Polystyrene is a versatile plastic used in various products, including toys, electronics, and bean bag filling. But can polystyrene be recycled, and what role do superworms play in breaking it down? Let's explore.
Superworms: Nature's Polystyrene Recyclers?
While plastic is often considered non-biodegradable, new research suggests otherwise. Certain scavenger larvae, like superworms, can break down polystyrene into harmless byproducts, offering a potential solution to plastic pollution. Scientists have found that Zophobas atratus larvae can consume styrofoam as their sole diet, with gut bacteria converting it into minerals, energy, and carbon dioxide. This builds on previous findings that mealworms can also digest plastic.
Good News for Polystyrene Manufacturers
The discovery that superworms can eat polystyrene is encouraging for manufacturers. Polystyrene is a widely used plastic and a significant source of pollution. These worms harbor bacteria that can break down this material, offering hope for both the ecosystem and manufacturers. Zophobas atratus can digest polystyrene due to their evolutionary history, developing the ability to break down tough wood components.
How Superworms Break Down Polystyrene
In 2015, researchers found that mealworm beetles (Tenebrio Molitor) could degrade styrofoam using gut bacteria containing plastic-degrading enzymes. However, their small size limited their feeding rate. Scientists then investigated whether larger superworms (Zophobas atratus) with similar gut bacteria could be more effective.
The Superworm Experiment
Researchers divided superworms into two groups: one fed styrofoam and the other a natural diet. Over 28 days, the styrofoam group converted 36.7% of the polystyrene into carbon dioxide. Analysis revealed that gut bacteria broke down long polystyrene chains into smaller products. When the worms were given antibiotics to kill their gut flora, they could no longer derive energy from eating plastic.
The Future: Harvesting Bacteria for Polystyrene Recycling
The plan is to harvest these bacteria and use them to recycle polystyrene in special facilities or insert them into other insects for broader cleanup efforts. Researchers also aim to isolate bacterial enzymes for industrial-scale plastic degradation. This could lead to a biotech solution for plastic waste problems.
Impact on Superworm Health
Interestingly, superworms that eat polystyrene remain as healthy as those on a natural diet. Previous research found that mealworms could process flame retardant-laden styrofoam without harm, and shrimp fed these mealworms also thrived. This suggests that bacteria may be evolving the ability to digest plastics, offering a natural solution to plastic pollution.
Can Polystyrene Be Recycled? The Challenges
Polystyrene can be recycled, but it faces challenges. Curbside collection is rare due to the cost and logistical difficulties of building styrofoam-recycling machinery. Polystyrene recycling involves granulation, compacting, and densifying.
Polystyrene Recycling Processes: Granulation, Compacting, and Densification
Recycling polystyrene requires a three-step process:
- Granulation: Polystyrene waste is broken down into tiny beads using a granulator.
- Compacting: The granules are compressed into dense bales.
- Densification: Expanded polystyrene is shredded and exposed to high heat and pressure, forming a solid block that is then shredded into pellets.
Uses of Recycled Polystyrene
Recycled polystyrene pellets are used for storage, transport, packaging, refrigerator trays, toys, foam, and cups. They are also incorporated into plastic furniture and building materials like fence panels and roof tiles.
Logistical and Economic Challenges of Polystyrene Recycling
Polystyrene recycling is difficult due to logistical and economic reasons. Its bulky nature makes collection and transport challenging, and the machinery required is expensive. Polystyrene must also be free from flame retardants before processing, adding to the cost.
The Benefits of Polystyrene Recycling
Despite the challenges, polystyrene recycling is beneficial. Polystyrene production has relatively low carbon emissions compared to other plastics. Widespread recycling could significantly reduce environmental impact.
Superworms and the Future of Polystyrene Waste
The discovery that superworms can break down polystyrene is promising, given the difficulties in recycling it. In 2018, the world produced 359 million tonnes of polystyrene, but only 33 million tonnes were recycled. Superworms and other plastic-eating organisms offer a potential solution, turning plastics into harmless byproducts.
The Future of Plastic Waste Management
In the future, plastic-digesting bacteria could be inserted into more species or used in industrial processing, eliminating the need for traditional recycling. This could make plastic as "natural" as any other food source in the environment. For bean bag producers, these developments are encouraging, ensuring the continued use of state-of-the-art plastic-based fillings with natural methods to break them down.
