8 / 20
Page 27
Notes:
allied
academies
Microbiology: Current Research 2017 | Volume 1, Issue 2
Joint Conference
GLOBAL APPLIED MICROBIOLOGY CONFERENCE
MICROBIAL & BIOCHEMICAL RESEARCH AND TECHNOLOGIES
October 18-19, 2017
Toronto, Canada
International Congress on
&
Continuous wastewater treatment contaminated with heavy metals by coupling a microbial fuel cell
and a microbial electrolysis cell
Chansoo Choi, Guorong Xie and Bonsu Lim
Daejeon University, Republic of Korea
T
he main objective of this study was to find the feasibility
of continuous removal of mixed heavy metal ions from
wastewater by coupling a microbial fuel cell (MFC) and a
microbial electrolysis cell (MEC) in a continuous mode (Fig.
1). This research focused on a mixture of chromium (VI) ions,
zinc (II) ions, copper (II) ions, and nickel (II) ions, as a typical
plating solution, to be removed using the MFC-MEC coupled
system. The electrode material was graphite felt. To compare
parameters the system was also run in a batch. In the batch
mode, the effects of Cr (VI) initial concentration on removal
efficiency of Zn (II) and Ni (II) in MEC has been first studied.
The initial concentrations of Cr (VI), Cu (II), Ni (II), and Zn (II)
were all 10 ppm in MFC, and the concentrations of Ni (II)
and Zn (II) were 10 ppm in MEC. As Cr (VI) concentration
increased from 10 ppm to 100 ppm, the voltage supply to
MEC was increased, and Ni (II) and Zn (II) reduction rate
was also increased. EIS has been applied to investigate
the effect of experimental conditions on electrochemical
reactions. The impedance of different Cr (VI) concentrations
from 10 ppm to 100 ppm in MFCs showed that, compared
with low initial Cr (VI) concentrations, higher initial Cr (VI)
concentrations exhibited much lower resistance (Ohmic
resistance; 19.3~13.4 ohms, charge transfer resistance;
28.2~21.5 ohms), and thus the MFCs were able to deliver
more power toward MEC. The initial Cr(VI) concentration
increased power generation by both increasing the cathode
potential and decreasing the resistance of MFC. A typical
current density and power density at the maximum power
point were 1.08 Am-2 and 863 mWm-2 respectively. The
typical removal efficiency for chromium ion by reduction of
Cr (VI) in the MFC was in the range of 96.9%~100% for 10
ppm after 8 hours. That of Cu (II) inMFC was only in the range
of 29.0%~29.7% for 10 ppm. On the other hand, the removal
efficiencies of Ni (II) and Zn (II) in the MEC were in the range
of 55.0%~59.9% and 76.2%~77.6% for 10 ppm, respectively.
The removal efficiencies of Zn (II) and Ni (II) in the MEC were
slowly increased with the initial concentration of Cr (VI) in
the MFC increased. In the continuous mode, effects of the
hydraulic retention time (HRT from 2h to 12h) on the removal
efficiency of 10 ppm solution have been studied. HRT had a
little impact on removal efficiency of each ion. The removal
efficiencies were 55.0%~78.5% for Cr (VI), 30.6%~32.4%
for Cu (II), 55.0%~59.0 for Ni (II), and 75.3%~75.8% for Zn
(II), respectively. Even if the initial concentration of Cr (VI)
significantly changed, the other three ions showed only a
little change as HRT increased because (1) the concentrations
of Ni (II) and Zn (II) in MEC were as low as ppm range, and
(2) remaining un-reacted Cr (VI) and Cu (II) flew into MEC,
interrupting the Ni (II) and Zn (II) reduction in MEC. With one
train the remaining concentrations of Ni (II) and Zn (II) were
4.5 ppm and 2.5 ppm, respectively for HRT of 2h.
Speaker Biography
Chansoo Choi has his expertise and passion in development of microbial fuel cells.
He approaches this method for removal and/or recovery of heavy metals from
wastewaters, simultaneously generating electrical energy. He also has been developing
storage batteries for use to store alternative energy sources, such as solar cells. He
developed gold, copper, and silver recovery models, and mercury, cadmium and lead
removal models after years of experience in research and teaching in universities.
e:
cse110@dju.kr