Remediation of Heavy Metals in Contaminated Soil: A Review of Effects, Mechanisms and Strategies

Abstract

Contamination with heavy metals is a major problem that is increasing everywhere in the globe. This problem has drastically impacted the whole world including human and environmental health in the past 30 years. There are a number of strategies to remediate soil that is contaminated with heavy metals such as physical, biological and chemical, and these can be used individually and sometimes with one another to tackle this issue. Heavy metals such as lead (Pb) and arsenic (As) are often more effectively transmitted with the help of chemical and physical methods such as immobilization and soil cleaning due to low biological acid levels and strong soil binding. In contrast, metals such as cadmium (Cd) and zinc (Zn) are more mobile, and are suitable for biological approaches, including Phytoremediation & microbial therapy. Mercury (Hg) remains a challenge due to the conversion and complex transformations in environments to improve all methods. This review summarizes the toxic effects of heavy metal contaminated soil in different parts of earth. Microbes are used to change the concentration of heavy metals in soil to improve the ability of plants to grow in healthy way. This paper reviews about the mechanisms and strategies to remediate the contaminated soil. This paper discusses necessary technologies used for remediation of soil and also mentioning about the types and methods. There are so many microbes and plants that can be used as the best options for removing toxic heavy metals from soils because conventional and physical approaches can be expensive and ineffective in areas with low metal toxicity, where phytoremediation and bioremediation are considered as eco-friendly approaches.

Keywords: Soil, heavy metals, remediation, plants, microbes, contamination strategies, effects.