Microbial, Plant and Animal Based Strategies for Remediation of Heavy Metals: A Review

Abstract

Heavy metal contamination is a major environmental concern caused by industrialization, mining, agriculture, and urban activities. Toxic metals such as cadmium (Cd), lead (Pb), mercury (Hg), chromium (Cr), arsenic (As), and nickel (Ni) are persistent, non-biodegradable, and harmful to ecosystems and human health. Conventional remediation techniques are often expensive and may generate secondary pollution, prompting the need for sustainable alternatives. This review highlights microbial, plant, and animal-based strategies for heavy metal remediation. Microbial approaches employ bacteria, fungi, and algae that remove metals through biosorption, bioaccumulation, biotransformation, and redox processes. Phytoremediation uses plants, particularly hyperaccumulators, to extract, stabilize, or filter metals from contaminated soils and water. Animal-based methods, such as vermiremediation and aquatic bioindicators, also contribute to metal sequestration and ecological restoration. Integrated systems, including microbe-assisted phytoremediation and constructed wetlands, further enhance remediation efficiency.