Plastics have revolutionized our everyday life, but the problems associated with them, such as segregation, chemical purity or recycling, present us with numerous challenges. The cooperation of scientists, producers and consumers will be crucial in solving these problems in order to reduce the negative impact of plastics on the environment.
One of the biggest challenges in recycling is proper separation and preparation of waste for further treatment. In the case of plastics, this is particularly difficult due to the diversity of their chemical composition and physical properties. In addition, distinguishing products by the type of material used is problematic for both average people and plastics specialists.
Each plastic is a combination of many polymers based on various chemical compounds and additives, such as dyes, fibers or other polymers. When a load of plastic waste arrives at a sorting plant, sorting it by type is very complicated. Currently, infrared technology (NIR) or density tests (swimming/drowning in water) are used for sorting, but they are not 100% accurate. For plastic to be recycled, it must be at least 96% pure in terms of polymer type.
Researchers at Aarhus University, working with Vestforbrænding, Dansk Affaldsminimering Aps and PLASTIX, have developed a new imaging technology that can distinguish between 12 different types of plastic. This technology uses a hyperspectral infrared camera and machine learning to analyze and categorize the type of material already on the conveyor belt in the sorting plant. In this way, different types of plastics can be separated, identifying the most common materials used in everyday products.
Unfortunately, even the best recycling technologies have their limitations. Researchers from Brunel University London have found that drinks bottled in recycled plastic bottles can contain up to 150 different chemicals, 18 of which were found in concentrations exceeding legal limits. This suggests that problems with the recycling process could lead to contamination of some bottled beverages. So-called food contact substances (FCCs) are commonly found in food and beverage packaging, and most are considered perfectly safe at low concentrations. Unfortunately, research by British scientists has shown that drinks bottled in recycled polyethylene terephthalate (PET) bottles may contain higher concentrations of FCC than drinks bottled in “virgin” PET.
The researchers point to several factors that can cause the FCC to be present in bottled beverages, including the production of empty bottles, but also the conditions under which bottles are filled, stored, distributed and displayed on shelves, such as when exposed to high levels of sunlight or humidity. To reduce the amount of chemicals found in bottled beverages, the study suggests the use of so-called “super-cleaning”, which consists in a three-stage process of cleaning old plastics before recycling – high-temperature washing, gas washing and chemical washing.
The report, published in the Journal of Hazardous Materials, also points out that recyclers need to improve the way they collect, sort and recycle PET bottles, and that bottle manufacturers should prioritize designing for recycling to improve the quality of recycled products. However, the ultimate solution is to stop using PET.
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FAQs
Due to lack of knowledge, different types of plastic are often combined in manufacturing processes, which makes recycling them much more difficult. This often leads to plastics being incinerated, which is a major waste of valuable resources.
What makes recycling plastics so difficult? ›
Different types of plastic don't mix well when they are melted down and small amounts of the wrong type can degrade the quality of a whole batch, so plastic has to be carefully sorted first. In high-income countries, this sorting usually happens with the help of high-tech machines at large-scale recycling facilities.
What is the real problem with the plastic recycling industry? ›
Plastic, which is made from oil and gas, is notoriously difficult to recycle. Doing so requires meticulous sorting, since most of the thousands of chemically distinct varieties of plastic cannot be recycled together. That renders an already pricey process even more expensive.
Why is plastic no longer recyclable? ›
"It's difficult to reprocess and sort through all the plastic," said Lisa Ramsden, Greenpeace USA Senior Plastics Campaigner. Mixed container recycling bins contain a lot of contaminates that make plastic unrecyclable, she added. "Recycling is not the problem, plastics are," Ramsden explained.
What are the downsides of recycling plastic? ›
The main drawback with mechanical recycling is that it changes the molecular structure of the plastic, in turn reducing its material integrity. As a result, recycled plastic is routinely mixed with virgin plastic to make new products, and even then, it can still only be recycled two or three times.
Which plastics are hardest to recycle? ›
Along with #6 PS (polystyrene) and black plastics, #3 PVC (polyvinyl chloride) and #7 PC (polycarbonate, not to be confused with #7 PLA, polylactic acid, which is a plant-based plastic) plastics are considered among the most toxic plastics to produce, and the most difficult to recycle.
What is the biggest problem with plastic waste? ›
Unlike other materials, plastic does not biodegrade. It can take up to 1,000 years to break down, so when it is discarded, it builds up in the environment until it reaches a crisis point. This pollution chokes marine wildlife, damages soil and poisons groundwater, and can cause serious health impacts.
What percentage of recycling actually gets recycled? ›
The Environmental Protection Agency (EPA) estimated that about 9% of all plastic waste was successfully recycled in 2018. Researchers at the National Renewable Energy Laboratory (NREL) estimated that approximately 5% of all plastic waste was recycled in 2019.
What are the threats of recycling plastic? ›
Plastic recycling technologies release hazardous chemicals and produce new, toxic chemicals, poisoning workers and communities and contaminating the environment and the food chain.
Which plastic cannot be recycled? ›
Examples of non-recyclable plastics include bioplastics, composite plastic, plastic-coated wrapping paper and polycarbonate. Well known non-recyclable plastics include cling film and blister packaging.
The biggest limit to recycling is that not all materials can be recycled and so materials can only be recycled a limited number of times due to degradation each time through the process. This degradation is referred to as downcycling. In addition, recycling poses a number of societal and ethical issues.
Which of the following is one of the challenges in plastics recycling? ›
One of the biggest challenges in recycling is proper separation and preparation of waste for further treatment. In the case of plastics, this is particularly difficult due to the diversity of their chemical composition and physical properties.
What is the main challenge in managing plastic waste? ›
A: India faces several challenges in implementing plastic waste management practices, including lack of awareness among the general public, inadequate infrastructure for waste segregation and recycling, limited resources for enforcing regulations, and the presence of a vast informal sector involved in plastic waste ...
What is the greatest challenge with plastic? ›
Plastic pollution is building up in our oceans, throughout our natural environment and even in the stomachs of our precious wildlife. While recycling efforts can make a difference, we can't completely recycle our way out of the plastic issue.
