Phytoremediation: An eco-friendly approach for remediation of heavy metal-contaminated soils-A comprehensive review

Abstract

The non-biodegradability of heavy metals makes them a serious environmental hazard. Heavy metal pollution in soil is caused by both natural and human activities. Such pollution impairs agricultural productivity and food security, interferes with microbial activity, and affects soil fertility. Research shows that Noccaea caerulescens has the capacity to accumulate up to 30,000 ppm, indicating the potential use of hyperaccumulators in metal remediation. Conventional methods of treating soils contaminated with heavy metals are frequently costly, time-consuming, and detrimental to the environment. Utilizing particular plant species to absorb and stabilize pollutants, phytoremediation is emerging as a successful and sustainable method. The numerous phytoremediation techniques and their uses in treating heavy metal-contaminated soils are thoroughly examined in this review, with an emphasis on the benefits, drawbacks, and potential for widespread application of each technique. Additionally, a comparative examination of several phytoremediation methods, including phytodegradation, rhizodegradation, phytostabilization, phytovolatilization, phytofiltration, and phytoextraction, showed a number of benefits in terms of affordability, user-friendliness, and environmental compatibility. This comprehensive review describes the variables that affect phytoremediation, such as plant physiology, metal speciation, soil pH, and climate. The field of nano-phytoremediation has explored opportunities to improve phytoremediation’s molecular efficiency. In numerous studies, the effectiveness of methods like phytostabilization, rhizodegradation, and phytovolatilization in lowering heavy metal concentrations has been demonstrated to reach up to 80 %. In order to increase phytoremediation’s effectiveness in addressing environmental pollution, this review emphasizes the significance of incorporating novel techniques and taking a variety of environmental factors into account.