Heavy Metal Pollution Mitigation through Bioremediation: Innovations and Prospects

The heavy metals, which include cadmium, chromium, copper, lead, mercury, selenium, cobalt, nickel, zinc, and arsenic, pose a threat to ecosystems and human health as they are toxic, persist in the environment, and bioaccumulate. The entry of these metals into the environment occurs both due to natural processes, such as weathering of rocks and volcanism, as well as due to man-made processes such as mining, industrial effluents, and agricultural runoffs. They reduce agricultural productivity and soil health, and cause drastic health conditions, especially cancer and nerve disorders. Bioremediation is a sustainable and very cheap way of treating the environment as compared to conventional methods because it employs the use of microorganisms (e.g., Pseudomonas aeruginosa, Aspergillus niger), hyperaccumulator plants (e.g., Brassica juncea), and other advanced techniques. The current review focuses on metal-specific approaches of bioremediation, highlighting microbial-based bioremediation and phytoremediation together with newer bioremediation methods like nanotechnology, genetic engineering, bio-electrochemical systems, and artificial intelligence. High removal efficiencies are demonstrated through case studies such as the use of innovative techniques to eliminate heavy metal contamination in industrial sites. However, metal toxicity, environmental fluctuations, and constraints of genetically modified organisms limit scalability. Potential developments are the use of omics technologies and AI-based monitoring in combination with bio-electrochemical systems to increase efficiency and enable applicability in wider fields, which will assist in the sustainability of heavy metal pollution mitigation.