Wastewater Treatment And Biomass Generation With Algae

The main breakthroughs in conventional biological nutrient removal technologies in wastewater treatment plants (WWTPs) over the past 15 years have resulted in improvements in the rates of nutrient removal and its associated energy costs. In this context, microalgae-based processes have emerged as a promising biotechnology platform for WWT based on its cost competitiveness and sustainability. The synergistic relationships between microalgae and bacteria support the simultaneous removal of C (organic and inorganic), N, and P via assimilation and dissimilatory mechanisms based on the complex interactions between autotrophic and heterotrophic metabolisms. In addition, microalgal photosynthesis can enhance the microbial oxidation of recalcitrant and toxic compounds, heavy metals, and pathogens while reducing the operating costs and environmental impacts associated with conventional mechanical aeration in activated sludge systems. This chapter presents a critical state-of-the-art review of the basis and applications of microalgae-based WWT and microalgal biomass valorization from an energy and environmental viewpoint.