Page 13 - Simplified Wastewater Treatment Fundamentals_Ponds and Lagoons PT1

Stabilization Ponds & Sludge Lagoons

Pond Biology

Ponds utilize nature to treat wastewater. The wastewater organics, coupled with the

sun, provides energy for algae growth.

Algae feeds on wastewater organics and nutrients. Winds contact the surface of the

Pond and can provide small amounts of oxygen. During the day algae

photosynthesizes sunlight to oxygen. At night algae consumes oxygen. As a result,

Ponds often include mechanical surface aerators designed to provide oxygen

during the day and night, so that oxygen levels in the Pond never get so low as to

stress the useful bacteria or create odors.

In time, dying algae and microorganisms settle to the bottom of the Pond forming

a sludge layer. In the absence of oxygen, the anaerobic bacteria digests sludge,

breaking down additional organics. The sun and temperature evaporate

wastewater reducing the volume of treated wastewater effluent.