Students huddled in anticipation at Hong Kong Science Park while they waited their turn to present their findings and inventions at the final judging of the Hong Kong Student Science Competition. Jointly organised by the Federation of Youth Groups, the Education Bureau and the Science Museum, the competition - now in its 17th year - was held on April 11.
Projects were divided into inventions and investigations. This year's winners were St Paul's Co-educational College and Heep Yunn School in the junior division, and Ju Ching Chu Secondary School (Yuen Long) and St Paul's Co-educational College in the senior division.
St Paul's Form Three junior team investigated the herb coriander, and its ability to remove lead from water.
It's clear the project was born from good intentions. Explaining the origins of the investigation, St Paul's student Jonathan Lo Tsz-hei said: "It all started with a news report. Then we found a paper on the subject, but there was no supporting data. So we decided to look into it ourselves."
His teammate Tiffany Chen Hong-kiu added: "We wanted to allow farmers to use our methods without relying on the government, so it had to be cheap and accessible. That meant we couldn't use technological or chemical means."
But just because it's low tech doesn't mean it was easy. Working with herbs in a lab environment came with its own unique challenges, as Sandra Leung Hoi-sze explained. "The different smells became an inside joke after four months of work," Sandra said. Tang Jun-ping added: "Classmates entering the lab and complaining about the smell of our work was quite the experience."
Heep Yunn's Hayli Chiu Ching-hei described the difficulties her group faced. They invented something to improve fencing practice at their school. Instead of paper targets, they wanted electronic targets.
"We wanted to switch to electronic targets, but we didn't know how to do computer programming. So we asked our teachers for help and learned Flash," said Hayli.
The rewards made the hard work worth it - as well as computer programming; they learned the importance of teamwork and communication.
The senior team from St Paul's conducted a practical investigation on the effect of household plants absorbing formaldehyde, and then compared the results with products that claim to absorb it, including bamboo charcoal and packs of commercial formaldehyde absorbers. The chemical is used in building materials and to produce many household products.
Karen Leung Sum-yi explained how they came up with the idea.
"The school was being renovated, so we did research into absorbing formaldehyde."
Joyee Au Yeung Ying-hei added: "We started by looking at our surroundings, like our school and homes. A formaldehyde detector found our homes all exceeded safety limits, except for the bathrooms."
Mavis Wong Hei-tung said finding the right plants wasn't easy.
"We asked construction workers about formaldehyde-absorbing plants. They suggested pineapples. We tested them and found that yes, they worked. But they would release it back into the air. We chose three different plants that were cheap and tough. Aloe vera was the most successful example," Mavis said.
Working with formaldehyde can be dangerous, said Yam Wai-shan. "We performed the experiments by putting the materials in a sealed box. Formaldehyde is volatile so we had to make sure it wouldn't leak."
Ju Ching Chu's senior group made an exhaust fan that removes pollutants from cooking fumes. The team broke their prototype when it was almost finished, and had to build another one.
But Simon Tang Man-chung said this wasn't even the biggest challenge. "The hardest part was research, making the product was easier." Simon shared another interesting fact about their machine. "We found an actual blacksmith to forge the main body of the fan."
In addition, Ju Ching Chu's project has been selected to represent Hong Kong in the International Sustainable World Energy, Engineering and Environment Project, an American science contest. The team will fly to Houston, Texas, to compete in May.