Influence of biological filtration media on the ammonium removal rates from groundwater sources

The paper investigates the influence of the filter media (Leca, Kaldnes) and hydrodynamic configuration (Kaldnes, aeration within the filter media; Kaldnes, pre-aeration of influent and effluent recycle) on the removal performances of ammonium nitrogen (NH4+ -N) from groundwater sources in biological aerated
filters. The results showed that the volumetric removal rates of NH4+ -N were higher for the Leca media (97-261 kg N/m3/day) than for Kaldnes media (30-135 kg N/m3/day), and also for the biofilter with pre-aeration (30-135 kg N/m3/day) than for the aeration within the filter media (13-66 kg N/m3/ day).