'Three Times More Than Usual' Chuseok Trash... Do You Feel Guilty? [Reading Science]

Three Scientific Solutions: Recycling Resource Recovery, Decomposing Microorganisms, and Biodegradable Resin Development
Thorough Separation and Disposal is the First Step... "Residents of the Seoul Metropolitan Area Face Greater Urgency Considering Landfill Closure in 2025"

[Image source=Yonhap News]

[Asia Economy Reporter Kim Bong-su] A massive plastic island drifts in the Pacific Ocean, and animals are dying. Microplastics, fragmented into tiny pieces and floating around, threaten humanity like a time bomb. During Chuseok, enormous amounts of plastic waste, such as packaging materials, are generated from gift packages delivered to households. The COVID-19 pandemic has increased food delivery and online shopping by 20-30%, and the coffee culture that frequently uses disposable cups has spread, making the situation even worse.

About 100 years ago, when Staudinger first proposed the concept of polymers, marking the beginning of the plastic era, did anyone consider these side effects? At that time, the discovery of polymers like plastic was a great achievement that created a new civilization. However, now the very advantage of plastics?their extremely durable chemical structure?has become a significant disadvantage causing severe environmental pollution. Can the science and technology that created plastic also develop solutions to its side effects?

[Image source=Yonhap News]

◇ Eliminating Mountains of Waste Vinyl

Three main methods are being researched to solve the waste plastic problem: recycling through resource recovery, using decomposing microorganisms, and employing biodegradable resins. First, the waste vinyl resource recovery technology, which started in Korea over ten years ago, has been continuously developing. Current technology consumes a lot of energy but produces a small amount of oil. It can only operate once a day, and repeated heating and cooling cause significant energy loss. The equipment has a short lifespan, and the oil yield is only about 30-40%. Waste vinyl resource recovery is still insufficient for full-scale implementation.

This is why the new technology announced in February by Dr. Lee Kyung-hwan's research team at the Korea Institute of Energy Research has attracted attention. Dr. Lee's team developed a technology that produces about twice as much oil using less energy. The machine can operate continuously without the inconvenience of turning it off and on for raw material input and residue discharge. It stably produces oil at a constant reaction temperature using low energy, with a yield as high as 62%. The institute is currently conducting scale-up research for commercial production and plans to commercialize it by processing 10 tons per day in 2022. Annually, over 2 million tons of waste vinyl are discarded in Korea, with 70-80% simply incinerated, landfilled, or dumped, causing environmental pollution. The 2019 garbage mountain incident in Uiseong, Gyeongbuk, is a representative case. Some local governments, such as Gangwon and Incheon, have already achieved results by processing waste vinyl through resource recovery, managing waste and securing resources simultaneously.

◇ Searching for Decomposing Microorganisms

Another approach to solving the plastic problem is researching microorganisms in nature that "consume" plastic. Some may doubt such organisms exist, but they do. Recently, the Austrian Center of Industrial Biotechnology (ACIB) announced that it found microorganisms in cow rumens that decompose plastic. These microorganisms living in the cow's rumen were found to break down polyethylene terephthalate (PET), a synthetic polyester used in PET bottles and fibers. In June last year, Professor Kim Dae-hwan's research team at Daegu Gyeongbuk Institute of Science and Technology (DGIST) discovered that the larvae of the American superworm contain gut fluids that decompose polystyrene, a plastic material.

Scientific communities are intensifying efforts to find plastic-decomposing microorganisms. Only about 10% of microorganisms existing in nature have known functions to humans, while the remaining 90% remain unidentified. Recently, the Korea Research Institute of Chemical Technology developed a screening kit that can determine whether microorganisms decompose plastic within a week, as part of these efforts.

Using microorganisms to decompose plastic requires systems for mass production, distribution, and supply, so commercialization is still difficult. However, as plastic pollution worsens and climate change becomes more severe, the potential for future application is high. According to the Chemical Research Institute, foreign countries do not disclose their lists of plastic-decomposing microorganisms publicly, treating them as national assets and keeping them highly confidential.

◇ Let's Make Biodegradable Plastics

There is also an accelerating movement to make plastics themselves from biodegradable materials. A representative example is LG Chem, which recently invested 2.6 trillion won to build production facilities at its Daesan plant in Chungnam to produce eco-friendly materials such as biodegradable resins. SKC also announced on the 16th that it would develop easily decomposable plastic materials in collaboration with a Japanese company. Nowadays, companies must consider ESG (Environmental, Social, and Governance) management and technology development for survival, including exports.

Advanced technology development at the national level is also ongoing. Dr. Oh Dong-yeop's research team at the Korea Research Institute of Chemical Technology recently developed a plastic bag that is 100% biodegradable underground within six months. It was made from bio-plastic (PBS) with different properties tailored for various purposes. The production cost is low, and unlike other biodegradable plastic bags, it does not tear easily. By adding cellulose and chitosan extracted from wood pulp and crab shells, respectively, its tensile strength is doubled. It can also be processed into other materials such as clothing and shoes.

The plastic problem is not a distant issue. Residents of the Seoul metropolitan area must prioritize solving plastic and vinyl waste problems due to the scheduled closure of the metropolitan landfill site in 2025. Why not start by thoroughly sorting recyclable waste immediately after the Chuseok holiday?