Recent Advances in Heavy Metal Contamination and Removal Techniques: A Critical Review

Heavy metal contamination is a critical environmental issue that poses significant risks to human health, aquatic ecosystems, and agricultural productivity. Conventional removal techniques such as precipitation, coagulation, ion exchange, and adsorption have been widely employed, yet they often suffer from limitations, including inefficiency at low metal concentrations, high operational costs, and secondary waste generation. Recent advancements in nanotechnology, electrochemical methods, bioremediation, and hybrid treatment approaches have demonstrated enhanced removal efficiencies, selectivity, and sustainability. Nanomaterials, metal-organic frameworks (MOFs), and functionalized biochar offer high adsorption capacities, while electrocoagulation, electro-Fenton, and photocatalytic degradation present promising alternatives with reduced environmental impact. Additionally, microbial and phytoremediation-based strategies provide eco-friendly solutions but require optimization for large-scale applications. Despite these advancements, challenges remain in terms of scalability, economic feasibility, and regulatory compliance. Future research should focus on developing cost-effective, scalable nanomaterials, integrating hybrid treatment technologies, utilizing artificial intelligence for process optimization, and enhancing bioremediation efficiency through genetic engineering. Strengthening regulatory frameworks and promoting interdisciplinary collaborations will be crucial for the widespread adoption of sustainable heavy metal remediation technologies.