Microbial, Plant and Animal Based Strategies for Remediation of Heavy Metals: A Review
Saroj Bala *
Department of Botany, Government P.G. College for Women, Sector 14, Panchkula-134109 (Haryana), India.
Rakhi
Department of Zoology, Government P.G. College for Women, Sector 14, Panchkula-134109 (Haryana), India.
Indu Mehra
Department of Botany, Sant Shiromani Shri Sain Bhagat Government College, Jind-126102 (Haryana), India.
Ranjan Singh
Department of Microbiology, Dr. Rammanohar Lohia Avadh University, Ayodhya-224001, (Uttar Pradesh), India.
*Author to whom correspondence should be addressed.
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.
Keywords: Heavy metal contamination, microbial remediation, phytoremediation, zooremediation, biotransformation, vermiremediation, plant–microbe interactions, sustainable remediation