Jeremy Ayre

Algal cultivation for treating agricultural waste offers distinct advantages over conventional treatment options. These include the capacity for carbon dioxide capture and the potential reuse of nutrients through the production of valuable algal biomass. Piggery wastewater (WW) is of particular interest due to its characteristically extreme pollutant potential, typically exceeding concentration levels of other agricultural effluents, and a rich history of experimental work going back to the 1970s. The associated challenges and potential for success in this field also have important ramifications for the processing of many other agricultural, industrial, and commercial WWs. This review takes into account research involving raw effluent, the development of anaerobic digestate (AD) as the preferred first‐stage treatment approach, current challenges such as water conservation via minimizing dilution while coping with excessively high ammonia concentrations, and the potential for nutrient limitations such as phosphorous. Other aspects of algal cultivation such as the choice of photobioreactor and some of the relevant economic factors are also discussed.