화학공학소재연구정보센터
Process Safety and Environmental Protection, Vol.143, 322-331, 2020
Tuning the structure flexibility of metal-organic frameworks via adjusting precursor anionic species for selective removal of phosphorus
This study proposes a new strategy for manufacturing metal-organic frameworks (MOFs) with respective topologies and properties by adjusting the anionic species in the precursor solution. Three MOFs (e.g. Fe/Al (Cl-), Fe/Al (NO3-) and Fe/Al (SO42-)) were successfully synthesized and used for removal of phosphate from water. Surprisingly, when chlorinated salt was used as the precursor, only Al was detected in the Fe/Al (Cl-). However, when nitrate and sulfate were used as the precursors, Fe and Al were simultaneously detected in the Fe/Al (NO3-) and Fe/Al (SO42-). These MOFs exhibit ultrafast adsorption kinetics and high uptake capacity for phosphate. The maximum phosphate uptake capacity (130 mg P/g) of Fe/Al (NO3-) is much higher than that of most phosphate removal materials reported in the literature. More importantly, Fe/Al (NO3-) can still effectively remove phosphate from water bodies after multiple cycles of adsorption/desorption. When there are a large number of common interfering ions (Ca2+, Mg2+, CO32-, HCO3-, Cl-, NO3- and SO42-) in the water, the prepared MOFs can still specifically remove phosphorus from water. In addition, the prepared MOFs can adapt to the removal of phosphorus in a wide pH water body. Furthermore, based on FTIR and XPS spectra, chemical adsorption and ligand exchange were identified as the main phosphorus removal mechanisms by Fe/Al (NO3-). These findings prefigure that MOFs synthesized by regulating the anionic species can efficiently and economically remove phosphate from water. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.