California olive industry, in terms of both economic and environmental sustainability.
The UC Davis Olive Center is a public-private partnership that “seeks to do for olives what UC Davis did for wine.”
It launched in 2008 and has already established an impressive track record in all facets of the industry, from analyzing consumer tastes to coordinating with federal regulators and developing high-efficiency harvesting machines.
The Olive Center’s interest in New Logic is just one part of the overall goal of the new Department of Agriculture grant. The central goal of the project is to help the olive industry improve its bottom line by cutting wastewater volume by about 90 percent, while reaping more additional value from the crop especially in the form of nutritional supplements and pharmaceuticals.
For its part in the project, New Logic is donating a VSEP system along with technical support and training.
In other olive industry cleantech news, last year the California company Musco Family Olive Co. installed a carbon-neutral system using olive pits as renewable energy for wastewater treatment; and a solar powered, algae-based system for reclaiming olive washing water is under development in Europe,
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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. You can also follow her on Twitter @TinaMCasey and Google+.