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What is in the waste bin?

The composition of your waste bin is greatly affected by the availability and convenience of sorting options. 

Understanding the factors that influence our waste disposal decisions is essential for enhancing circularity and material recovery.  

Therefore, we as researchers have been digging into your waste data to better understand it, and in this blog, we will share some of our findings.  

Authored by Cansu Birgen, Michaël Becidan & Tuva Grytli

Waste composition analysis

As part of CircWtE project, two articles were published on this topic with the goal of providing insights to help achieve a more circular waste management. 

In the first study, we explored the impact of collection and sorting systems. In 2021, 330 bins were analysed by Circular Values Cluster from 11 different areas. These bins represent waste from about 400 households. We wanted to know if the way we collect and sort our trash have an influence on the waste composition, and did the pandemic change our habits. 

Next, we investigated if where we live affects our trash, and how the sorting system influences the proportions of food waste found in the mixed wastebin. Does the fact that we live in a busy city or quiet village affect the way we sort? By studying waste from ten MSW (Municipal solid waste) companies in central Norway, going through more than ten tons of waste from 750000 people. 

Even though waste composition analysis provides valuable insights, thorough data assessment is required to gain an even deeper understanding.  

Collection Systems, availability, and sorting behaviour 

Findings from the two articles showed that: 

1. Separate collection systems reduce food waste in mixed bins 

Separate collection systems help reduce food waste in mixed waste bins. When people have a separate bin just for food waste, the amount (proportion) of food waste in the mixed waste bin goes down from 53% to 28%.  

2. Collection availability has a large effect 

Having a separate collection system has a bigger effect on the composition of the waste in the mixed waste bin than changes over time, or the effect of the COVID-19 pandemic, which was assumed to influence the composition, but the analysis showed otherwise. 

Furthermore, when there is a collection system right at the kerbside for glass and metal packaging, the amount of these materials in the mixed trash goes down by more than 50%. Having a central recycling point or a place for people to drop off their waste didn’t really help with sorting glass and metal. So, it is important that the collection system is easy to use. 

If the mixed waste bin is located above the ground or underground does not affect what is in the waste. 

Separate collection of recyclable fractions like food, glass and metal packaging increases the share of mixed waste in the mixed waste bin, in other words, correct sorting. 

3. Location doesn’t matter 

Our study found that whether you live in a town/village or a city does not really have an impact on how well people sort their waste. 

Other factors that influence sorting behaviour 

Although not assessed in the studies mentioned above, according to information obtained from our industrial partners, several factors play a role in influencing sorting behaviour related to waste.  

Effective communication between waste management authorities and the citizens is crucial. Clear information about waste disposal practices, recycling guidelines, and environmental impact can encourage good sorting behaviour.  

Furthermore, when citizens understand how waste is collected, and disposed of, they are more likely to participate in sorting efforts. Transparency fosters trust and encourages responsible waste handling.  

Finally, people’s perception of what happens to the waste after disposal can also affect their behaviour. If individuals believe that their efforts contribute to positive environmental outcomes (such as recycling or proper disposal), they are more likely to sort waste correctly. 

Waste management for a circular future 

To be able to optimize waste management for a circular future, it is crucial to assess all relevant factors and how they are related to each other.  

Understanding how these dynamics work is essential for policymakers and waste management authorities, to develop effective strategies to promote waste sorting and contribute to a circular economy. 

Do you want to dig deeper into the two articles? Find them here: 

Thanks to CIVAC for providing (most of) the data! 

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