and in Asia, it is third (World Economic Forum). In response to this, several in situ
and ex situ technologies were proposed by different groups of researchers for
taking up large-scale clean-up of contaminated sites. However, certain limiting
factors such as high operational and maintenance cost, high energy requirements,
destructive methodologies, time constraints, etc. restrict their widespread application (Zelmanov and Semiat 2008).
In the past few decades, nanotechnology application has occupied various
sectors of our life such as medicine, textiles, pharmaceutics, electronics, optics,
cosmetics, sports, and many more. The area of environmental remediation also has
not been left untouched by nanotechnology. It is evident from the research ongoing
and number of articles published in this field that nanotechnology could take up
remediation tasks and challenges efficiently (Tratnyek and Johnson 2006; Mueller
and Nowack 2010; Singh and Misra 2014; 2016; Patil et al. 2016). Recently, the
concept of sustainable remediation has acquired a great importance, as it essentially aims at reducing the contaminant concentrations to risk-based levels and
alleviating the additional environmental impacts. Recent development made in this
arena has incorporated multiple technologies together in single system so that a
complete solution could be provided that can decontaminate the site economically
in a time efficient manner as well as improve the quality of the site through
restoration. Among restoration methods, bioremediation is one which could combat contamination issues in an economic and environment-friendly way. Bioremediation essentially uses the microorganisms to remediate the pollutants present in
water and soil matrices (Saxena et al. 2019; Bharagava et al. 2017a, b; Gautam
et al. 2017; Saxena et al. 2016; Chandra et al. 2015; Saxena and Bharagava 2017;
Saxena and Bharagava 2015; Perelo 2010; Mosa et al. 2016). According to the
EPA, bioremediation is a “treatment that uses naturally occurring organisms to
break down hazardous substances into less toxic or non toxic substances.” It has
several advantages over physicochemical methods such as high selectivity, specificity, cost and energy efficiency, minimal requirement, etc. However, bioremediation has its limitation too, that is, it takes a long period of time for carrying out
degradation of a toxic compound, typically several months to over a year. Moreover, its application becomes restricted in cases of sites severely contaminated with
highly toxic and hazardous pollutants (Azubuike et al. 2016).
As every method has its own benefits and setbacks, the integration of remediation
methods could be thought of as a solution to tackle remediation problems. Nanobioremediation is one of such kind of methods which received a lot of attention in the
past few years. Nano-bioremediation exploits the benefits of nanotechnology
together with advantages of bioremediation. The present chapter provides a brief
account of nanotechnology and variety of nanostructured materials reported for
removing organic and inorganic contaminants from environmental matrices
followed by detailed description of nano-bioremediation technique, its application
processes, and methods.
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R. Singh et al.
and ex situ technologies were proposed by different groups of researchers for
taking up large-scale clean-up of contaminated sites. However, certain limiting
factors such as high operational and maintenance cost, high energy requirements,
destructive methodologies, time constraints, etc. restrict their widespread application (Zelmanov and Semiat 2008).
In the past few decades, nanotechnology application has occupied various
sectors of our life such as medicine, textiles, pharmaceutics, electronics, optics,
cosmetics, sports, and many more. The area of environmental remediation also has
not been left untouched by nanotechnology. It is evident from the research ongoing
and number of articles published in this field that nanotechnology could take up
remediation tasks and challenges efficiently (Tratnyek and Johnson 2006; Mueller
and Nowack 2010; Singh and Misra 2014; 2016; Patil et al. 2016). Recently, the
concept of sustainable remediation has acquired a great importance, as it essentially aims at reducing the contaminant concentrations to risk-based levels and
alleviating the additional environmental impacts. Recent development made in this
arena has incorporated multiple technologies together in single system so that a
complete solution could be provided that can decontaminate the site economically
in a time efficient manner as well as improve the quality of the site through
restoration. Among restoration methods, bioremediation is one which could combat contamination issues in an economic and environment-friendly way. Bioremediation essentially uses the microorganisms to remediate the pollutants present in
water and soil matrices (Saxena et al. 2019; Bharagava et al. 2017a, b; Gautam
et al. 2017; Saxena et al. 2016; Chandra et al. 2015; Saxena and Bharagava 2017;
Saxena and Bharagava 2015; Perelo 2010; Mosa et al. 2016). According to the
EPA, bioremediation is a “treatment that uses naturally occurring organisms to
break down hazardous substances into less toxic or non toxic substances.” It has
several advantages over physicochemical methods such as high selectivity, specificity, cost and energy efficiency, minimal requirement, etc. However, bioremediation has its limitation too, that is, it takes a long period of time for carrying out
degradation of a toxic compound, typically several months to over a year. Moreover, its application becomes restricted in cases of sites severely contaminated with
highly toxic and hazardous pollutants (Azubuike et al. 2016).
As every method has its own benefits and setbacks, the integration of remediation
methods could be thought of as a solution to tackle remediation problems. Nanobioremediation is one of such kind of methods which received a lot of attention in the
past few years. Nano-bioremediation exploits the benefits of nanotechnology
together with advantages of bioremediation. The present chapter provides a brief
account of nanotechnology and variety of nanostructured materials reported for
removing organic and inorganic contaminants from environmental matrices
followed by detailed description of nano-bioremediation technique, its application
processes, and methods.
166
R. Singh et al.