Publications by authors named "Ioannis Garagounis"

The present research employs a pilot-scale selective electrodialysis system to treat liquid digestate, fractionating nutrient ions and exploring fertilizer creation via ammonia stripping and phosphorus precipitation, while studying pharmaceutical transport behavior and examining membrane fouling. The influence of diverse potentials was studied in simulated and real digestate, with 30 V application proven more efficient overall. Applying consecutive runs resulted in products that were 7.

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In the present work, symmetrical oxide ion conducting solid oxide single cells with inkjet-printed composite LSM-YSZ electrodes, onto commercially available YSZ dense substrates using GDC as buffer interlayer, were fabricated and characterized. Stable inkjet-printable LSM-YSZ nanoparticle inks were developed based on water solvent, after processing with high intensity ball milling. The deposition of LSM-YSZ electrodes was performed by inkjet printing, as well as a conventional additive manufacturing technique, screen printing, in order to compare the electrochemical performance of the produced cells for the reversible charge transfer reaction (O + 4 e ↔ 2 O).

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A combination of membrane processes was applied to treat the digestate produced after the anaerobic treatment of pig manure in a biogas plant, aiming towards the recovery of nutrients and effective water treatment for potential reuse. Initially, coarse filtration (sieving and microfiltration) was used to remove particles larger than 1 µm, followed by ultrafiltration, to reduce the suspended solids concentrations below 1 g/L. Subsequently, selective electrodialysis is employed to recover the main nutrient ions, primarily ammonium and potassium.

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A series of technologies have been employed in pilot-scale to process digestate, i.e. the byproduct remaining after the anaerobic digestion of agricultural and other wastes, with the aim of recovering nutrients and reducing the load of solids and organics from it, hence improving the quality of digestate for potential subsequent reuse.

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Ammonia is a key chemical produced in huge quantities worldwide. Its primary industrial production is via the Haber-Bosch method; a process requiring high temperatures and pressures, and consuming large amounts of energy. In the past two decades, several alternatives to the existing process have been proposed, including the electrochemical synthesis.

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