A staff worker cleans up trash beside an artificial floating island set in a reservoir for water purification in Beibei district of Chongqing Municipality, Southwest China, July 25, 2018.[Photo/Xinhua]

Aerial photo taken on July 25, 2018 shows artificial floating islands set in a river for water purification in Chaohu city, East China’s Anhui province. [Photo/Xinhua]

A staff worker cleans up trash beside an artificial floating island set in a reservoir for water purification in Beibei district of Chongqing Municipality, Southwest China, July 25, 2018.[Photo/Xinhua]