[Photo provided to China Daily]

There are about 40 items available for exchange at the office. The school, with donations from society, invested about 20,000 yuan ($3,000) in the program.

"We'd pick up garbage such as water bottles along our way between home and school, and also bring garbage from home to school for exchange," says Nyima Dbangmo, who stays in a dorm during the weekdays and goes home on weekends.

Nyima Dbangmo says both of her parents and even her younger brother have joined the project by collecting garbage for her.

"It's hard to find enough garbage for exchange now."

It takes her about one month to "save up" enough waste bottles to get something like a notebook, she says. The boy students sometimes work together and wait for a long time in order to get larger items, such as soccer balls and basketballs.