"The sorting system is really aimed at increasing the efficiency of recycling and reducing secondary pollution," Li said.

Guangzhou's garbage-sorting policy is believed to be the first of its kind among China's big cities. Beijing drafted a similar regulation in 2010 but isn't looking to enact it without further review.

Guangzhou, after adopting its sorting system, planned to ensure that at least 50 percent of its trash was sorted before being disposed of in a landfill or by other means, Li said.

But Huang Aihui, a Guangzhou resident, is worried about the efficiency of the system, saying it will be hard for many residents to get used to separating their trash into various categories in so short a time.