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Displaying items by tag: recycling

Did you know that your morning cup of coffee contributes to six million tonnes of spent coffee grounds going to landfill every year? This does not have to be the fate of your caffeine addiction and there are many opportunities to up-cycle spent coffee grounds into valuable commodities.

From fresh fruit, to roasted bean, to used up grounds, coffee’s chemical composition offers a range of uses beyond making your daily brew.

Potential applications range from biofuels, to health products, and fertiliser for farms or your garden. So why are we throwing this precious product away?

The answer is that processing and production can be more complex than you might imagine – even when we’re talking about simply using coffee grounds in your garden. What’s more, many recycling initiatives to turn waste coffee into valuable commodities are still in their early stages.

When composted properly, coffee can be an excellent fertiliser. Author provided

You may have noticed that some cafes now offer free spent coffee grounds for customers to take home and use in the garden. In theory, this is a great initiative but the reality is that fresh coffee grounds are high in caffeine, chlorogenic acid and tannins that are beneficial to humans but toxic to plants.

The spent coffee must be detoxified by composting for a minimum of 98 days for plants to benefit from the potassium and nitrogen contained in the roasted beans. Without adequate composting, the benefits are scant (see below). So if you do take some coffee grounds home from your local cafe, make sure you compost them before sprinkling them on the veggie patch.

Parsley plants after 70 days in soil containing a) 21 days composted spent coffee; b) fresh spent coffee grounds; c) newspaper; d) soil only; and e) fertiliser. Brendan Janissen, unpublished experimental results. Author provided

The good news is that properly composted coffee grounds offer a cheap alternative to agro-industrial fertilisers, potentially helping urban communities become greener and more sustainable. Savvy businesses have begun processing coffee grounds on a commercial scale, turning them into nutrient-rich fertilisers or soil conditioners in convenient pellets for use in the garden.

The coffee berries before harvest. Author provided

But why stop there? A potentially even more valuable ingredient is the chlorogenic acid. Although toxic to plants, as mentioned above, chlorogenic acid has potential as a natural health supplement for humans, because of its antioxidant, anticancer and neuroprotective properties.

The whole coffee production process is abundant in chlorogenic acid, particularly in raw coffee beans. Chlorogenic acid conversion efficiency is even better from green coffee pulp, with a 50% recovery rate, compared with 19% for spent coffee grounds.

As undersized and imperfect beans are discarded at this raw stage, many businesses have seized the opportunity to market green coffee extracts as a weight loss product, although more research is needed to confirm this potential.

Roasted coffee beans ready for grinding. Author provided

The list doesn’t end there. Coffee waste can be used to create a diverse list of chemicals, including enzymes and hormones for digestion of common biological compounds and to improve plant growth; and feedstocks for high-end crops such as mushrooms. Coffee oil has even been trialled as a fuel for London buses.

The ConversationWith abundant waste supplies due to the popularity of coffee consumption, by recycling the byproducts, perhaps we can enjoy one of our favourite beverages without too much guilt.

Tien Huynh, Senior Lecturer in the School of Sciences, RMIT University

This article was originally published on The Conversation. Read the original article.

Published in STEP Matters 194

At the last Clean Up Day the largest number of items collected by far was beverage containers (about 30% of items). Here’s hoping this situation will show improvement since the Return and Earn, as the Container Deposit Scheme is now called, started on 1 December.

As at 4 February, over 65 million containers have been collected. Many of these would have been previously in council collections. Containers can be returned to receive 10 cents per container or the refund can be donated to a charity. The price of drinks has gone up of course, mostly by 15 cents.

Click here to find a collection point near you and for more information about the types of containers that can be returned. Currently there is one in Ku-ring-gai and five in Hornsby.

Published in STEP Matters 194

Australians buy more than 100 million litres of paint each year but around 5% of it ends up as waste, making paint and its packaging one of the biggest source of liquid waste into landfill. Paint contains chemicals such as volatile organic compounds and metals that can contaminate our groundwater and endanger human health. It is important to not put these items into your garbage bin.

Currently householders can take their leftover paint to collection centres set up every six months or so by local councils. Often the Clean Up Day is missed. Meanwhile the old paint tins accumulate in the storage sheds. The alternative is waste collection centres but they cost about $4.50 per litre tin, no matter how full.

A world first program, called Paintback, has been launched recently to offer professional and home painters an easy option for disposing of unwanted paint and packaging correctly. It expects to keep more than 45,000 tonnes out of landfill over the next five years.

To fund it, the paint manufacturers will add 15 cents a litre to the wholesale price of their products. There will be no further charge for anyone to dispose of paint at any designated collection point.

Paintback, a not-for-profit company, has ACCC regulatory approval to apply the waste levy and the support of Australian, state and territory governments. States and Territories have agreed to amend environmental regulations to allow trade painters to use the same scheme as DIY painters.

About 70 paint-specific collection points will be established over the next two years – starting with 12 in capital cities through a partnership with Cleanaway, which provides the expertise and a significant national footprint to collect and treat the waste paint and packaging. Existing council waste management centres also will be invited to participate.

The industry will fund research to find better uses for unwanted paint. Uses for waste paints could include extracting fossil fuels for energy consumption. The steel and plastic packaging is also recycled into new products.

Published in STEP Matters 186

Just before Christmas, NSW Premier, Mike Baird, and the Environment Minister, Rob Stokes, announced that the Government favoured the introduction of state-based container deposit legislation (CDL). They seem to favour the current proposal developed by the Boomerang Alliance. This involves the installation of reverse vending machines in shopping centres and public places where people can return drink containers and retrieve the 10 cent deposit included in the purchase price. Council kerbside recycling collections would continue to operate.

Published in STEP Matters 179

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