Advances in biological methods for the sequestration of heavy metals from water bodies: A review

Pollution is a major concern of the modern era as it affects all the principal aspects of the environment, especially the hydrosphere. Pollution with heavy metals has unequivocally threatened aquatic bodies and organisms as these metals are persistent, non-biodegradable, and toxic. Heavy metals tend to accumulate in the environment and eventually in humans, which makes their efficient removal a topic of paramount importance. Treatment of metal-contaminated water can be done both via chemical and biological methods. Where remediation through conventional methods is expensive and generates a large amount of sludge, biological methods are favoured over older and prevalent chemical purification processes because they are cheaper and environment friendly. The present review attempts to summarise effective methods for the remediation of water contaminated with heavy metals. We concluded that in biological techniques, bio-sorption is among the most employed and successful mechanisms because of its high efficacy and eco-friendly nature.