A truck collected unwanted textbooks from graduate students at a college in Zhengzhou in central China’s Henan Province. /CFP

The textbooks, used over the past four years, are being sold by weight. A set of books which cost 800 yuan (118 US dollars), went for less than 10 yuan (just over 1 US dollar) when sold by weight. /CFP

Some of the books are still new and covered in price tags. Students are now calling for a more environmentally-friendly way to recycle them. /CFP

"I know it is a big waste but these books do not mean anything to me after graduation. Shipping them home costs too much. So selling them is the best choice for others like me,” said one student who just sold his books. /CFP