Wastewater Algae to Value-Added Products

Globally, treatment and management of wastewater are a serious challenge. Voluminous wastewaters are generated on a day-to-day basis that is being either partly treated or untreated finds its ways into surface and groundwater thus enriching the systems with nutrients, pollutants and pathogens. In purview of the increasing water scarcity, rapid water deterioration, higher primary productivity in surface waters due to nutrient enrichment, towering wastewater production and complications related to its treatment, the understanding of water footprint, underlying mechanisms of wastewater treatment and transformation of terrestrial nutrients into value-added products and various downstream processes for their recovery needs to be understood. In this context, the algal treatment systems not only provides a simple and economical solution to wastewater treatment but also aids in the production of many valued bio-based products like lipids as feedstock for biofuels, single-cell proteins, Omega 3 fatty acids, carotenoids as astaxanthin and b-Carotene. The present chapter throws light on various mechanisms and strategies of wastewater transformations into value-added products while evaluating the techno-economics and feasibility of such systems for assessing its potential to be a bio-based industry. Various strategies for algal species selection targeting specific wastewater pollutants grown either as natural population or as engineered consortia with numerous wastewater treatment approaches until the production of valorized biomass is being discussed. Lastly, key techno-economics, environmental challenges and the scope of wastewater transformations into bio-based products are enumerated.