PERFORMANCE EVALUATION OF THE ANAEROBIC FLUIDIZED BED
BIOFILM REACTOR: METHANE PRODUCTION FROM GLUCOSE
Shui J. Chen, Graduate Student
Chun T. Li, Professor
Department of Environmental Engineering
National Cheng Kung University
Tainan, Taiwan, Republic of China
Wen K. Shieh, Assistant Professor
Department of Civil Engineering
University of Pennsylvania
Philadelphia, Pennsylvania 19104
INTRODUCTION
The anaerobic fluidized bed biofilm reactor (AFBBR), as illustrated in Figure 1, is a recent process
innovation in anaerobic biotechnology which retains the growth support media (referred to hereafter
as media) in suspension by drag forces exerted by the upflowing wastewater [1,2]. Under fluidized
state, each medium provides a large surface area for biofilm formation and growth. Immobilization
of microorganisms in this fashion in an AFBBR results in a very high reactor biomass holdup which
enables the process to be operated at significantly higher liquid throughputs with practical absence
of biomass wash-out [3,4]. Process intensification (i.e., a reduction in process size while maintaining
a desirable performance) achieved in an AFBBR makes this innovative process particularly attractive
for liquid waste treatment, for biomass conversion, and for biochemical recovery and production [5-
9).
The AFBBR has been investigated for treatment of a wide variety of municipal and industrial
wastewaters as summarized in Table I [10-17]. A full-scale AFBBR is currently under operation in
the U.S. for treatment of soy processing wastewater [18]. This full-scale facility consists of four 20
ft diameter by 41 ft high single-phase fluidized bed reactors with a total design capacity to remove
over 34,000 lb COD per day. The reported gas production rate is 5.4 ft3 CH„/lb COD removed [18].
Because the AFBBR is still at an early stage of development, research efforts are needed to gain
better insight into the complex nature of the process in order to develop a more rational design and
| >-WS
• ••«
• ••«
J,m/b-s
•*•«
;...
• •••
R
• ••
CM
••1
••••
•••
•••
.AFB8R
1
f
^
/ /f~"V-\- Medium
V ^«—' J~ Biofilm
Figure 1. Flow Scheme of an AFBBR. B
= Bioparticle; CM = Cleaned Media; E
= Effluent; F = Feed; G = Gas; M/B-S
= Media Biofilm Separator; R
= Recirculation; WS = Waste Sludge.
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