25 © Springer Nature Singapore Pte Ltd. 2020 P. K. Arora (ed.), Microbial Technology for Health and Environment, Microorganisms for Sustainability 22, https://doi.org/10.1007/978-981-15-2679-4_2 M. Thakur · S. Bajaal · N. Rana Shoolini Institute of Life Sciences and Business Management, Affliated to Himachal Pradesh University, Solan, Himachal Pradesh, India M. L. Verma (*) Centre for Chemistry and Biotechnology, Deakin University, Victoria, Australia Department of Biotechnology, School of Basic Sciences, Indian Institute of Information Technology, Una, Himachal Pradesh, India 2 Microalgal Technology: A Promising Tool for Wastewater Remediation Meenu Thakur, Sakshi Bajaal, Neha Rana, and Madan L. Verma Abstract Many species of microalgae have excellent ability to remove nitrogen, phospho- rus, heavy metals, pesticides, organic and inorganic compounds, and pathogens from wastewater. Microalgae species grow well in wastewater and may be used for treatment of municipal, industrial, agro-industrial, and livestock wastewaters. Furthermore, microalgae biomass is an excellent source of production of various valuable products. In this chapter, applications of microalgae for treatment of wastewater and production of valuable products are discussed. Keywords Phycoremediation · Microalgae · Wastewater · Bioenergy · Metabolites 2.1 Introduction Pollution is the major threat to our environment which has resulted from increased mushrooming of industries and more urbanization. It affects our ecosystems, fora, fauna, and human health worldwide by contaminating soil, water, and air. Pollution arises due to increased concentrations of unwanted and harmful substances as the results of anthropogenic activities. Most of organic and inorganic constituents have