Synergizing phytoremediation and geopolymerization: A sustainable waste-to-wealth approach for heavy metal-contaminated soils

Abstract

The complete eradication of heavy metal pollution in the environment remains an unattainable goal soon, due to relentless increase in industrialization and urbanization. Consequently, the need for innovative, cost-effective, and eco-friendly remediation strategies to address heavy metal contamination has led researchers towards phytoremediation, utilizing the natural ability of plants to absorb and accumulate heavy metals. However, there is a persistent challenge in ensuring that the heavy metal absorbed by the accumulating plants (phytoaccumultaors) do not return into the soil or cause secondary contamination. Therefore, there is an exigent need for techniques that could stabilize/immobilize the phytoaccumulated heavy metals. Geopolymerization emerges as a technique with a proven capability to stabilize/immobilize heavy metals within its stable, three-dimensional framework. This review provides a concise overview of the mechanisms and techniques of phytoremediation and geopolymerization, then introduces an innovative synergistic approach to overcome the limitations of phytoremediation. By integrating these techniques, the potential for stabilizing phytoaccumulated heavy metals is unveiled, paving the way for sustainable environmental management. While only one study to date has directly investigated the possibility of stabilizing phytoaccumulated metals with geopolymers, this intersection represents a promising and underexplored field in heavy metal pollution management. Herein, existing knowledge was synthesized with the aim to inspire further research into this critical area of environmental chemistry, providing a valuable resource for researchers dedicated to advancing sustainable remediation strategies for heavy metal-contaminated soils.

Keywords: Aluminosilicate source; Compressive strength; Molar ratio; Phytoaccumulator ash; Stabilization; Waste aggregates.