Algal Bioremediation of heavy metals: An insight into removal mechanisms, recovery of by-products, challenges, and future opportunities

Abstract

Recently, modern techniques have gained attention for the remediation of heavy metals present in wastewater. Biological processes have been explored and employed as they have been proven to be sustainable, simple, and green. With the help of this review, we have tried to bring out knowledge on different microalgae strains used for the removal of heavy metals and their mechanism of action for the remediation. The removal of heavy metals is performed by microalgal species through different extracellular and intracellular mechanisms. Phycoremediation of heavy metal mechanisms has been discussed in detail. It is seen that alone bioremediation of heavy metals is not an economical strategy. Thus, efforts on the development of integrated systems of remediation have been increasing to make this process more economical and sustainable. This review further elaborates upon recent advancements in the remediation of heavy metals using microalgae. Along with this, challenges to phycoremediation of heavy metals and opportunities to overcome have been discussed which can make this process more efficient, economical, sustainable, and clean technology. Through the discussions in this review, it can be concluded that phycoremediation can play a significant role in remediation of heavy metals in a sustainable way along with realization of bioeconomic potential.

Keywords

• Phycoremediation
• Different types of mechanisms
• Algae tolerance for heavy metal
• Heavy metals
• Economical integrated set-up