Algal-Based Wastewater Treatment and Biorefinery

Abstract World population is expanding at a very fast pace and thus the human developmental activities such as construction, transportation, manufacturing of materials, and the requirement of energy. In order to fulfill the demand of population, industrial production houses are generating a huge amount of wastewater as an essential by-product and struggling hard to treat this water to an acceptable limit before it is discharged into environment. Untreated and improperly treated wastewater is a major cause of pollution of surface water bodies and groundwater. It results in environmental degradation causing loss of environmental health and productivity. Various physicochemical and biological methods are in practice to treat wastewater based on the nature and concentration of pollutants present in it. Biological treatment of wastewater facilitates reduction of biochemical oxygen demand, suspended solids and toxicity of industrial wastewaters, and production of low nutrient, environmentally benign outgoing effluent. Biorefinery based on algal biomass harvested on wastewater could be commercially viable and ecologically sustainable solution for eliminating grave threats of water pollution and global energy demand. From domestic to industrial, wastewater coming from every source has been exploited for the mass production of algal biomass for biofuel production as well as for nutrient removal. Algae have been established as an eco-friendly, economically sustainable, and inexhaustible source of lipid, carbohydrate, and protein along with many therapeutically active enzymes, pigments, sterols, and vitamins. Docosahexaenoic acids, eicosapentaenoic acid, astaxanthin, lutein, etc. are high-value low-volume products whose demand is increasing and getting preference over traditional animal origin due to their natural vegetative origin. This chapter presents an account on the application of microalgae for wastewater treatment, production of biofuels, and other by-products from the biomass produced as a result of bioremediation of wastewater.