In Vietnam, students build self-sorting trash bins to tackle waste

By integrating artificial intelligence (Al) and the Internet of Things (IoT), the DaNa Green smart trash bin can automatically sort waste while encouraging users to change their disposal habits, offering a new pathway toward a circular economy and smarter cities.

“We believe meaningful change can start with very small actions,” said Nguyen Viet Hoang, one of the innovators. 

"If each person is willing to dispose of waste properly, with the support of technology, cities can become cleaner and more liveable.”

From careless disposal to smart sorting

The DaNa Green invention team includes Nguyen Viet Hoang, Ho Ngoc Khanh Quynh, and Nguyen Ngoc Phuong Nhi from the Faculty of E-commerce at the University of Economics, University of Da Nang, alongside Hoang Le Anh Tuan and Chau Chi Hieu from the Faculty of Information Technology at the University of Science and Technology, University of Da Nang.

Hoang, the team leader, said the idea grew out of everyday observations.

“In many public spaces, waste-sorting bins are already in place with clear instructions, yet most people still throw trash into the wrong compartment,” he said.

“It’s not intentional, they often don’t know which category the waste belongs to, or they don’t want to spend extra time figuring it out.”

That reality, he added, reflects the broader challenges Vietnam faces in sorting household waste at the source.

From that problem, the students developed a project titled 'An AI- and IoT-Integrated Smart Waste Collection System,' known as DaNa Green, built on the idea that waste should be more than something to be discarded.

Team member Tuan said the bin is a rectangular unit about 1.2 meters high and nearly one meter long, with a width of 30-40 centimeters. 

It is divided into compartments for recyclable waste, such as plastic, paper and metal, and other waste.

When a user disposes of trash, an Al-powered camera scans the item, analyzes the image, and identifies the waste type. 

A motorized system then rotates to direct the waste into the correct compartment, a process that takes about one to one-and-a-half seconds.

The Al system is trained on real-world images of common recyclable waste and currently achieves an accuracy rate of about 90-95 percent, Tuan said.

Items that are rare or difficult to identify are automatically diverted to a separate compartment to minimize sorting errors.

In parallel, an IoT system integrates sensors to monitor how full each compartment is. 

When a bin is nearing capacity, data is automatically transmitted to a management platform, allowing waste collection units to proactively schedule pick-ups and prevent overflow or inefficient collection, he added.

Small incentives, big shifts for environment

Another distinguishing feature of DaNa Green is its incentive mechanism designed to encourage users to sort waste correctly. 

Each bin is equipped with a QR code displayed on a screen, allowing users to scan and accumulate points. 

Every time recyclable waste is disposed of properly, the system records reward points that can later be exchanged for small gifts such as reusable water bottles or environment-friendly products.

“We realized that relying on awareness alone is very difficult,” Hoang said. 

"But when there is an element of fun and a reward, especially for children, behaviour changes very clearly.”

Trial results suggest the approach has been effective. 

At an English language center where the bin was installed, many parents actively guided their children to dispose of waste correctly to earn points and redeem gifts. 

In the An Thuong pedestrian area, a busy hub for tourists and foreign visitors, many people expressed surprise and interest upon seeing the 'smart' bin, viewing it as a positive symbol of Da Nang’s ambition to become an environmentally-oriented city.

Nguyen Thi Minh Anh, a third-year student at the University of Economics, who has directly used the product on campus, said the bin was both novel and convenient. 

"We often hesitate to sort waste because we’re not sure which category it belongs to. Now the machine recognizes it automatically, and the fact that we can earn points and exchange gifts makes it more motivating,” she said, adding that wider deployment in schools could have strong educational benefits.

According to the project team, similar smart waste bins available globally typically cost between US$10,000 and $12,000. 

By contrast, the DaNa Green bin is estimated to cost about VND2-5 million ($80-200) at commercial scale, only slightly higher than a standard large-capacity plastic bin.

Hoang said the team’s biggest challenge was ensuring the technology remained affordable, durable, and suitable for local conditions. 

Limited funding, combined with the costs of hardware fabrication and real-world testing at multiple locations, posed significant constraints.

First prize in NEO-UP 2024 competition

Beyond a standalone product, DaNa Green aims to build a closed-loop system linking users, smart bins, waste collectors, and recycling businesses. 

Recyclable waste, once sorted, can be sold to recycling firms, with the proceeds used to sustain the reward scheme and system operations.

The project won first prize at the NEO-UP 2024 competition, reached the national finals of the Viet Future Innovation Awards 2024, and has received support from the Da Nang Business Incubator.