ABSTRACT
Photosynthesis is the process whereby organisms use solar energy to fix carbon dioxide (CO2) and obtain the reducing power to convert it to organic compounds. In wastewater ponds, the dominant photosynthetic organisms include algae, cyanobacteria, and purple sulfur bacteria (Pearson, 2005; Pipes, 1961). Photosynthesis may be classified as oxygenic or anoxygenic, depending on the source of reducing power used by a particular organism. In oxygenic photosynthesis, water serves as the source of reducing power, and O2 is a byproduct. The equation representing oxygenic photosynthesis is
H2O + Sunlight → 1/2O2 + 2H+ + 2e-(3.1)
Oxygenic photosynthetic algae and cyanobacteria convert CO2 to organic compounds, which serve as the major source of chemical energy for other aerobic organisms. Aerobic bacteria require the O2 produced to function in their role as primary consumers in degrading complex organic waste material.
