Fumarate based Metal Organic Frameworks for water remediation and other applications

This thesis reports the aqueous synthesis and characterization of three fumarate-based MOFs Aluminum fumarate, Zirconium fumarate and Gallium fumarate (hereafter abbreviated as Al(fum), Zr(fum), Ga(fum)), that are porous frameworks of metal nodes bridged by fumarate. Phase formation was confirmed by ATR-FTIR, PXRD, SEM, TGA, and ICP-OES. The core work, carried out in collaboration with the groups of Prof.s Dario Frascari and Davide Pinelli at the Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), investigated the use of Al(fum) and Zr(fum) as adsorbents for phosphate removal from real sludge-line effluents (SWW), tested neat and diluted with wastewater treatment plant effluent (WWTP). The MOFs were first tested as powders to assess adsorption capacity, then granulated to evaluate industrial potential in fixed-bed columns. The program targeted three goals: assessing mechanical robustness under hydraulic load, verifying that granulation does not impair performance (e.g., by reducing accessible surface area and active sites), and evaluating regenerability after the first adsorption cycle. A comparison was carried out between the performance of the MOFs and that of Sorbacid 911 and pyroaurite, two porous adsorbents previously tested by the DICAM group. The former is extremely high-performing but presents challenges for industrial application, whereas the latter is less performant yet more amenable to scale-up. In our tests, both MOFs outperformed pyroaurite but remained below Sorbacid 911, whose deployment is hindered by capacity loss upon granulation and costly regeneration. Accordingly, two priorities emerge: a more efficient desorption strategy for Zr(fum) to reduce bed-volume demand, and improved mechanical stability of Al(fum) in columns, since the granulate did not retain the target particle size in water. In parallel, with TFL Italia S.p.A., we explored an Al(fum) emulsion as a leather-finishing additive to mitigate VOC-related odors.