title: Evaluation of hydraulic characteristics of a pilot-scale air-lift internal-loop bioreactor.
abstract: Using sodium fluoride as tracer, residence time distribution technique was employed to evaluate the hydraulic characteristics of a pilot-scale Internal-Loop Airlift Bio-particle (ILAB) bioreactor that was a novel system for ammonia removal from wastewater. The results showed that the flow pattern of ILAB reactor was close to completely mixed reactor under all the tested air flow rates and liquid flow rates (with average N of 1.88). The total dead zone (TDZ) was 32.43% with biological dead zone (BDZ) of 20.66% and hydraulic dead zone (HDZ) of 8.95%. At higher air flow rates, the flow pattern of reactor approached that of completely mixed reactor (N from 2.72 to 1.54), and the increase of air flow rate gave rise to the decrease of TDZ in the reactor (from 36.24% to 23.00%). Whereas at higher liquid flow rates, the flow pattern of ILAB reactor got away from that of completely mixed reactor (N from 1.51 to 1.72), and the increase of liquid flow rate yielded a rise of TDZ in the reactor (from 28.48% to 36.84%). The study highlighted that the effect of air flow rate on flow pattern and TDZ of the reactor was greater than that of liquid flow rate.
authors.affiliation: a Department of Environmental Engineering , Zhejiang University , Hangzhou , China.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Abbas
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.forename: Hongtao
authors.initials: H
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Zheng
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.forename: Bibi Saima
authors.initials: BS
authors.lastname: Zeb
authors.forename: Jiqiang
authors.initials: J
authors.lastname: Zhang
mesh_terms: D019149:Bioreactors; D004867:Equipment Design; D057446:Hydrodynamics; D010865:Pilot Projects; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D062065:Wastewater
keywords: Air flow effect; dead zone; flow pattern; hydrodynamics; liquid flow effect; residence time distribution; tracer test