Florida school eliminates solid food disposal costs with 24 hr. liquid composting

March 12, 2018

PALM BEACH GARDENS, FL — Arthur I. Meyer Jewish Academy in Palm Beach Gardens, FL eliminated the cost of hauling solid food waste, instead committing it to an LFC (Liquid Food Composter) which reduces up to 200 lbs (90 kg) of solid food into drain-safe “grey water” every 24 hours. The switch saves the school $5000 a year through reduced disposal costs, paying for the LFC in less than two years. It also set an environmental example for students by cutting CO2 emissions by about 18 tons (16 tonnes) per year, while demonstrating the wonder of accelerated bio-digestion.

The Academy purchased the LFC-50 which is developed and manufactured by Power Knot LLC of San Jose, CA. The LFC uses a proprietary mixture of microbes and enzymes (Powerzyme™) to aerobically decompose food waste within 24 hours, free of odors. Infusions of hot and cold water and air accelerate the process.

The food solids are transformed into grey water that is safely disposed in municipal waste streams. Because the grey water is rich in nutrients, the school is contemplating using it to simultaneously irrigate and fertilize its garden.

Students at Meyer's Academy queue for their school lunch.

Daily food waste load varies

Lindsey Ilarraza, kitchen manager, says the LFC reduces about 300 lb (136 kg) of food waste into grey water weekly.

Lindsey Ilarraza, kitchen manager, says the LFC reduces about 300 lb (136 kg) of food waste into grey water weekly. “It’s definitely doing its job,” he said.

“The kitchen staff daily empties into the composter between 13 and 60 lb (6 and 27 kg) of food-prep waste plus leftovers cleared from the cafeteria tables. On a heavy prep day, more food-prep waste goes into the machine,” said Llarraza. “Some days can be as little as 13 lb (6 kg). Other days can go up to as much as 60 lb (27 kg) depending on what we are doing in the kitchen.”

“We load the machine periodically throughout the day,” said Ilarraza. “We start preparing meals in the kitchen around 6:30 a.m., and place bins at our workstations for the food waste. When we are done with the preparation, we dump the waste into the machine. After lunch, food waste from the cafeteria is emptied into the machine.”

“We used to take out the trash three or four times a day,” she continues. “Now, we empty our garbage cans once a day. That allows us to schedule fewer garbage pick-ups in a week- most of the time, only one.”

Diverting food waste from landfill benefits the environment by avoiding methane emissions. Anaerobic decomposition of food waste in a landfill emits methane, which is 84 times worse for the atmosphere than CO2. In the U.S., food waste is the largest part of garbage sent to landfills. Diverting it can significantly reduce greenhouse gas emissions.

LFC accelerates food decomposition

Inside the drum of the LFC reside Powerchips™, which are highly porous pieces of plastic occupying about a third of the volume of the drum. These Powerchips act as a medium for the Powerzyme (mixture of microorganisms and enzymes) to create a large surface area to accelerate the composting process. Inside the composter, an arm rotates slowly to thoroughly stir the waste food with the chips, water, and oxygen. The continuous process produces water, CO2, and heat to 108°F (42°C), further accelerating the process. The CO2 created during decomposition is part of the natural cycle of carbon generation from plants, which makes the process carbon neutral. As the waste gradually breaks down into liquid, the system automatically flushes it through a connection for gravity discharge into a sewer drain. A mesh screen collects non-organic contaminants that do not decompose.

System tracks and reports performance

Load cells under each corner of the bio-digester weigh the waste (to an accuracy of ±1%) that is added and digested, and software compiles data graphically and numerically on usage and waste digested. The results are displayed on the machine’s touch screen in hourly, daily, weekly, and monthly units.

“The computer touch screen shows how much food has gone into the machine,” Ilarraza said. “Last year, it recorded 9,000 lb (4,100 kg). It also indicates how much CO2 is being diverted from the landfill, which last year was 18 tons (16 tonnes).”

The touch screen also displays the discharge rate, from which the computer calculates how much more waste to add at any given time. The screen also indicates when to replenish the Powerzyme™ (typically once per year) and when to replace the Powerchips™ (typically once every three years).

While the Meyer Academy staff monitors the machine’s performance through the touch screen, Access Recycling Solutions, which leases the machine to the school, monitors remotely by smart phone and computer. The lessor keeps track of machine health and status, and monitors alarms should they occur.

Academy is environmentally conscious

Meyer Academy learned about the bio-digester in early 2016 and thought it would be a good addition because the school strives to be environmentally conscious and endeavours to lead by example. “We are big on teaching values to the children,” said Natalie Barak, director of advancement. “They learn about environmental responsibility, and they see that we are actually doing something about it.”

About Arthur I. Meyer Jewish Academy

Meyer Academy is a state-of-the-art Jewish community day school for Kindergarten through 8th-grade students. For over 40 years, Meyer Academy has provided a rigorous and relevant dual language curriculum in a warm and nurturing environment that serves to educate future community leaders. Meyer Academy is a Department of Education Exemplary High Performing Blue Ribbon School and an authorized International Baccalaureate World School.

For additional information, access https://www.meyerprep.org/