Role of Microalgae in Wastewater Treatment and Their Role in Nutrient Recovery

Rapid industrialization and urbanization have led to extensive pollution of water resources leading to a crisis. Traditional wastewater treatment processes are used to remove both inorganic and organic substances present in wastewater. These primary treatments are mainly aimed at the removal of easily settled and oxidize the organic matters present in the water which results in generation of clean effluent; however, this water contains high amount of inorganic nitrogen and phosphorus which may lead to rapid eutrophication. Microalgae-based wastewater treatment process has many advantages that can meet the new demand and can be an eco-friendly option for improved tertiary wastewater treatment. This type of treatment can produce valuable biomass along with the removal of inorganic nitrogen and phosphorus required for algal growth. This chapter gives an overview of the microalgae used for wastewater treatment. The different types of physical and chemical properties of wastewater suitable for algal growth have been discussed in detail along with their ability of nutrient assimilation/removal and biomass productivity. The limitations of the microalgal treatment are also discussed to highlight the major drawbacks of the system along with the possible solution.