title: Wastewater treatment by periodic biofilter characterized by aerobic granular biomass.
abstract: The paper reports the results of an experimental investigation aimed at evaluating the role of hydrodynamic conditions on generation and main properties of granular biomass grown under aerobic conditions in a periodic packed bed reactor. During the start-up period, the trend of the hydrodynamic shear forces, calculated by a methodology previous developed by authors, provided a key for explaining the process of biomass granulation. The granular biomass was characterized by a high density (i.e., 70-120 gVSS/Lbiomass) that permitted to achieve a biomass concentration such high as 20-38 gVSS/Lbed. The biomass density increased with the increase of shear forces. The EPS (Extracellular Polymeric Substances) content of the biomass (5-7% of the total organic matter) was not affected by hydrodynamic shear forces as well as the biomass protein content. Periodic packed bed reactor applied to a municipal wastewater showed performances very satisfactory with high efficiencies removal (around 90%) for both COD and ammonia, up to an applied organic loading value of 5.7 kgCOD/m3.d, and negligible sludge production.
authors.affiliation: Istituto di Ricerca Sulle Acque, CNR, Roma, RM, Italy. ramadori@irsa.cnr.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Ramadori
authors.forename: Claudio
authors.initials: C
authors.lastname: Di Iaconi
authors.forename: Antonio
authors.initials: A
authors.lastname: Lopez
authors.forename: Roberto
authors.initials: R
authors.lastname: Passino
mesh_terms: D000332:Aerobiosis; D001420:Bacteria, Aerobic / Q000254:growth & development* / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D005374:Filtration / Q000295:instrumentation; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D011135:Polysaccharides, Bacterial