dirty sewage and household rubbish in small river, irrigation channel causes rapid growth of algae. water pollution. ecological pr

algae and background beauty body bottle causes channel color course danger dangerous detail dirt dirty disaster drain ecological ecology environment forbidden full garbage green growth horizontal household humid industrial irrigation lake landscape leaves light marsh nature ocean oil outdoors park plant plastic plastics pollution pond problem rapid river rubbish scum sewage slime small spot spring summer surface swamp tank texture use waste water wheel