System turns manure into clean water

System turns manure into clean water

New technology can turn cow manure into clean water and extract nutrients from that water to serve as fertilizer.

NEW technology at Michigan State University is under development and near commercialization that can turn cow manure into clean water, extract nutrients from that water to serve as fertilizer and help solve the ever-present problem for animal agriculture of manure management.

Known as the McLanahan Nutrient Separation System, it takes an anaerobic digester and couples it with an ultrafiltration, air stripping and a reverse-osmosis system.

The result, or at least one of the results, is water that's clean enough for livestock to drink or, at the very least, to dispose of in an environmentally friendly manner.

"If you have 1,000 cows on your operation, they produce about 10 million gal. of manure a year," said Steve Safferman, an associate professor of biosystems and agricultural engineering who is involved in the project. "About 90% of the manure is water, but it contains large amounts of nutrients, carbon and pathogens that can have an environmental impact if not properly managed."

While turning the manure into clean water makes environmental sense, the team also is conducting research on how it can make good financial sense for farmers. In some cases, it could have a significant effect on the long-term viability of the farm.

"Here, in Michigan, we have a tendency to take water for granted, but out West, for example, where drought remains an issue, the accessibility of clean water could make the difference between a farm remaining viable or going out of business," Safferman said.

The process "goes beyond a typical digester," said Jim Wallace, a former Michigan State student who earned his doctorate under the direction of Safferman and William Bickert, a former professor of agricultural engineering. It does this by extracting nutrients from the manure that can be harmful to the environment and can be reused as fertilizer.

"For example, we're able to capture a large percentage of the ammonia that would otherwise be lost in the atmosphere. Ammonia is a negative from an air quality standpoint," said Wallace, who now works for McLanahan Corp., which is working to develop the technology.

Currently, the system produces about 50 gal. of water from 100 gal. of manure. Wallace said the goal is to increase that number to around 65 gal.

Work on the project began about 10 years ago under the direction of Bickert, who saw the potential of anaerobic digesting.

"It's a success story of a university project starting with a concept and moving all the way, hopefully, to commercial fruition," Safferman said.

It is hoped that the nutrient separation system will be ready for commercialization by the end of this year.


Biogas project award

Michigan State was also the recent recipient of the Institutional Biogas Project of the Year Award for the MSU South Campus Anaerobic Digester. The university received the award from the American Biogas Council for excelling in innovation, technology, collaboration and managing complex systems.

The anaerobic digestion facility generates approximately 3,000 megawatt-hours per year of renewable energy by processing organic waste from campus dining halls, food processing facilities and the Michigan State Dairy Farm. In addition to renewable energy for campus use, the facility also diverts nearly 10,000 tons per year of organic waste from landfills and wastewater treatment plants.

"It's an honor to receive this recognition. This is a unique project. It's one of the largest operating anaerobic digesters on a university campus," said Dana Kirk, manager of the Michigan State Anaerobic Digestion Research & Education Center.

Several companies were involved in building the digester, including technology provider Anaergia, engine supplier 2G Cenergy of Florida and contractor Weiland-Davco based in Lansing, Mich.


Low-fat products

Use of a unique strain of lactic acid bacteria may result in more palatable low-fat dairy products for consumers as well as a solution to an industry-wide problem for milk producers, according to Ashraf Hassan, associate professor of dairy science at South Dakota State University.

Low-fat products tend to have inferior texture and flavor because removing fat makes their structure rubbery, he explained. After examining bacteria from the dairy environment for more than 15 years, Hassan found a strain that mimics fat.

Hassan and doctoral student Nuria Garcia are refining an enzyme extracted from a unique bacterial strain that removes biofilms in dairy equipment. Garcia received a national award from the American Dairy Assn. for a poster on her biofilm research in 2013.

Some bacteria produce polysaccharides that can contain hundreds of sugar molecules, such as glucose, that are attached to one another. They bind significant amounts of water, according to Hassan.

The strain Hassan discovered produces polysaccharides with high water binding capacity that then improves the quality of low-fat dairy products.

"They give the same mouth feel (as fat) by increasing the thickness and giving smoothness," he added.

Hassan first used the bacteria to make low-fat cheese, which the nationally recognized South Dakota State dairy product judging team could not discern from regular high-fat cheese. The bacteria's patent-pending application has been licensed to a multinational dairy ingredient company.

That's only the beginning. The polysaccharide produced by this strain also improves the functionality of proteins recovered from the whey, a cheese byproduct, Hassan explained. This protein/polysaccharide mixture can be dried and added to salad dressing, mayonnaise or even processed meats like sausage. Its gelling properties will help make products that "firm quickly and have a much stronger body," he said.

Not only does this add value to the whey, but the mixture reduces manufacturing costs, Hassan said. When mixed with polysaccharide, less protein is needed to produce the same effect.

Furthermore, the polysaccharide produced by this strain minimizes the negative impact of heat on milk protein during pasteurization, according to Hassan. Essentially, heat breaks down protein, a process called denaturation, but the bacteria encapsulate the protein, thereby maintaining more of its nutritional value.

This unique polysaccharide will also address a long-standing problem in the dairy industry: the formation of biofilms on milk processing equipment, Hassan noted. Milk bacteria attach to contact surfaces and form colonies that can resist traditional cleaning methods. The bacteria Hassan identified interfere with the formation of these biofilms, possibly mitigating this industry-wide problem.

Because plaque is a classic case of biofilm developing on a person's teeth, this discovery may also translate into better human hygiene, according to Hassan. Eating yogurt made with these bacteria may help reduce plaque and prevent tooth decay.

To explore this possibility, Hassan is collaborating with a researcher from the University of Iowa School of Dentistry to apply for funding from the National Institutes of Health.


'Milk money'

June is Dairy Month, and this year, California dairy farmers and fluid milk processors are joining together to help local communities by supporting the Great American Milk Drive.

On a national level, this campaign, in conjunction with Feeding America, provides gallons of nutrient-rich milk for millions of families across the nation that are in need.

Closer to home, the Great American Milk Drive will enable local food banks to provide critical nourishment via milk to food-insecure families, especially during the summer months, when low-income children are out of school and unable to participate in school nutrition programs.

According to the Census Bureau, one in four Californians live in poverty, and more than 6.2 million experience food insecurity.

It's often hard for food banks to carry items that are perishable, like fluid milk. The California dairy industry, however, is standing behind an initiative that brings important protein to those who need it most, eliminating barriers at the food bank such as shelf-life or storage issues.

Thanks to consumer and industry donations, food banks will be able to provide their clients with vouchers that allow them to pick up milk at the local grocery store when they need it.

During the month of June, the California dairy industry will provide additional support by matching consumer donations in California dollar for dollar, up to $30,000. Dairy farmers, milk processors and nutrition professionals from around the state also will team up with local food banks for "Days of Service" in June to bring awareness to the issue of hunger and to celebrate their partnership.

Consumers can donate a gallon of milk or more by visiting the website By entering a ZIP code, the donation goes to a Feeding America food bank in the local community.

"As an industry, we are very concerned with giving all consumers access to healthy, nutritious products like milk. The Great American Milk Drive is close to the hearts and the core values of our dairy farm families who are part of local communities throughout the state," Jennifer Giambroni, director of communications at the California Milk Advisory Board, said on behalf of the three partnering organizations: the advisory board, the California Milk Processors Board and the Dairy Council of California.

Volume:86 Issue:23

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.