Remediation of Heavy Metals from Contaminated Soil: State of the Art Review of Sources, Risk, Policies and Available Remediation Techniques

Soil is considered contaminated when some amendments or alterations have been made to its natural environment. Many major pollutants in soil, such as salts, chemicals, heavy metals (HMs), disease-causing agents, or radioactive elements, have an adverse effect on human health and the development of plants. Due to their bioaccumulation, persistence, and toxicity, HMs are regarded as the most risky contaminant presence in the atmosphere. From the soil, these toxicants are released into the groundwater and ultimately reach human beings. If these contamination-related issues are not detected, acknowledged, delimited, analyzed, and effectively resolved, they might constitute a major risk on human being as well as on the environment. The concentration of HMs has increased dramatically over the past 30 years. When it comes to selecting a remediation technique for polluted soil, significant attention is required. Physical, chemical, and biological process is commonly used as effective remediation solution for polluted soils. This work gives a complete overview of the in-situ application of different techniques used to remediate soil contaminated by HMs, as well as their limitations and environmental benefits, which is required for the advancement of an efficient remediation plan. The mechanisms, advantages, and disadvantages of some of the recent techniques generally cited as among the best-proven present methods for cleaning up HM-contaminated sites are discussed in detail. Cleanup of HM-contaminated soil is required in order to minimize the associated hazards, keep land resources readily accessible to farming, improve the availability of food, and decrease the tenure issues caused by changes in the way the land is used. The best-tested methods for removing HM contamination from locations are discussed with limitation of the technique.