This is a scientific review article from the Journal of Environmental Chemical Engineering, published by Elsevier in 2022. It examines how Metal-Organic Frameworks (MOFs) can be used to remove heavy metals from water and wastewater. The document is written for researchers, environmental engineers, and water treatment professionals. It covers the problem of heavy metal pollution, compares…
This document is a peer-reviewed scientific review article published in the Journal of Environmental Chemical Engineering in 2022. It is written for researchers, environmental engineers, and water treatment professionals who study or develop methods for removing heavy metals from contaminated water. The review focuses on Metal-Organic Frameworks (MOFs) as a new class of adsorbent materials.
The article begins by explaining the global problem of heavy metal pollution in surface water and groundwater. It lists toxic metals such as lead, mercury, arsenic, cadmium, copper, chromium, and boron, and describes their harmful effects on human health and the environment. The introduction also covers natural and industrial sources of heavy metal contamination.
The review then compares existing treatment technologies, including ion exchange, precipitation, membrane processes, and adsorption. It discusses the advantages and disadvantages of each method, noting that adsorption is widely used due to its simplicity, effectiveness, and economic value. A table compares adsorption, precipitation, membrane, and ion exchange separation processes.
The core of the document focuses on adsorption as the preferred technique. It explains the physical and chemical adsorption mechanisms, including van der Waals forces and chemical bond formation. The text also discusses factors that affect adsorption efficiency, such as pH, temperature, contact time, and the nature of the adsorbent and contaminant.
The review evaluates various MOF types, including plain, modified, and magnetic MOF composites, for their ability to remove heavy metals. It reports adsorption capacity values ranging from a few to several hundred milligrams per gram. The document also covers MOF synthesis methods, including hydrothermal, sonochemical, microwave, and chemical approaches.
The final sections analyze the mechanisms governing adsorption and critically compare MOFs with existing technologies. The review aims to gather available knowledge on heavy metals adsorption by MOFs and serve as a guide for developing new MOFs or further applications of adsorption in water treatment.