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Point-of-use ceramic filters are one of the strategies to address problems associated with waterborne diseases to remove harmful microorganisms in water sources prior to its consumption. In this study, development of adsorption-based ceramic depth filters composed of alumina platelets was achieved using spray granulation (calcined at 800 °C). Their virus retention performance was assessed using cartridges containing granular material (4 g) with two virus surrogates: MS2 and fr bacteriophages. Both materials showed complete removal, with a 7 log10 reduction value (LRV) of MS2 up to 1 L. MgAl2O4-modified Al2O3 granules possessed a higher MS2 retention capacity, contrary to the shortcomings of retention limits in pure Al2O3 granules. No significant decline in the retention of fr occurred during filtration tests up to 2 L. The phase composition and morphology of the materials were preserved during filtration, with no magnesium or aluminum leakage during filtration, as confirmed by X-ray diffractograms, electron micrographs, and inductively coupled plasma-optical emission spectrometry. The proposed MgAl2O4-modified Al2O3 granular ceramic filter materials offer high virus retention, achieving the criterion for virus filtration as required by the World Health Organization (LRV ≥ 4). Owing to their high thermal and chemical stability, the developed materials are thus suitable for thermal and chemical-free regeneration treatments.

A new concept for seasonal energy storage (both heat and power) for low and zero energy buildings based on an aluminium redox cycle (Al→Al3+→Al) is proposed. The main advantage of this seasonal energy storage concept is the high volumetric energy density of aluminium (21 MWh/m3), which exceeds common storage materials like coal. To charge the storage, oxidized aluminium (Al3+) is reduced to elementary aluminium (Al) in a central processing plant using renewable electricity in summer. In winter, during discharging process, the energy stored in aluminium is released in form of hydrogen and heat via the aluminium – water reaction. Hydrogen is directly converted to electricity and heat in a fuel cell. The discharging phase has been investigated using a laboratory-scale experimental setup. In optimized conditions, heat and hydrogen is reliably produced for all types of aluminium forms (grit, pellets, foil). A high efficiency of the conversion to hydrogen was obtained (>95%). The remaining challenge is to optimize the entire cycle, e.g. the aluminium recovery process via the use of climate-neutral inert electrodes.