[COVER STORY] Composting can save the world | Infrastructure news

With the disposal of organic waste under increasing control and scrutiny, finding on-site solutions will ensure a legally and environmentally compliant waste management system.

A recent study conducted by the CSIR showed that almost 60% of all waste that ends up in South African landfills is organic and biodegradable. This represents a significant loss of nutrients, that could be used for composting and soil fertilisation.

The CSIR research estimates that food waste costs South Africa roughly R61.5 billion every year – with a third of the 31 million tonnes of food produced annually going to waste. Gavin Heron, co-founder at Earth Probiotic, says food waste represents a complex South African challenge, which requires a “fast, easy and cost-effective” solution.

“Food waste is a major environmental, financial and health problem in South Africa, with a high CO2e emission footprint of 627 kg/tonne when landfilled; however, pending legislation will impact how food waste is managed,” says Heron.

Food waste is a major source of greenhouse gas emissions, producing gases like methane, carbon dioxide and nitrous oxide. Methane emissions alone account for 30% of global warming and if emissions from food waste were measured as a country, it would be the third largest emitter in the world, after the USA
and China.  

Heron asserts that in order to help mitigate the effects of organic waste on the environment, climate-positive solutions need to be quickly scalable, and:

  • fast to implement, thus not require extensive refitting or the building of expensive additional infrastructure
  • easy to implement, with low training and compliance requirements
  • zero or relatively low cost.
Of all the organic waste diversion technologies available, the only one that meets all three criteria is composting, says Heron.

“While recycling organic waste into compost has significant greenhouse gas emission reduction benefits, compost also has other important soil, diversity and carbon sequestration benefits.”

Compost also delivers ecological benefits that include boosting soil health, encouraging plant growth, reducing fertiliser use, and positively impacting on nitrous oxide emissions, while supporting biodiversity.

“We need to adopt a ‘carbon first’ way of thinking – and that includes reducing waste in the first instance.”

Revolutionising composting

Composting is the natural process of recycling organic matter into a valuable soil amendment that can enrich soil and help plants grow. Earth Probiotic Recycling Solutions has been operating in the food waste composting industry since 2010. The company initially offered home composting solutions and then expanded into commercial and industrial composting solutions.

Its on-site food waste composting solutions have been implemented across South Africa, Botswana, Namibia, Zambia and Mozambique. These solutions are environmentally sustainable – using little energy – and ensure that a waste management system is both legally and environmentally compliant.

The company’s latest offering, which is revolutionising on-site composting, was developed and manufactured in South Africa. First launched in 2017, the Earth Cycler is an automated IoT-connected in-vessel composter. An in-vessel composter is an enclosed system that automates the processing and conversion of organic waste to compost.

These are usually smaller systems that can easily fit into a waste area. Similar to the scalability of home composting, in-vessel composters can be easily installed at a large number of sites and require little investment in infrastructure.

Now with two variants, the Earth Cycler can process up to 5 000 kg and 10 000 kg of food waste per month. Both solutions require the addition of compostable packaging, contaminated paper, egg cartons and other low-value, high-
carbon materials.

The three key benefits of the Earth Recycler are:

  • It requires minimal energy use and can be powered by solar.
  • Its output is less than a third of the waste input, which reduces logistics costs if the output needs to be moved.
  • It weighs and reports on input and outputs, and thus provides a real-time view of waste volumes and the carbon impact of diverting that waste from landfill.
Heron asserts that out of the many benefits of the Earth Cycler, its energy-saving abilities are an important aspect of the machine.

“The energy component of the Earth Cycler is very important because it has an extremely low energy footprint and, as mentioned, can even run off solar. It’s also important to note that this machine makes rich compost that can be used in the environment – it is not just producing a dehydrated waste output.”

Built-in automation

The intelligent control system is programmed to mix on loading and turn to a specific timing cycle, so as to optimise composting throughput. Once the maximum load is reached, an indicator light will flash, showing that a discharge operation
is required.

Data and remote access enabled

With a mobile, wireless or wired data connection, the Earth Cycler can be remotely managed and controlled, software updated and performance measured from anywhere in the world.

Environmental impact reporting

The Earth Cycler measures all inputs and outputs and can generate online reports showing:

  • carbon footprint reduction versus landfill
  • landfill airspace saving
  • compost output
  • potential carbon trading value.
Processing capacity

All food waste can be processed – including cooked and uncooked meat, seafood, soft bones, dairy, eggshells and citrus – as well as waste paper/board, compostable packaging and food service items.

The Earth Cycler consumes 30 kWh/month and is thus suitable for energy-constrained environments. This low power utilisation also means that it can be connected to off-grid energy systems through an inverter.

“The Earth Cycler is a cost-effective, easy-to-use composting system for any, and all, entities looking to manage food waste in an environmentally responsible manner,” says Heron.

Importance of composting

“Home composting is one of the easiest things anyone can do. At its most basic, it is just an aerobic pile of garden waste that will gradually become compost. At a more sophisticated level, compost can be made using food waste with a bokashi system and a segmented compost-bin system. Of course, vermicomposting can also be used in combination, or alone, within a household composting operation,” says Heron.

Heron adds that composting on an individual level is also important because, according to the numbers, one million households composting 10 kilograms of organic waste per month would reduce CO2e emissions by more than 74 million kilograms each year.

“With the right incentives and education, millions of households across South Africa could be doing some form of composting where they live – starting today.”

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