Water Remediation to Water Mining: Cradle to Cradle in Wastewater Treatment Using Algae

Algal boom is a direct consequence of rampant eutrophication of water bodies. Presence of algae is considered objectionable as it leads to low dissolved oxygen level and decreased sunlight, thereby deteriorating the quality of water and adversely affecting aquatic flora and fauna. There has been a meticulous rate of research and development in the areas of application of algae, for the purpose of wastewater remediation and reuse. These efforts on the utilisation of algae have successfully brought algae into positive shades of limelight. Different technologies are being developed to utilize this biomass to the maximum extent in waste water remediation to solve the problems of algal disposal. Around 90–99% of removal has been achieved for toxic metals, harmful organic wastes and other inorganic matter in different types of wastewaters by using algae alone or a bio consortium of algae with other useful microspecies of bacteria and other plants. Algae in addition to proving as efficient substances in waste water remediation are also being explored for the recovery and recycling of several useful components. Along with remediation of wastewater; algae have also been found to be a suitable medium for mining or recovery of various metals and nutrients like phosphates and nitrates. Some recent studies have even shown adsorption of 25–30 mg/g for gold and uranium from wastewater by algal species like Galdieria sulphuraria and Hydrodictyon reticulatum. This chapter is an attempt to present the research carried out on the use of algae in the domain of wastewater remediation and mining.