conversely, electron acceptors occur in relatively oxidized states and are reduced
during microbial metabolism. The microbial fuel cell (MFC) is the best example of
the biotransformation process, in which organic matter can be converted into energy
using microorganisms (Lovley 2006; Oh et al. 2004; Pant et al. 2010). Many
researchers have focused on the degradation of industrial effluents with energy
production using low-cost electrodes and indigenous microorganisms or mixed
cultures to develop an environmentally sustainable process (Venkata Mohan et al.
2012; Zuo et al. 2006). The CECRI research group (Karthikeyan et al. 2009, 2013;
Rajeswari et al. 2016; Rengasamy and Berchmans 2012) used various industrial
effluents such as soak liquor from the tannery industry with 2–4% sodium chloride
and spoiled wine from the wine industry in MFCs, focusing on degradation and
energy production in an eco-friendly manner. According to the Central Pollution
Control Board (CPCB) of India, 3000–4000 l of soak liquor is generated per ton of
skin. This type of industrial effluent should be treated in an electrochemical method,
the “microbial fuel cell.” Rajeswari et al. (2016) used soak liquor as anolyte in an
MFC for the first time, and Bacillus cereus and Klebsiella oxytoca were used as
microorganisms which were converted into electrical energy when graphite plates
were used as electrode. The chemical oxygen demand (COD) removal efficiency
was about 93 Æ 5%, with a maximum power density of 44.04 mW/m
2 for 168 h of
MFC operation. The selection of suitable electrodes and membranes enhances the
cost of the process. Further, formation of a heterogeneous biofilm on the anode
surface decreased the efficiency whereby direct and indirect electron transfer determines the efficiency of this electrochemical MFC technique. It can be understood
that the biotransformation process is also a slow process wherein the presence of
inorganic content determines the bacterial physiology.
5 Potential Benefits of Converged Electrokinetic
and Biological Processes
The converged EK and biological remediation is a technique that can clean a
contaminated site by the mechanism of both microbiological phenomena for degradation and the EK process for the dispersal of bacteria or transportation of the
microbes, contaminant, nutrients, etc. (Chilingar et al. 1997). An overview of the
electro-bioremediation process and its mechanism for successful application is
discussed next.
5.1 Bacterial Mobility in the Contaminated Soil
In the bioremediation process, the microorganisms must be in contact with bioavailable contaminants. These types of soil environment are favorable for the bacteria
immobilized in situ because microorganisms attached to the soil particles form
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S. Annamalai and M. Sundaram
during microbial metabolism. The microbial fuel cell (MFC) is the best example of
the biotransformation process, in which organic matter can be converted into energy
using microorganisms (Lovley 2006; Oh et al. 2004; Pant et al. 2010). Many
researchers have focused on the degradation of industrial effluents with energy
production using low-cost electrodes and indigenous microorganisms or mixed
cultures to develop an environmentally sustainable process (Venkata Mohan et al.
2012; Zuo et al. 2006). The CECRI research group (Karthikeyan et al. 2009, 2013;
Rajeswari et al. 2016; Rengasamy and Berchmans 2012) used various industrial
effluents such as soak liquor from the tannery industry with 2–4% sodium chloride
and spoiled wine from the wine industry in MFCs, focusing on degradation and
energy production in an eco-friendly manner. According to the Central Pollution
Control Board (CPCB) of India, 3000–4000 l of soak liquor is generated per ton of
skin. This type of industrial effluent should be treated in an electrochemical method,
the “microbial fuel cell.” Rajeswari et al. (2016) used soak liquor as anolyte in an
MFC for the first time, and Bacillus cereus and Klebsiella oxytoca were used as
microorganisms which were converted into electrical energy when graphite plates
were used as electrode. The chemical oxygen demand (COD) removal efficiency
was about 93 Æ 5%, with a maximum power density of 44.04 mW/m
2 for 168 h of
MFC operation. The selection of suitable electrodes and membranes enhances the
cost of the process. Further, formation of a heterogeneous biofilm on the anode
surface decreased the efficiency whereby direct and indirect electron transfer determines the efficiency of this electrochemical MFC technique. It can be understood
that the biotransformation process is also a slow process wherein the presence of
inorganic content determines the bacterial physiology.
5 Potential Benefits of Converged Electrokinetic
and Biological Processes
The converged EK and biological remediation is a technique that can clean a
contaminated site by the mechanism of both microbiological phenomena for degradation and the EK process for the dispersal of bacteria or transportation of the
microbes, contaminant, nutrients, etc. (Chilingar et al. 1997). An overview of the
electro-bioremediation process and its mechanism for successful application is
discussed next.
5.1 Bacterial Mobility in the Contaminated Soil
In the bioremediation process, the microorganisms must be in contact with bioavailable contaminants. These types of soil environment are favorable for the bacteria
immobilized in situ because microorganisms attached to the soil particles form
198
S. Annamalai and M. Sundaram