Microalgae in aquatic environs: A sustainable approach for remediation of heavy metals and emerging contaminants

Water pollution has grown to be a grave concern in the world. Direct discharge of wastewater poses risks to the aquatic ecosystems by causing eutrophication and degrades their physico-chemical characteristics. Moreover, wastewater is mainly enriched with recalcitrant toxic substances that pose detrimental impacts on the receiving environments. Conventional treatment approaches are mostly applied to remove nuisance pollutants from aquatic systems but are expensive and inefficient. Exploring microalgae has been found to be an efficient and ecofriendly technique for purification of aquatic environs. Furthermore, microalgae can effectively remove N (90–98.4%), P (66%–98%), Pb (75%–100%), Zn (15.6–99.7%), Cr (52.54%–96%), Hg (77%–97%), Cu (45%–98%) and Cd (2–93.06%)from contaminated aquatic systems. Microalgae play a pivotal role in degrading the complex pesticides (α-endosulfan, lindane, isoproturon and glyphosate) and emerging concerned contaminants (triclosan, bisphenol A, 17α-ethinylestradiol, tramadol and diclofenac) in elegant manner from disturbed environs. Apart from toxic pollutant removal, microalgae produce biomass, thereby acts as the efficient source of additional products like biofuel, carbohydrates, lipids and proteins which can make phycoremediation more frugal and sustainable.