title: Improvement of the properties of granular sludge in UASB reactors by flow pulsation.
abstract: The objective of this work is to improve the characteristics of granular sludge by modification of the hydraulics of the bed through flow pulsation. Three UASB reactors, two operated with pulsing flow (P1 and P2) and a third without pulsation (NP), were started-up. Both recycling and feeding flow were pulsed in the reactor P1, while in reactor P2, only the feeding was pulsed. A high increase in the removal capacity and stability were achieved by applying pulsation in reactors P1 and P2 when compared to the non-pulsed one. Besides, pulsation promotes the formation of particles of smaller size and higher porosity, thus increasing the specific surface of the bed and consequently, the specific activity. In fact, while reactors P1 and P2 had a 95% COD removal when working at high organic loading rates (12 kg COD/m3 x d), reactor NP only reached 6 kg COD/m3 x d with 85% of removal capacity.
authors.affiliation: Dept. of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Franco
authors.forename: E
authors.initials: E
authors.lastname: Roca
authors.forename: J M
authors.initials: JM
authors.lastname: Lema
mesh_terms: D018533:Biomass; D019149:Bioreactors; D005160:Facility Design and Construction; D010316:Particle Size; D016062:Porosity; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements
chemical_list: D012722:Sewage