rolling hills of waste

The circular economy, a new age in recycling

26 June 2018
Repurposing industrial waste is a win-win engineering solution
New technologies developed by the University of Sydney’s Chemical and Biomolecular Engineers are creating usable products from industrial waste that benefit people and the environment while creating new income streams.

While not a new concept, a circular economy is one that has increasing benefits for economic and business models, society and the environment because of the growing challenges of Australian and global waste challenges and the need to find solutions.

A circular economy approach looks to reuse and recycle waste for material recovery, extending the life of products and delaying or eliminating the resulting waste. This is opposed to our predominantly linear economy in which resources are extracted, produced, distributed, consumed and then disposed of, largely in landfill.

Such a model has grown increasingly problematic as waste management processes struggle to accommodate the rising amount of industrial waste. A circular economy recognises the detrimental impact of waste to the environment, and calls for government, industries and communities to embrace a whole-systems-thinking approach to resource production. New methods would focus on prolonging the usability of our resources and re-using or regenerating valuable products out of the waste.

The University of Sydney’s Chemical and Biomolecular Engineering researchers are developing groundbreaking solutions to meet these ever-growing waste challenges.

Green cement from power production

Associate Professor Ali Abbas, a researcher in the Waste Transformation Research Hub has developed a cement blend which incorporates fly ash and carbon dioxide wastes from power plants into the cement mix. This locks in otherwise environmentally-harmful waste products which would otherwise be disposed of or distributed through the air and creates a new green building material to be used in the construction industry, prolonging the lifespan of the original by-product indefinitely.

Prof Ali Abbas with a sample of green cement

Associate Professor Ali Abbas with a sample of his 'green cement'

Weight loss vitamin K from fish-farming

At the Centre for Excellence in Advanced Food Enginomics, Dr Dale McClure is currently investigating ways to utilise wastewater left from intensive fish farming. This water is nutrient-rich, allowing microalgae to grow. Using this specialised type of algae, Dr McClure plans to produce high value compounds such as Vitamin K and the weight-loss pigment fucoxanthin. These compounds can be worth more than $10,000/kg to pharmaceutical and food industries, potentially providing Australian farmers with an entirely new source of revenue and giving value to fish farming waste.

Prof Ali Abbas with a sample of green cement

An orange a day to keep the cancer away

Bala Shammugasamy, a PhD candidate in the School of Chemical and Biomolecular Engineering, is researching the cancer preventative benefits of bioactive compounds found in citrus peel. Orange peels may seem like an unlikely source of waste, but Australia alone currently produces 480,000 tonnes of oranges each year, with 50% of the fruit’s weight ending up as waste after it has been juiced. Bala’s research has identified that citrus extract can have a very strong ‘cytostatic effect’, meaning it can prevent cancer cells from multiplying. The aim is to create a supplement which can be used as a chemo preventative agent to inhibit a relapse in cancer growth and improve remission with chemotherapy patients.

As our populations continue to grow, so too does our waste. By repurposing our waste as new products and enacting a circular economy approach within our industries, we can maximise our resources and minimise the negative impacts on the environment through effective waste management.

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