Various organic herbicides and pesticides are used to control the growth of
insects and weeds which are harmful plant growth are the main organic contaminants of agriculture wastewater. [86]. The production and use of new and old
medicines and Pharmaceuticals drugs and personal care products including fragrances and antimicrobial agents such as triclosan has been enhanced so it increases
the organic concentration in wastewater [87].
These industrial, domestic, agricultural activities increase the organic contamination of water bodies like oceans, seas, river, lakes, and groundwater. These are
the causes of severe threatening of environment and its degradation. Detecting the
concentration and chemical analysis of these organic contaminants present in
wastewater is an essential step in controlling water pollution and ensuring clean
water supplies. The detection procedure and chemical analysis of these organic
pollutants present in wastewater is a costly process. In this context development of
biosensor makes the detection of organics present in wastewater an easy and efficient process [88]. Kiran et al. found that gas chromatography-mass spectrometry
(GC-MS) and Fourier Transform Infra Red spectroscopy (FTIR) techniques are
useful in detecting the presence of organic compound such as alcohol, aromatic
hydrocarbons such as phenols and amines [89].
Biological oxygen demand BOD and Chemical Oxygen demand COD and Total
organic carbon TOC are important parameters of determining organic contents of
wastewater. BOD is the amount of oxygen required by aerobic microorganisms to
degrade organic matter present in wastewater, expressed in mg/l. BOD method
requires incubation of sample for 5-days at 20 °C. The COD is a measurement of
the oxygen required to oxidize all the organic matter present in a sample [90]. The
measurement of TOC is an alternative method compared to BOD and COD. TOC is
a quick online method and is most preferred then BOD and COD which oxidizes
the entire organic content of the sample. These procedures are time consuming and
difficult and required skill and expertise in handling these samples. Solutions of
these difficulties are achieved by using BOD biosensors, which are fast and produces significant results [91].
Karube et al. discussed a microbial biosensors using immobilization
of Trichosporon cutaneum on the oxygen electrode for BOD determination. These
microbial film immobilize between cellulosic membranes and oxidizes organic
contaminants present in wastewater [92].
Several other microorganisms like Bacillus subtilis, Serratia marcescens and
yeast were used in microbial biosensor for detection of BOD [93–95].
Immobilization of single microorganism has certain limitations as it oxidizes
limited range of organic pollutant present in wastewater so exact determination of
BOD cannot be possible. In order to overcome this limitation an idea of mixed
culture immobilization of Bacillus subtilis and Trichosporon cutaneum were
introduced by Jia et al. in 2003 [96]. Immobilized Bacillus licheniformison clark
oxygen electrode based biosensor is capable of detecting even low concentration
BOD in seawater. This biosensor is very much efficient in measuring BOD in high
salinity condition with fast response [97, 98].
202
R. Sinha et al.
insects and weeds which are harmful plant growth are the main organic contaminants of agriculture wastewater. [86]. The production and use of new and old
medicines and Pharmaceuticals drugs and personal care products including fragrances and antimicrobial agents such as triclosan has been enhanced so it increases
the organic concentration in wastewater [87].
These industrial, domestic, agricultural activities increase the organic contamination of water bodies like oceans, seas, river, lakes, and groundwater. These are
the causes of severe threatening of environment and its degradation. Detecting the
concentration and chemical analysis of these organic contaminants present in
wastewater is an essential step in controlling water pollution and ensuring clean
water supplies. The detection procedure and chemical analysis of these organic
pollutants present in wastewater is a costly process. In this context development of
biosensor makes the detection of organics present in wastewater an easy and efficient process [88]. Kiran et al. found that gas chromatography-mass spectrometry
(GC-MS) and Fourier Transform Infra Red spectroscopy (FTIR) techniques are
useful in detecting the presence of organic compound such as alcohol, aromatic
hydrocarbons such as phenols and amines [89].
Biological oxygen demand BOD and Chemical Oxygen demand COD and Total
organic carbon TOC are important parameters of determining organic contents of
wastewater. BOD is the amount of oxygen required by aerobic microorganisms to
degrade organic matter present in wastewater, expressed in mg/l. BOD method
requires incubation of sample for 5-days at 20 °C. The COD is a measurement of
the oxygen required to oxidize all the organic matter present in a sample [90]. The
measurement of TOC is an alternative method compared to BOD and COD. TOC is
a quick online method and is most preferred then BOD and COD which oxidizes
the entire organic content of the sample. These procedures are time consuming and
difficult and required skill and expertise in handling these samples. Solutions of
these difficulties are achieved by using BOD biosensors, which are fast and produces significant results [91].
Karube et al. discussed a microbial biosensors using immobilization
of Trichosporon cutaneum on the oxygen electrode for BOD determination. These
microbial film immobilize between cellulosic membranes and oxidizes organic
contaminants present in wastewater [92].
Several other microorganisms like Bacillus subtilis, Serratia marcescens and
yeast were used in microbial biosensor for detection of BOD [93–95].
Immobilization of single microorganism has certain limitations as it oxidizes
limited range of organic pollutant present in wastewater so exact determination of
BOD cannot be possible. In order to overcome this limitation an idea of mixed
culture immobilization of Bacillus subtilis and Trichosporon cutaneum were
introduced by Jia et al. in 2003 [96]. Immobilized Bacillus licheniformison clark
oxygen electrode based biosensor is capable of detecting even low concentration
BOD in seawater. This biosensor is very much efficient in measuring BOD in high
salinity condition with fast response [97, 98].
202
R. Sinha et al.