Efficiency of Algae for Heavy Metal Removal, Bioenergy Production, and Carbon Sequestration

Environmental contamination is one of the paramount concerns engulfing the entire world. Being nondegradable in nature, heavy metals (e.g., Ni, Cd, Cu, As, Hg, and Pb) are significant pollutants of soil and aquatic ecosystems. Although numerous technologies have been employed to remove toxic metals from contaminated sites, there is still need for more efficient and ecologically sound methods. The use of algal species for the removal of heavy metals as well as other contaminants like dyes, nutrients, ions etc. from water and wastewater, which is popularly known as phycoremediation, has been found to be eco-friendly, ecologically sound, and a value-added tool. The common algal species which are being used for phycoremediation are Chlorella, Scenedesmus, Oscillatoria, Lyngbya, Gloeocapsa, Spirulina, Chroococcus, Synechocystis, and Anabaena. The use of algae for the removal of pollutants also helps in carbon sequestration and biofuel production. This chapter discusses the removal of toxic metals from contaminated aquatic ecosystems using various species of micro- and macroalgae along with factors that influence the process of phycoremediation and the role of algae in biofuel production and carbon sequestration.