A-dressing the problem
A university in the US has given 4 700 litres of ruined mayonnaise a dressing down – and fuelled a farm in the process. Last December, when freezing temperatures compromised 500 containers of mayonnaise in the canteen, Michigan State University had to find a use for it. After “students in the cafeteria complained” and the local food bank turned it down, the mayonnaise needed to be dealt with, wrote The State News. So Carla Iansiti, a school sustainability officer, dreamt up a plan – the condiment was fed to the university’s anaerobic digester, which is used to power some farms nearby. In the digester, microorganisms eat biodegradable waste and produce biogas, which can be combusted into heat and electricity. Iansiti correctly believed that the tiny creatures that thrive on sugar and fats would love mayonnaise. The university’s culinary services sustainability officer, Cole Gude, said: “It was a perfect situation to turn what could have been a catastrophe into something positive.” Biogas is naturally produced in landfill sites as bacteria break down our rubbish, but normally the methane escapes into the atmosphere, where it contributes to global warming. If a pipe network with holes in it is built into the landfill site and the methane is prevented from escaping, the methane can be collected and used.
– Atlas Obscura; BBC