Operation of a three‐phase biofilm fluidized sand bed reactor for aerobic wastewater treatment

Abstract

A biofilm fluidized sand bed column reactor (14 L) has been operated in the three-phase mode on a soluble glucose-yeast hydrolysate substrate in which the biofilm-sand phase (1-2.5 L) was suspended by direct aeration of the bed. Within two weeks a tight biofilm was formed whose activity resulted in a 90% reduction, with loads of 10.7 kg TC/m(3)day. The residence time was 1 h. The biofilm remained intact during operation with high residence times (up to 23 h) over three weeks. Oxygen transfer coefficients varied with aeration rate and sand quantity between 0.02 and 0.04 s(-1) during non growth conditions; they decreased with increasing amounts of clean sand and were higher and relatively independent of the sand fraction with biofilm-covered sand. Aeration rates used in the 14 L reactor were 23-40 L/min (2.4-4.1 cm/s) and were sufficient to suspend 78-92% f the biofilm-covered sand. Clean sand was 50-75% suspended. Oxygen uptake rates varied between 15.4 and 23.1 mol/m(3) h.

Characteristics of three-phase internal loop airlift bioreactors with complete gas recirculation for non-Newtonian fluids

“…This is mainly due to the fact that the increase ofe S makes the coalescence of the gas bubbles easier, resulting in smaller gas-liquid interfacial area, thus causing the decrease in (K L a) R and (K L a) D . Similar results were also obtained by Ryhner et al [31].…”

Impact of ozonation pre-treatment of oil sands process-affected water on the operational performance of a GAC-fluidized bed biofilm reactor

“…Thus, based on the COD removal at the three applied OLRs, the bioreactor was considered to be optimized at an OLR of 1.61 kg COD m -3 d -1 for further operation. After the initial start-up period of 38 days, the bioreactor was operated for 10-12 days at different OLRs and HLRs (phases II-V) which is within the range of phase durations reported previously for FBBRs (Estrada-Arriaga et al 2012;Gonzalez et al 2001;Ryhiner et al 1988). Interestingly, after the initial acclimatization of bacteria the re-acclimatization after adjusting the OLRs is considered to be less than one day (Betancur et al 2009;Buitron et al 2005 In phase I (0-38 days), the bioreactor OLR was 1.61 kg COD m -3 d -1 and a greater than 70 % COD removal rate was obtained in the first 5 days (Fig.…”

Biological decomposition of dichloromethane from a chemical process effluent

“…Such reactors and their characteristic performance in wastewater purification (biofilm development, sludge production, sludge removal, oxygen input systems etc.) were well described and full scale reactors have been erected all over the world (Sutton 1981;Ryhiner et al 1988;Sutton & Mishra 1989). Maximal DM degradation rates of 12 kg DM/m 3-d were reached in the 801 fluidized bed reactor, using a synthetic wastewater containing DM as single carbon and energy source.…”