MAURO FERMARIELLO / SCIENCE PHOTO LIBRARY MAURO FERMARIELLO / SCIENCE PHOTO LIBRARY
Waste water treatment. This pool contains outgoing waste water from St. Mary's Hospital in Lacor, Gulu, Uganda. Algae is being used to treat the water, as it absorbs nitrates and phosphorus from the waste. Aerobic bacteria live in the water and on the roots of the plants, which convert the organic matter in the waste to carbon dioxide and other harmless chemicals.
Model release not required. Property release not required.