Mitigation of Industrial Flue Gases and Wastewaters Through Algal Biomass Cultivation: Processes and Perspectives

Global population growth, increase in product manufacturing facilities, and increasing CO2 emissions from enterprises have led to global warming. Another major concern is the severe environmental contamination caused by industrial wastewater. In order to combat these challenges, a global scientific endeavor has emerged to capture CO2 from the point sources and use it to produce algal biomass. The methods which are presently practiced to clean wastewater and flue gases are cost-intensive processes with significant operational expenditures. Therefore, effective methods to use flue gas while also treating wastewater are desperately needed to overcome this issue. Algae-mediated CO2 capture is a conceivable option, where algae are grown to a high biomass concentration by consuming the nutrients and organic matter provided by industrial flue gas and wastewater. The algal biorefinery can be made economically viable by installing large-scale facilities while simultaneously remediating wastewater and industrial flue gas. The need of the hour is to develop an integrated and smart approach for sequestering CO2, valorizing wastewater, and minimizing waste generation and production of value-added products. The innovative and smart approach of large-scale algal cultivation can be deployed to sequester flue gas CO2 released by point sources, such as thermal power plants and other fossil fuel–based industries while reducing the atmospheric concentrations of greenhouse gases. This chapter describes different aspects of algal farming for production of biofuels and value-added products while seeking its potential to mitigate the environmental threats posed by industrial flue gas and wastewater.