From cardboard to caviar, closed-loop recycling

28 Oct From cardboard to caviar, closed-loop recycling

By Petz Scholtus

A bit like having found the philosopher’s stone, in Wakefield (UK) they are not turning metal into gold, but waste cardboard into caviar. It all started in 2002 with a research and development project called ABLE, initiated by the Green Business Network, to tackle various waste management problems and turn them into a lucrative closed-loop recycling scheme.

First there was cardboard, followed by a wormery
The initial problem was an excess of cardboard packaging waste, collected from local businesses, which needed to be prevented from going to landfill. The solution to recycling large amount of cardboard lay in shredding it in order to use it for animal bedding. A small enterprise was set up to house and operate the shredding machine, which was to supply the local Huddersfield Community Farm with bedding, giving job opportunities to socially disadvantaged people.

Later it was discovered that mixing the shredded cardboard waste with manure, it could be used very successfully for composting, adding value to the product. After the shredding facility was set up, the next step was to start a composting facility at Huddersfield Community Farm. A special wormery was built; a composting system where worms are added to create a richer compost.

The compost was then used to grow food for lunch at a nearby Therapeutic Centre. Another by-product that would later on serve to produce energy for the fish farm was the compost sludge. It would be used as fertilizer to grow willow, a local plant, which serves as biofuel when burned to heat the water in the fish tanks, avoiding the use of non-renewable energy. These first two links of the growing recycling chain, the recycling of cardboard and production of compost, already led to great benefits: They resulted in reducing the volumes of cardboard waste going to landfill, saving money for both local businesses and Huddersfield Community Farm, and, generated revenue from the sale of waste derived products such as compost, plant-food and worms for fishing.

How the sturgeon entered the scheme
The worms are in fact the next link in the recycling loop scheme of the ABLE project. Looking for a way to use the excess worms from the composting beds, the idea to produce fish that would feed on worms was born. An innovative fish tank system was build to grow Sturgeon, a slow-growing and therefore endangered fish specie. Most contemporary black caviar is roe from sturgeon fished from the Caspian Sea, which is suffering from over-fishing, pollution and loss of habitat. The sustainably grown sturgeon fed on the worms that in turn were fed on cardboard waste, is sold either as food for humans or kept to maturity for the production of caviar. Both the innovative technology aquaculture as well as vermiculture played an important role in closing the loop of this unusual recycling scheme, starting with cardboard and ending in caviar.

Eco-innovation at its finest As if turning cardboard into caviar and closing the recycling loop wasn’t enough, the ABLE project took the scheme a whole step further by adding educative activities. The project created for example a 3 km-long wildlife trail using a recycled glass substrate and recycle plastic tiles. A previously set up company by the Green Business Network manufactures these eco-friendly flooring solutions. The ABLE project also provided training and development of job skills in aquaculture, vermiculture, horticulture, land and countryside management for young disadvantaged people to help integrating them back into society. As a result, the ABLE project is an innovative closed-loop scheme, offering solutions such as efficient waste recycling, work opportunities for socially disadvantaged people, and energy from a renewable source, by linking new and existing local businesses together. The project won the