Treating waste using biological methods is not new. Earthworms and black soldier flies have been used in decomposing organic materials. Recently, there is a research on treating plastic foam biologically!
The protagonists in the research are mealworms, the larvae of the Mealworm Beetle (Tenebrio molitor). Mealworms are rich in protein and commonly used as animal feed.
Plastic foam is artificially synthesised and not biodegradable. No animal normally feeds on plastic foam. The study found that with no other choice available, mealworms consume plastic foam. Half of the plastic foam consumed will be degraded into carbon dioxide, while some will be used for the growth of mealworms and the rest will be discharged from their bodies. The work of digesting is carried out by the microbes and enzymes in the mealworms' digestive tracts. The next step will be for the research team to identify these microbes and enzymes, and find out whether they can be cultivated by humans. This way, we can increase the efficiency of degrading plastic foam.
If the team succeeds, the plastic foam waste problem will be simplified. Yet it often takes at least a few years, sometimes even decades, for research results to be put to practical use. In recent years, several states in the United States decided to legislate against the use of plastic foam containers and the use of foam for transport, to reduce use of plastic foam at source.
In Hong Kong, some 90 tonnes of plastic foam are sent to the landfills each day; the volume is equivalent to 25 double-deck buses. Before legislation or a simple solution are in place, we must all work together to solve the plastic foam waste problem. For instance, you can bring your own food containers each time you order a takeaway!
Text | Helen Yau