Green Chemistry through a Bioplastic Project Using Local Organic Waste: Effects of STEM–Project-Based Learning on Students' Scientific Literacy and Environmental Awareness

Imagine the world of science as a giant, bustling kitchen. For a long time, this kitchen has been churning out plastic—those shiny, durable wrappers and bottles that never seem to go away. While they are great for holding your lunch, they are terrible for the planet, piling up in oceans and landfills like a mountain of uninvited guests that refuse to leave. Scientists have been trying to cook up a solution: "Green Chemistry." Think of this not as a new recipe, but as a new philosophy for the kitchen. Instead of using toxic ingredients or creating endless trash, Green Chemistry teaches you how to cook with nature's own leftovers, make things that break down safely, and ensure nothing goes to waste.

But knowing the philosophy isn't enough; you have to actually get your hands dirty. This is where "STEM-Project-Based Learning" comes in. If traditional school is like watching a chef on TV and memorizing the ingredients list, STEM-PjBL is handing you an apron and saying, "Go make a meal using only the scraps in the fridge." It's about solving real problems by mixing Science, Technology, Engineering, and Math together. The big question researchers have been asking is: Does this "hands-on" approach actually make students smarter about science and more caring about the planet, or is it just a fun distraction? This paper dives into that question, testing whether turning students into eco-chefs can change how they think and how they feel about the world.

The Big Experiment: Cooking Up Change

In a study set in the bustling classrooms of North Sumatra, Indonesia, a team of researchers decided to test this "eco-chef" theory. They gathered 121 high school students, splitting them into two groups to see what would happen. One group, the "Control Group," got the standard treatment: the teacher talked, the students listened, and they learned about chemistry from a book. The other group, the "Experimental Group," got the special treatment: a Green Chemistry project wrapped in STEM-Project-Based Learning.

Their mission? To turn local organic waste—think of things like empty fruit bunches from palm oil trees, shrimp shells, and used cooking oil—into biodegradable bioplastics. It was a real-world challenge: take the trash that usually ends up in a landfill and turn it into something useful and safe for the planet.

The Results: A Recipe for Success

The researchers wanted to know two things: Did the students learn more science? And did they care more about the environment? To find out, they gave the students tests before and after the project.

1. Smarter Scientists
When it came to scientific literacy—the ability to explain how things work, read evidence, and solve problems—the "eco-chef" students absolutely crushed it.

• The Numbers: Before the project, both groups were on equal footing, with the experimental group averaging a score of 47.3 and the control group at 47.8.
• The Aftermath: After the project, the control group (who just listened to lectures) improved to 71.5. But the experimental group? They skyrocketed to 83.1.
• The Verdict: Even after the researchers used a special statistical tool (ANCOVA) to make sure the groups started on a fair playing field, the difference was huge. The math showed a result of F = 41.86 with a p < .001, meaning this wasn't a fluke. The "effect size" was 0.26, which the researchers describe as a "large" impact. In plain English: The students who actually made the bioplastic understood the science much better than those who just read about it.

2. Caring Citizens
The study also looked at "environmental awareness," which is a mix of knowing about problems, worrying about them, promising to fix them, and actually doing something. They measured this in four ways: Awareness, Concern, Commitment, and Practice.

• The Numbers: The experimental group saw their scores jump from an average of 60.3 before the project to 82.6 after. The control group only went from 60.7 to 71.9.
• The Gain: The experimental group gained 22.3 points, which the researchers called a "High" level of improvement. The control group gained 11.2 points, a "Moderate" improvement.
• The Nuance: Interestingly, while students got really good at knowing about the problems (Awareness) and caring about them (Concern), the "Practice" score (actually doing the right thing every day) was still the lowest of the four. The researchers suggest that while the project made them want to help, turning that feeling into a daily habit might take more time than just one school project.

What This Means for the Future

The paper doesn't claim to have solved the plastic crisis single-handedly, but it does suggest something powerful. It shows that when you take chemistry out of the textbook and put it into a real-world project—like turning shrimp shells into plastic—you don't just get better test scores. You get students who are sharper thinkers and more environmentally conscious.

The researchers found that this approach works because it connects the dots. Instead of learning about "polymers" as a boring word in a chapter, students saw how those polymers could be made from waste in their own neighborhood. They had to design the process, measure the ingredients, and test if their creation actually worked. This "learning by doing" made the science stick and made the environmental mission personal.

While the study was limited to two schools in one region and lasted for a relatively short time (about four class sessions), the evidence is strong that this method is a winning recipe. It suggests that if we want to raise a generation that can fix the planet's problems, we shouldn't just tell them what the problems are. We should hand them the tools, give them the waste, and let them cook up the solutions.