Designing Receptacles to Promote Separation of Waste

As a growing population generates more waste, the world's landfills are rapidly filling. Poor waste management strategies can lead to contamination of nearby water or soil, disease transfer, and increased greenhouse gas emissions. A possible solution to this issue is source separation, which can reduce the amount of waste that ends up in landfills. Source separation refers to the practice of separating waste into different categories and containers when it is generated, so that certain types can be recycled or reused. However, educating people to sort their waste can be challenging. This study designed and advertised waste bins that looked like monsters and explored the impact of these bins on source separation.

This study took place in Chulalongkorn University in Thailand. Before designing the waste bins, the investigators analyzed the waste to determine the kinds of bins that were necessary. Interviews with fourth-year undergraduate students revealed that people may not use bins because of cleanliness or confusing signs. The investigators created three open bins that looked like monsters based on an architect's recommendations. Each monster had a background story about coming to earth to collect a certain waste, and these stories were promoted before the bins were deployed to make the separation practices easier to remember. The first monster bin was green, named Wetty, and meant for food scraps, food packaging, and snack bags. The second bin was blue, named Botty, and meant for plastic bottles and recyclable cans. The third bin was yellow, named Dryny, and meant for dry waste, such as paper.

The participants were 160 undergraduate students from the Department of Environmental Sciences. Participants included students ranging from first to fourth year, and the breakdown between males and females, as well as between students from different years in school, was representative of the student body. The investigators used posters, stickers, a video, and other advertising to launch the program and teach the undergraduates about the bins one week before the bins were set up. The bins were stationed in a high traffic and accessible location in the Department of Environmental Sciences for a month. Data were collected using observations and both pre- and post-bin-deployment questionnaires that measured knowledge, attitude, and satisfaction with the program; all students who participated completed this survey. Behavior was monitored by measuring the daily waste in bins during the last 2 weeks of the month-long program. The data were analyzed using statistical software.

Results showed that students exhibited high scores for attitude toward and knowledge of solid waste separation both before and after bin deployment, so there was no significant difference between pre- and post-program. Because students bought quick meals for convenient eating between classes, Wetty (the food waste bin) received the most waste and often overflowed. Students would put food-related items in the other bins sometimes, and there was also confusion about what was supposed to go in Botty (bottles and cans bin) and Dryny (dry waste bin), especially if food items included different components that should have been placed in multiple containers. Students reported that it was an interesting program, but their performance did not correspond to their knowledge and attitude.

This study had a number of limitations. This study took place in the Department of Environmental Sciences, where participants may have been more aware of recycling and waste concern. Students from other departments or schools may have less knowledge about these issues. The size and location of bins may have contributed to improper sorting of waste. Results may also vary in other locations or different cultures, and the results may not be the same with undergraduates in other countries.

Because students confirmed that the bin monsters were a novel and engaging way to boost waste separation, the author recommends that teams are created with both students and staff to promote behavior change and improve waste management further. In addition, the author felt that a fourth bin should also be added to collect unclean food packaging separately from compostable food waste. Media, signs, and posters should be clear, and signage should show photos of actual waste and how to separate it. The author also recommends increasing collection to reduce overflowing of bins and placing bins closest to the work rooms and on other floors as well.