these days. Chemical pollution of water stands as a major challenge when it comes
to environmental issues. Dyes, petrochemicals, pathogens, organic compounds,
metallic compounds, pharmaceutical waste products etc. are a continuous source of
chemical and biological pollution in water bodies. The situation is quite alarming
with the continuous addition of these pollutants into the water bodies and environment. Emerging contaminants include variety of chemicals used in various
industries as well as daily applications. It ranges from potential sources such as
herbicides, insecticides, pesticides, fertilizers, nanomaterials, petrochemical and
pharmaceutical wastes, dyes, metal ions used in various industrial wastes as well as
biological contaminants. The primary route and highest contaminating source for
the addition of contaminants is industrial wastewater which is directly discharged
into water bodies and then carried forward [1, 2]. A wide variety of synthetic
chemicals used in different industrial practices are emerging as a source of environmental contaminants. These pollutants are classified on the basis of their use,
point of origin and/or effects on the living systems. Some of the potential water
pollution sources include industries, agricultural, domestic sewages, small scale
factories, power plants which releases variety of pollutants such as fertilizers,
pesticides, herbicides, nanoparticles, petrochemicals, plastics, aromatic compounds,
phenolic compounds, metal ions and metal complexes and pharmaceuticals [3]. The
primary route of addition of these contaminants is industrial wastewater carrying
largest concentration of pollutants.
Traditional method of environmental pollutant detection follows discrete sampling methods followed by laboratory analysis. The sampling involves natural
sources which are easily perturbed by various physical, chemical and biological
factors. Discrete sample methods are time consuming, expensive and need high
resolution data for differentiating in aqueous systems. Current time requires robust,
fast response sensors with high sensitivity and bigger lifetime so that the pollution
can be continuously monitored [4]. Present day technological developments need a
fast, reliable, robust and cost effective system for the detection of these pollutants.
New prototypes are to be developed for rapid and on-site detection of these pollutants in terrestrial as well as aquatic ecosystems. Conventional techniques such as
Chromatography as less reliable, demand sample pretreatment and are highly time
taking. High detection limits and less selectivity adds to the drawbacks of conventional detection methods [5–8].
The chapter focuses on such electrochemical sensing devices which have been
proved to be simple and inexpensive when it comes to detection of pollutants at
traces and sometimes even at ultra-traces level. It puts light on their mechanisms
and various modes of applications. Electrochemical techniques are slowly growing
as one the major mode of in situ determination of pollutants in water samples. It is
much reliable and sensitive method for detection and determination of pollutants.
Electrochemical sensor techniques are important subclass of chemical sensing
technology that employs an electrode as transduction element designed in such a
way that it is inexpensive, miniaturized and can be used for on-site detection of
pollutants. These sensing systems are highly sensitive, selective, wide range, small
size and require less power for operating. Electrochemical techniques hold an
162
A. Ojha
to environmental issues. Dyes, petrochemicals, pathogens, organic compounds,
metallic compounds, pharmaceutical waste products etc. are a continuous source of
chemical and biological pollution in water bodies. The situation is quite alarming
with the continuous addition of these pollutants into the water bodies and environment. Emerging contaminants include variety of chemicals used in various
industries as well as daily applications. It ranges from potential sources such as
herbicides, insecticides, pesticides, fertilizers, nanomaterials, petrochemical and
pharmaceutical wastes, dyes, metal ions used in various industrial wastes as well as
biological contaminants. The primary route and highest contaminating source for
the addition of contaminants is industrial wastewater which is directly discharged
into water bodies and then carried forward [1, 2]. A wide variety of synthetic
chemicals used in different industrial practices are emerging as a source of environmental contaminants. These pollutants are classified on the basis of their use,
point of origin and/or effects on the living systems. Some of the potential water
pollution sources include industries, agricultural, domestic sewages, small scale
factories, power plants which releases variety of pollutants such as fertilizers,
pesticides, herbicides, nanoparticles, petrochemicals, plastics, aromatic compounds,
phenolic compounds, metal ions and metal complexes and pharmaceuticals [3]. The
primary route of addition of these contaminants is industrial wastewater carrying
largest concentration of pollutants.
Traditional method of environmental pollutant detection follows discrete sampling methods followed by laboratory analysis. The sampling involves natural
sources which are easily perturbed by various physical, chemical and biological
factors. Discrete sample methods are time consuming, expensive and need high
resolution data for differentiating in aqueous systems. Current time requires robust,
fast response sensors with high sensitivity and bigger lifetime so that the pollution
can be continuously monitored [4]. Present day technological developments need a
fast, reliable, robust and cost effective system for the detection of these pollutants.
New prototypes are to be developed for rapid and on-site detection of these pollutants in terrestrial as well as aquatic ecosystems. Conventional techniques such as
Chromatography as less reliable, demand sample pretreatment and are highly time
taking. High detection limits and less selectivity adds to the drawbacks of conventional detection methods [5–8].
The chapter focuses on such electrochemical sensing devices which have been
proved to be simple and inexpensive when it comes to detection of pollutants at
traces and sometimes even at ultra-traces level. It puts light on their mechanisms
and various modes of applications. Electrochemical techniques are slowly growing
as one the major mode of in situ determination of pollutants in water samples. It is
much reliable and sensitive method for detection and determination of pollutants.
Electrochemical sensor techniques are important subclass of chemical sensing
technology that employs an electrode as transduction element designed in such a
way that it is inexpensive, miniaturized and can be used for on-site detection of
pollutants. These sensing systems are highly sensitive, selective, wide range, small
size and require less power for operating. Electrochemical techniques hold an
162
A. Ojha