Removal of heavy metals from contaminated water using Metal-Organic Frameworks (MOFs): A review on techniques and applications

Abstract

One of the major environmental issues is the discharge of wastewater containing high concentrations of heavy metals (HMs), which harm humans and ecosystems. There are various methods for treating such wastes, among which adsorption has proven to be the most successful and economical approach. However, selecting an appropriate adsorbent depends on its chemical functionality, high surface area, porosity, and ability to target the pollutants (in our case, HMs). This study investigates the synthesis process and adsorption mechanism of metal–organic frameworks (MOFs) compounds. It also evaluates their effectiveness in removing common heavy metals, including lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr) from aqueous solutions. Furthermore, we analyze the comparable adsorption capacity of different MOFs for heavy metals and correlate it with the structural advantages that enable this capacity. Among MOFs, the zirconium-based ones have received special attention due to their excellent stability and adsorption efficiency, making them ideal for various water treatment processes. This report explored the future possibilities of MOF materials for environmental remediation. Findings showed that MOFs, particularly those based on zirconium, outperform standard adsorbents in terms of HMs removal from water due to their adjustable structure and high adsorption efficiency. It also provides a comparative examination of many MOFs and proposes numerous essential adsorption mechanisms that can be extremely useful in the future development of water treatment technologies.