The Challenges and Benefits of In-vessel Composting Our Food Waste and Catering Waste to Divert Material from Landfill and Provide Eden Project with a Valuable Fertiliser

As part of our Waste Neutral Programme, the Eden Project installed an in-vessel food waste composter, the ‘Neter 30’. This was developed by Torsten Hultin based on a smaller machine, the ‘Big Hannah’, many of which are in operation, predominantly in Scandinavia. Hultin promoted these composters to local communities and small businesses to provide food and other biodegradable waste recycling systems, producing a beneficial end product whilst fostering social responsibility towards waste.
Compliance with UK/EU legislation entailed shredding food waste going into the composting vessel. The resulting ‘paste’, consisting of much cooked waste, gave an acidic low temperature compost when mixed with recommended sawdust pellets. Experimentation under commercial operating conditions increased starting pH and achieved rapid high temperatures using a mixture of finished compost and card fluff as co-feedstocks whilst keeping moisture levels between 40-45%.
‘Neter 30’ compost can be used unamended as a growing medium or as a mulch. Containing high levels of N and K and reasonable levels of P, its real value is as a high nutrition additive to our green waste compost for use as a spring mulch to reduce our need for high N fertilisers. Work on this is ongoing but early results are very promising.