Microalgal Bioremediation: A Clean and Sustainable Approach for Controlling Environmental Pollution

Abstract

Environmental pollution is a major global threat today, with widespread consequences. Industrial effluents, flue gases, automobile emissions, solid waste, agricultural runoff, amongst others, have loaded air, water, and soil with a plethora of undesirable substances harmful for humans and their surroundings. Common pollutants, such as exhaust gases, heavy metals, pesticides, pharmaceuticals, and many emerging organic and inorganic chemicals, are causing multitude of chronic illnesses. With growing population and rapid industrialization, it is becoming increasingly important to develop efficient, cheap, sustainable, and scalable processes to mitigate these life-threatening pollutants. Conventional physiochemical methods used for the treatment of industrial, municipal, and agricultural wastewaters and emissions are effective, but they suffer serious drawbacks, such as sludge generation, membrane fouling, and high energy and reagent requirements. This has attracted the use of biological resources in development of sustainable and eco-friendly remediation processes. Microalgae particularly have emerged as a potential microorganism in bioremediation owing to their ability to adsorb, accumulate, and degrade many common pollutants using different mechanisms. Concomitant sequestration of carbon dioxide, generation of oxygen, and accumulation of lipids and carbohydrates with growth are however the real advantages of using microalgae in bioremediation. Moreover, simple and cheap nutritional and cultivation requirements of microalgae make it most suitable bioresource for mitigating pollution. The development of microalgae-based remediation processes is therefore an ambitious goal in environmental biotechnology. This chapter reviews important concepts, developments, challenges, and future prospects of microalgal bioremediation.