Zirconium Based MOFs and Their Potential Use in Water Remediation: Current Achievements and Possibilities

Abstract

Water pollution and scarcity are two of the most serious problems humanity is currently facing. Therefore, it is important to develop effective and inexpensive technologies and treatments to remove key pollutants from water. Zr based Metal-Organic Frameworks (MOFs) are new materials with the potential to remove organic and inorganic pollutants. However, it is important to critically analyze their performance in laboratory trials to evaluate their scalability potential for wastewater treatment. This document presents a critical review of the most recent studies and advances regarding Zr based MOFs, specifically the UiO-66 and Ui-O67 MOFs and analogous materials. We found that, although these materials are effective at removing inorganic and organic pollutants in water, there are still available research opportunities and knowledge gaps that need to be addressed. There is a need to further understand the mechanisms involved in the removal process to be able to develop more effective materials and/or to determine the best operating conditions during its implementation. Variations in removal efficiencies between the same MOFs also call for a more detailed description of the synthesis, as well as a better characterization of the material. This is because small variations in the characteristics of MOFs lead to non-homogeneous results, making accurate predictions of their removal capacity more difficult to determine. Finally, there is a need to better understand the stability of Zr based MOFs, as well as their removal capacity and reusability in wastewater with competitive ions, at standard pH and temperature operating conditions.