Because algae require a variety of organic nutrients, it is possible to use them in wastewater treatment. In fact, wastewater has a significantly higher content of individual amino acids that support growth of algae, and they have been shown to reduce the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in wastewater (Christenson and Sims, 2011).

10.4 FEED

A final important use of spent biomass is a feed—for plants as fertilizers but also for such aquatic animals as fish or even zooplankton. These two applications are discussed in further detail in this section.