Is fermentation the food waste solution of the future?

09.07.2020 - 12:00
7. júlí 2020
 Mynd: Hrefna Björg Gylfadóttir
A world-first experiment started on Friday in Iceland to see if Bokashi composting can work as well on a municipal level as it does for individual households. Jarðgerðarfélagið is working on the project with the Rangárvallasýsla waste processing plant in southwest Iceland, and Landgræðslan (the Soil Conservation Service of Iceland).

The trial marks the first time the Bokashi method has been tried on an industrial scale to process organic waste from so many different homes, according to Björk Brynjarsdóttir, the founder of Jarðgerðarfélagið. The process works well and is increasingly popular on farms and individual households. 

The Bokashi process originated in Japan and works by mixing organic waste with a beneficial microculture and keeping it in an airtight container for six weeks. The benefits of the system are that almost no greenhouse gases are released as the food waste rots and the compost and nutrient-rich liquid are formed very quickly. The culture includes lactobacillus, photosynthetic bacteria, yeast, actinomycetes, and other bacteria. 

If successful, it is hoped the project will contribute to the fight against climate change. “We thought it was important to go out and start doing something ourselves,” Björk says. The project has benefitted from a grant from the special fund for female entrepreneurs. 

Jarðgerðarfélagið uses plastic fish containers for its airtight Bokashi processing. Usually when organic materials end in anaerobic conditions their decomposition results in significant methane emissions, which is why organic waste is an increasingly big headache for waste processing companies and municipalities around the world. Methane is a particularly potent greenhouse gas. 

Björk emphasises that what sets the Bokashi process aside is that it is quick and produces almost no greenhouse gases because the bacterial culture overrides the methanogens that produce methane, as well as other dangerous bacteria that cause disease. 

One challenge the project faces is that much of the organic waste has started to rot before it gets to the processing station, as organic waste is collected every fortnight. It is likely this can be overcome by adding more of the bacterial culture than might otherwise be used.  

Björk says she is excited to take measurements from the compost in six weeks’ time to see whether it will be safe and of high enough quality to use. She is also excited to see how well the maize-based biodegradable bags compost. Jarðgerðarfélagið and Landgræðslan will work together to establish whether and where the compost can be used to fertilise plants in Rangárvallasýsla. 

Local people have been good at separating their rubbish and not a lot of inorganic waste was found in the first tonne or two processed on Friday. Björk hopes that the compost created in the future can mostly be used locally in order to minimise transport costs and emissions. 

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Alexander Elliott
Project manager
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