Aerial photo taken on June 27, 2019 shows staff members of Chongqing Environment & Sanitation Group putting the sorted perishable garbage on a transport vehicle at a community in Jiulongpo District in Chongqing, southwest China. Chongqing has been striving to promote garbage sorting in recent years. A garbage classification system has covered 680,000 households from 1,796 communities of 39 streets and towns in the downtown area of Chongqing. (Xinhua/Liu Chan)

A resident puts sorted household waste into a garbage can at a community in Jiulongpo District in Chongqing, southwest China, June 27, 2019. Chongqing has been striving to promote garbage sorting in recent years. A garbage classification system has covered 680,000 households from 1,796 communities of 39 streets and towns in the downtown area of Chongqing. (Xinhua/Liu Chan)

Garbage classification inspector of Chongqing Environment & Sanitation Group Lu Xing (L) instructs a resident to redeem commodities with points earned from garbage classification at a community in Jiulongpo District in Chongqing, southwest China, June 27, 2019. Chongqing has been striving to promote garbage sorting in recent years. A garbage classification system has covered 680,000 households from 1,796 communities of 39 streets and towns in the downtown area of Chongqing. (Xinhua/Liu Chan)

Special transport vehicles full of waste are seen at a waste disposal plant of Chongqing Environment & Sanitation Group in Chongqing, southwest China, June 27, 2019.(Xinhua/Liu Chan)

A staff member checks the data on the instrument at a waste disposal plant of Chongqing Environment & Sanitation Group in Chongqing, southwest China, June 27, 2019. (Xinhua/Liu Chan)