A microbial fuel cell–membrane bioreactor integrated system for cost-effective
, Xian-Wei Liu
, Wen-Wei Li
, Feng Li
, Yun-Kun Wang
, Guo-Ping Sheng
Raymond J. Zeng
, Han-Qing Yu
School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
Received 9 January 2012
Received in revised form 9 March 2012
Accepted 12 March 2012
Available online 28 April 2012
Microbial fuel cell (MFC)
Membrane bioreactor (MBR)
Microbial fuel cell (MFC) and membrane bioreactor (MBR) are both promising technologies for wastewa-
ter treatment, but both with limitations. In this study, a novel MFC–MBR integrated system, which com-
bines the advantages of the individual systems, was proposed for simultaneous wastewater treatment
and energy recovery. The system favored a better utilization of the oxygen in the aeration tank of MBR
by the MFC biocathode, and enabled a high efﬂuent quality. Continuous and stable electricity generation,
with the average current of 1.9 ± 0.4 mA, was achieved over a long period of about 40 days. The maximum
power density reached 6.0 W m
. Moreover, low-cost materials were used for the reactor construction.
This integrated system shows great promise for practical wastewater treatment application.
Ó 2012 Elsevier Ltd. All rights reserved.
Microbial fuel cells (MFCs) are devices that use bacteria as cat-
alysts to oxidize various substrates and recover electricity [1,2].
MFCs are promising for wastewater treatment processes, but to
achieve practical application there are still many technical and cost
obstacles to overcome . One approach to reduce the barriers and
improve its applicability is to incorporate MFC into existing waste-
water treatment processes [4,5]. In this respect, a continuous-ﬂow
mode of operation is usually adopted, which is regarded as more
suitable for practical wastewater treatment and MFC application
. An integration of MFC with conventional activated sludge pro-
cess was ﬁrst reported by Cha et al. . In this system, an aeration
tank was directly used as the cathode chamber, where the aerobic
bioﬁlm developed on the cathode serve as low-cost and self-sus-
tainable catalyst. To support a continuous-ﬂow operation, the aer-
ation tank was followed by a clariﬁer, and settled sludge was
continuously returned. However, this setup incurs additional cost
for the clariﬁer construction and sludge pumping. Compared with
this design, a MFC–membrane bioreactor (MBR) integrated design
appeared to be more attractive in terms of costs and footprint .
MBRs present a high-efﬁcient technology for wastewater treat-
ment, and recently the development of coarse ﬁlter MBRs have sig-
niﬁcantly lowered the operating cost and promoted its widespread
application [9–14]. A novel bioelectrochemical membrane reactor,
which makes advantage of both a MBR and a MFC process, was re-
cently reported to achieve a maximum power density of
4.35 W m
and good pollutant removal performance attributed
to the high biomass retention and solid rejection . Nevertheless,
that system has a unique and complex reactor design. Speciﬁcally,
a stainless steel mesh was used, which played a dual function of ﬁl-
ter and MFC cathode. Thus, the application of other less-conductive
coarse materials would be limited in that system. In addition, there
might be difﬁculties for the integrated system in keeping an appro-
priate and balanced bioﬁlm, which serve as both the biocatalyst of
MFC and the ﬁltration/fouling layer of MBR. All these make it dif-
ﬁcult to be directly incorporated into the existing MBR facilities
and its practical application might be limited.
Therefore, in this study we develop a more practical MFC–MBR
integrated process, in which the aeration tank of a MBR was di-
rectly used as the cathode chamber. Carbon felt was used as the
cathode to favor bioﬁlm development. In order to further reduce
the investment and operating cost, low-cost nylon mesh were
adopted here as the ﬁlter material. The suitability of such materials
as MBR ﬁlter have been demonstrated in several previous studies
[8,14,15]. This work aims to investigate the feasibility of applying
a relatively simple MFC–MBR integrated system for continuous
wastewater treatment and power generation.
0306-2619/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
Corresponding author. Tel.: +86 551 3607592; fax: +86 551 3601592.
E-mail address: email@example.com (W.-W. Li).
Applied Energy 98 (2012) 230–235
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