Students make polluted water drinkable again
Source: Daily Yomiuri On Line
Takehiro Kusujima Yomiuri Shimbun Staff Writer
Tsutomu Kawahira, 18, is one of the three students from Miyako Agricultural High School on Miyakojima island, Okinawa Prefecture, who recently received the Stockholm Junior Water Prize, beating out students from 26 other countries.
"I want to protect the nature of the island I've inherited from my grandparents and ancestors," he said.
With no rivers on the island, islanders have to rely on underground sources for drinking water.
Eight years ago, students from the high school found that due to the use of chemical fertilizers by farmers, nitrate levels in groundwater on the island were close to limits defined in environmental standards, prompting the school to launch a research project to make the groundwater potable.
After finding that farming on the unique soil on the island required a lot of nitrates, students identified a bacteria capable of turning the offending substance into a nutrient.
They discovered that bagasse--the dry, fibrous residue remaining after sugarcane stalks are crushed to extract juice--could support the bacteria, and developed an organic fertilizer. About 200 farmers now use the fertilizer.
About 60 students of the school's environmental group participated in the research. "We won the award thanks to the research and experiments steadily carried out by students who have already graduated," Kawahira said.
He said he had learned that in other parts of the world, ecosystems were being destroyed by underground water pollution caused by nitrates, and that children had died after drinking polluted water despite the fact that they lived on beautiful islands with golden beaches and green sugarcane fields surrounded by blue seas.
"I love this island, which is friendly to people. I can't let it become uninhabitable," he said. He went to the agriculture school with the aim of taking over his family's flower shop, but he has a new goal now.
"I want to study environmental problems at university so I can help other people who are suffering," he said.