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ESF : Lasting leftovers: Graduate student develops system to transform food waste into agriculture

Leftover dining hall food will be turned into food for fish thanks to Michael Amadori.

Amadori, an environmental resources engineering graduate student at the State University of New York College of Environmental Science and Forestry, built an aquaponic system, which helps transform waste food to edible food.

‘We have a lot of waste products in our society, especially a lot of food waste in urban environments,’ Amadori said. ‘It’s going in your landfill, generating methane gas and contributing to global warming.’

The aquaponic system consists of four tanks with 15 to 17 tilapia fish in each. Fish in two of the tanks are fed commercial fish food, and fish from the other two are fed Amadori’s waste food pellets. The water and fish waste from the tanks are pumped up into beds of gravel, where lettuce grows. The plants and gravel act as a filter, allowing the water to be returned safely to the fish tanks, Amadori said.

The fish and lettuce can be both sold or consumed. The waste food pellets have comparable nutrient levels to the commercial fish food, but they are made out of different components, he said.



‘Commercial fish feed is made of three things — ground up fish, ground up corn, ground up vitamins,’ Amadori said. ‘It’s your Flintstone vitamins smashed up with some corn and fish.’

To make fish food out of waste food, Amadori said he separates dining hall waste into protein, carbohydrates and vegetables and combines them in certain ratios to meet the nutritional needs of the fish. He then forms the mixture into pellets and dries them.

Amadori said that while composting is a great method of waste reduction, the aquaponic system delivers results faster.

‘It’s a very quick turn around from waste to food to edible food,’ Amadori said.

Along with ensuring that the waste food pellets nourish the fish and plants as well as commercial food, Amadori said he is also trying to determine whether it is more economical to use waste food. If the economic feasibility can be proven, Amadori said, the concept of aquaponic systems could be easily implemented in urban areas because a lot of food can be produced in a small space.

Doug Daley, an environmental resources engineering professor, said he and Amadori came up with the aquaponic project after brainstorming what could be implemented in the time Amadori has left before graduating.

‘These systems are cropping up all over the place and are looked at from a horticultural or food science perspective,’ Daley said. ‘The fish food and the fish are providing nitrogen, phosphorus and other minerals that the plants need to grow.’

In a nonresearch situation, the lettuce will provide most of the revenue for the system because it can be harvested every few weeks as opposed to the fish, which can take up to a year before they are ready for consumption, Daley said. While making fish food from scrap food is cheaper than buying commercial food, the effort involved must also be taken into consideration, Daley said.

‘It’s cheaper to make your own bread, but most people don’t do that,’ he said.

Amadori’s work was featured in the Syracuse University showcase by Kevin Phu, a senior chemistry major who entered the aquaponic system and still helps with research.

Phu became involved with Amadori’s research after hearing him talk about his aquaponic system at the ESF Annual Fund, where they both worked.

‘Aquaponics was already an interest of mine, and I was more than happy to be a part of his research,’ Phu said.

Phu’s responsibilities include recording measurements and making fish pellets from scrap food. He said he is currently looking into nitrification rates for his senior thesis and hopes to use the system for future research.

‘Aquaponics is perhaps the most efficient use of water supply when it comes to producing food, a resource that is becoming less accessible,’ Phu said.

Phu said this type of aquaponic system could be implemented on a large scale and be economically viable — and in some places, it already is. During the summer he worked with Growing Power Inc., which has a system that features 10,000-gallon tanks that produce thousands of tilapia and yellow perch.

Said Phu: ‘I’ve worked on large scale systems that turn a profit and can be competitive with conventional fisheries.’

jlsiart@syr.edu





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