Plastic waste pollution is an urgent ecological threat, with the problem compounded by the use of disposable plastics during the COVID-19 pandemic, from plastic take-out containers to disposable medical supplies such as test swabs. Many remediation strategies have been employed to degrade plastic waste, and a new study published in Durability explored the use of insect species.
To study: Deworming the circular economy for bio-waste and plastics: Hermetia illucens, Tenebrio molitor and Zophobas morio. Image Credit: Teerasak Ladnongkhun/Shutterstock.com
A setback for plastic waste cleanup efforts
Although there has been progress in reducing the amount of plastic consumed in recent years, using alternative materials and increasing recycling efforts, the COVID-19 pandemic has caused a severe setback to these efforts. Plastic take-out containers, panic buying resulting in increased food waste, personal protective equipment, test kits and single-use medical swabs have all contributed to an exponential increase in plastic pollution in the environment .
The food market itself is expected to grow at a compound annual rate of 8.2% between 2020 and 2024, which is extremely detrimental to environmental stability in terms of food waste and plastic containers. Declining business and over-buying have contributed to increased food waste, both in restaurants and at home. All of this has pushed back the UN’s Sustainable Development Goals, particularly SDG 12, which aims to reduce food waste at retail and consumer level by 2030.
Even before the pandemic, 1.3 billion tons, or almost a third of the total food produced globally for human consumption, was wasted. Forty-nine million tonnes of plastic per year are used in Europe alone, 40% of which is used for packaging. Once in the environment, plastic waste does not biodegrade easily, causing huge landfill and marine pollution problems. Only 4% of plastic waste is currently recycled, and polythene bags and polystyrene cups take 500 years to degrade.
Burning plastic waste leads to increased carbon emissions. The problem is compounded by the decomposition of food waste, which releases methane, a potent greenhouse gas. Many recycling and remediation strategies have been proposed, including physical, chemical, and biological methods. Some of these strategies can be problematic in terms of cost, complexity, efficiency, and scalability.
Using insects for plastic waste remediation
Among biological remediation strategies, which include microbial colonies capable of breaking down complex organic and inorganic matter, insects have emerged as a potential alternative method. The new newspaper Durability explored the use of these biological organisms for plastic and food waste remediation strategies.
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The use of insects can potentially help achieve a zero waste circular economy. A zero waste approach aims to prevent waste from entering the environment, while a circular economy approach regenerates the environment, contributing to greater sustainability. A notable example of a circular zero waste strategy using a common species of insects is the use of cockroaches. With their insatiable appetites, they can quickly eliminate organic waste and are valuable food sources in some communities.
A better understanding of the etymology has led to the study of other insect species for the biological remediation of plastic and food waste. The two black soldiers fly (H. illucens) larvae, mealworms (in particular, T. molitor), and the super verses (Z. morio) have emerged as attractive candidates for this purpose.
H. illucens is well known as a species capable of efficiently degrading organic compounds and reproducing rapidly, with adult flies laying large numbers of eggs. Z. morio and T.molitor can feed on plastics, including polystyrene and polyethylene, which are the main components of plastic waste from the food industry. Using these species together will make it possible to design a self-contained natural solution for landfills and dumpsters to dispose of plastic waste contaminated with food waste.
Moreover, the authors stated that such a system would fit with the concept of circular economy. H, illucens can be used for the treatment of bio-waste with excrement as fertilizer. The insects can then be used as raw material for plants, animals and humans, as well as for the commercial extraction of compounds such as chitin for the medical industry and melanin for use as pigmentation.
The study published in Durability provided key research on insect bioremediation of food industry plastic waste, which is traditionally difficult to recycle and causes immense environmental damage when disposed of. In line with the United Nations Sustainable Development Goals and the concept of the circular economy, such a system would significantly reduce plastic and food waste and pollution issues and add value to waste streams, thereby facilitating a much more sustainable food industry at home. to come up.
Khuan, ZJ et al. (2022) Deworming the circular economy for bio-waste and plastics: Hermetia illucens, Tenebrio molitor and Zophobas morio [online] Durability 14(3)1594 | mdpi.com. Available at: https://www.mdpi.com/2071-1050/14/3/1594