Iron (Fe) metal-organic frameworks: A new class of superior and sustainable phosphate adsorbents

To mitigate harmful algae blooms, chemicals are applied to the water that immobilize phosphate through adsorption. Metal-organic frameworks (MOFs) have recently emerged as a promising class of solid adsorbents for a wide variety of water pollutants, including phosphate. In the context of algae blooms however, limited knowledge exists regarding the performance of low-cost MOFs, their chemical stability in dilute phosphate concentrations and how they compare to other types of commonly used adsorbents. In this study, three iron based and low-cost MOFs were compared against commercial adsorbents in a relevant context. Overall, the MOFs exhibited a superior performance in terms of kinetics and adsorption capacity over a wide range of concentrations. The examination of the pore structure data revealed direct correlations with the adsorption kinetics. The comparison of the material cost and the adsorption capacity at ultra-low concentrations places these MOFs in a position to compete against commercial adsorbents. The exposure of the MOFs to dilute phosphate solutions resulted in negligible linker losses.

Automated summary

In order to mitigate harmful algae blooms, chemicals are used to immobilize phosphate in water. Recent studies have shown that metal-organic frameworks (MOFs) serve as efficient solid adsorbents for various water pollutants, including phosphate. This study compared the performance of low-cost MOFs with commercial adsorbents in the context of algae blooms, revealing that the MOFs exhibited superior adsorption kinetics and capacity over a wide concentration range. Additionally, the cost-effectiveness and minimal linker losses of the MOFs in dilute phosphate solutions position them as viable competitors to commercial adsorbents.