Influence of upflow velocity on performance and biofilm characteristics of Anaerobic Fluidized Bed Reactor (AFBR) in treating high-strength wastewater

One of the key parameters in fluidized bed reactors is the control of biofilm thickness and configuration. the effectof upflow velocity on performance and biofilm characteristics of an anaerobic fluidized bed reactor was studied intreating currant wastewater at various loading rates. the reactor used this study was made of a plexiglass columnbeing 60 mm diameter, 140 cm height, and a volume of 3.95 l. the results demonstrated that the afbr system iscapable of handling an exceptionally high organic loading rate. at organic loading rates of 9.4 to 24.2 (kg cod m?3)at steady state, reactor performances with upflow velocities of 0.5, 0.75 and 1 (m min?1) were 89.3- 63.4, 96.9 – 79.6and 95 – 73.4 percent, respectively. the average biomass concentration per unit volume of the afbr (as gvssatt l?1expended bed) decreased with the increase of upflow velocity in the range of 0.5–1 m min?1 at all applied organicloading rates. the total biomass in the reactor increased with increases in the organic loading rate. the peak biomassconcentration per unit volume (as gvssatt l?1 expended bed) was observed at the bottom part of the reactor, then itdroped off slowly towards the top. the biofilm thickness increased from the bottom to the top of the reactorrepresenting a stratification of the media in the afbr. the bed porosity increased from the bottom to the top ofthe reactor.