Beijing's primary and middle schools will get "reverse" vending machines, which pay out coins and stationary in exchange for empty bottles or used books, as part of efforts to boost recycling.

Thousands of the machines will be placed at more than 2,000 schools to ensure waste on campus is recycled and to avoid secondary pollution when the waste ends up in illegal underground workshops.

"More than 1.5 million students will benefit from the program and get into the habit of trash classification and recycling," said Li Yongkai from the Beijing Education Commission.