The Growing Use of Bio-Solids
1 September 2017
In an article from Cincinnati.com, city officials have pitched a $65 million idea that would utilize human waste to fertilize farms. They have concluded that it was the best and cheapest option for replacing the Little Miami waste incinerator, which currently doesn’t meet federal environmental standards. This got us thinking- what are bio-solids and how can they be used on or off the farm?
The EPA defines bio solids as nutrient-rich organic materials resulting from the treatment of domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth. According to biosolids.com, there are some benefits for using bio-solids.
· Improve crop production.
· Reduce soil erosion and protect water quality.
· Enrich forest land.
· Provide economic incentives.
While farm operations can benefit from bio-solids, many other industries can as well, providing another potential revenue stream for operators.
On the Farm
Fair Oaks Farms, a dairy farm located in northwest Indiana has been putting the cow manure they collect to good use by turning it into fuel. Fair Oaks co-founder, Mike McCloskey, recycles the cows’ waste by turning tons of manure into an energy source as part of a goal to reduce his business’s greenhouse gas emissions. Fair Oaks Farms operates 12 family-run dairies which has a total of 36,000 cows. Only 1% of U.S. dairy farms have 2,500 or more cows thus classifying them as big agriculture. It’s economically possible for Fair Oaks to convert manure into fuel that runs their farms and powers a fleet of trucks. McCloskey is working hard to prove the industry wrong by tackling environmental problems of operating a big agriculture farm and still make a profit. Fair Oaks’ makes this happen with alleyways on either side of the bedding which makes it easier for the workers to gather the manure while the cows are being milked. Then the manure is separated from sand and dirt and deposited into the farm’s anaerobic digesters. Inside the tank the manure mixes with microbes for 21 days. This is replicating the process that takes place in a cow’s stomach and breaking down into compost-like material while releasing bio-gas, which is captured in pipes. 60% of that methane gas powers Fair Oaks, generating the electricity that runs the farms and digesters. The other 40% of the gas is used for their fleet trucks that are powered by compressed natural gas. Today there are 200 dairy farms that use digesters but no other farm has gone quite as far with it as Fair Oaks.
In the Air
In the aviation industry, United Airlines is taking the leap into using farm waste and oils derived from animal fats to generate fuel for their jets. By using bio-fuels, United Airlines will cut carbon pollution and reduce the high costs of jet fuel. United Airlines will be the country’s first domestic airline to fly regular passenger flights on alternative fuel, as reported by Fast Company. This past June, United Airlines invested $30 million in Fulcrum BioEnergy, the single largest investment in an alternative fuel company by a U.S. airline. United also agreed to take 90 million gallons of jet fuel from Fulcrum each year. Fulcrum is set to start construction on a facility outside Nevada, where garbage from the Reno and northern Nevada areas will be turned into jet fuel and diesel. The plant will process more than 200,000 tons of waste and convert it over to 10 million gallons of jet fuel. So far the United Airline flights fueled with bio-fuel are flying from Los Angeles to San Francisco with the potential for longer flights in the future.
In the City
Los Angeles has found a way to turn 4 million residents’ raw sewage waste into a profit. Hyperion Treatment Plant, the city’s largest and oldest wastewater treatment facility is the location where all of the city’s raw sewage is transported. From there the liquids and solids are separated and the liquids are then stored for 12 days in digesters that kill disease but keep good bacteria alive. After the bio-solids have been tested for viruses and heavy metals to meet the EPA regulations, it is then transported by truck to Green Acres Farm, a city-owned 4,600acre farm located in Bakersfield. They use the bio-solids as fertilizer to grow crops such as wheat, corn, alfalfa, oats, milo and sudangrass. After these crops are harvested they are then sold as feedstock to local dairies and the Los Angeles zoo. The crop revenues of over $3.5 million offset total farm costs and generated an additional $632,000 profit in 2014. Aside from the additional profit, this method is helping with the environment and cutting down on pollution in the city.
With the above examples of how bio-solids are being used, we don’t see it slowing down especially if it’s cutting costs, making a profit and helping the environment. What’s your take on bio-solids? Would you consider or are you currently using bio-solids on your operation? Click here to go to our forum and tell us what your thoughts are on the use of bio-solids.
EDIT: On February 8 Phys.org released this article that sheds light on engineered bacteria that can be used to convert agricultural waste to chemicals that can be used for many other products ranging from chicken feed to flavor enhancers in food.
Photos courtesy of http://www.lacitysan.org/, http://www.kcet.org/shows/socal_connected/stories/environment/treated-human-waste.html