Effect of Pumice and Sand on the Sustainability of Granular Iron Beds for the Aqueous Removal of Cu II , Ni II , and Zn II

Current knowledge of the basic principles underlying the design of Fe 0 beds is weak. The volumetric expansive nature of iron corrosion was identified as the major factor determining the sustainability of Fe 0 beds. This work attempts to systematically verify developed concepts. Pumice and sand were admixed to 200 g of Fe 0 in column studies (50:50 volumetric proportion). Reference systems containing 100% of each material have been also investigated. The mean grain size of the used materials (in mm) were 0.28 (sand), 0.30 (pumice), and 0.50 (Fe 0 ). The five studied systems were characterized (i) by the time dependent evolution of their hydraulic conductivity (permeability) and (ii) for their efficiency for aqueous removal of Cu II , Ni II , and Zn II (about 0.3 mM of each). Results showed unequivocally that (i) quantitative contaminant removal was coupled to the presence of Fe 0 , (ii) additive admixture lengthened the service life of Fe 0 beds, and (iii) pumice was the best admixing agent for sustaining permeability while the Fe 0 /sand column was the most efficient for contaminant removal. The evolution of the permeability was well‐fitted by the approach that the inflowing solution contained dissolved O 2 . The achieved results are regarded as starting point for a systematic research to optimize/support Fe 0 filter design.