A colourful, framed painting of a tree may seem like an ordinary living room decoration, but after hearing about the special properties of this particular piece of art, homeowners may want to spare some space for it on the walls inside their houses.
Students have found a novel way to make new use of discarded durian husks. Thailand produces at least 300,000 tonnes of the husks a year.
Enterprising students from the Department of Environmental Engineering at King Mongkut's University of Technology Thon Buri (KMUTT) have found they can double as air purifiers.
The process involves burning the husks to make gas-absorbing charcoal, said Asst Prof Dr Patiya Kemacheevakul, a lecturer at the Environmental Engineering Department.
After being burnt, the durian husks shatter into small pieces, and can be used as material for artwork.
The husks' charcoaled form allows them to absorb harmful gases such as formaldehyde, a gas compound commonly found in household furniture such as wooden chairs and other lacquered or finished products.
The International Agency for Research on Cancer (IARC) classifies formaldehyde as a human carcinogen.
Ms Patiya, an adviser for the project, said students then used the charred husks to make three-dimensional paintings, which can serve as household decorations.
"In their plain form, durian husks do not look like they have much value," she said. "By turning them into art pieces, we can add value to what was originally considered waste."
In addition to the sheer amount of waste which durian consumption produces per year, the husks' rugged surface contains many pores that expand when they are charred, making them ideal for absorbing harmful gases, Ms Patiya said.
Other fruit husks and peels, such as those of mangosteens, can be used for the same purpose, since their peels also have pores that can absorb gases.
Asst Prof Surawut Chuangchote, a lecturer at the Department of Tool and Materials Engineering, another project adviser, said the process also involves coating the charred husks in a solution so they can be reused even after saturation.
The solution allows them to regenerate their gas-absorbing qualities upon being exposed to sunlight. Without the solution, the husks would only be able to absorb gases up to a point before they eventually need replacing, he said.
He said sunlight causes a reaction with the solution that can break down the gases absorbed by the charred husks, allowing the husks to regain their gas-absorbing properties.
Asst Prof Surawut said the project involved students making art of their own design which incorporated the charred durian husks coated in the catalysing solution.
Three Thai students, Chotiwat Jantarakasem, Patthranit Kunlasubpreedee and Danuwas Sarathana, received gold medal prizes for their projects at the 3rd World Invention Innovation Contest in Seoul, South Korea, in March.
Each of the students is currently pursuing further studies in environmental science, Mr Surawut said.
Ms Patthranit, currently enrolled at the Asian Institute of Technology (AIT), said she felt proud that her team's project was showcased internationally.
"This project could be beneficial overall for the public in several ways," she said. "It can serve as a method to decrease waste accumulated from durian husks at low cost, while providing health benefits for the public."
Graduate and postgraduate students from the programme are planning to pursue the project further. He said commercialising the creation of the art pieces is one option, and a group of graduate students have now established a company to oversee production of charred durian husk art pieces upon request, Asst Prof Surawut said.
"There are several possibilities to develop this project, since durian waste always piles up each year," Asst Prof Surawut said. "It would be great if these art pieces can be registered as Otop products in the future. The cost of one picture can even go below 100 baht," he said.
Visiting tourists could also be interested in the products upon learning about their durian-related origins and air-purifying qualities.
"The art pieces can come in different shapes and sizes, such as the one made by the students designed in the shape of a tree," he said.
"By retaining the texture of the durian's spikes, it could be a conversation-starter, doubling as an air-purification device."
