reduced. This leads to an increase in the accumulation of the heavy metals causing
adverse effects. Once the heavy metals enter the food chain, they have extreme toxic
effects. It may also damage nerves, liver and bones along with blocking functional
groups of vital enzymes (Moore 1990; Ewan and Pamphlett 1996).
The soils in which contaminants are associated with soil particles and their
presence can also be seen in soil liquids and in the soil atmosphere,
i.e. multiphasic environments, then an interdisciplinary approach has to be considered (Boopathy 2000).
It is well known that the microorganisms are cosmopolitan due to their amazing
metabolism. Thus, they act as significant solution givers to a wide range of polluted
habitats by carrying out the biodegradation and bioremediation activities, provided
that environmental conditions are suitable for their growth and metabolism (Abatenh
et al. 2017; Azubuike et al. 2016; Verma and Jaiswal 2016). Microorganisms stand
out over other biological tools for the removal of pollutants in various ecosystems,
due to their fast growth and metabolic activities (Demnerovà et al. 2005).
A group of biological mechanisms, which degrades, detoxifies and mineralizes
concentrated pollutants into harmless or significantly less harmful substances, can be
easily utilized by other organisms.
3.3 Criteria for the Selection of Bioremediation Techniques
Pollutants are of various types: agrochemicals, dyes, heavy metals, greenhouse
gases, hydrocarbons, chlorinated compounds, nuclear waste, plastics and sewage.
Depending on the nature of pollutant, ex situ or in situ type of remedial may be
considered (Frutos et al. 2012; Smith et al. 2015).
Before starting off any remediation project, it is extremely essential to check upon
the method or technique based upon the selection and performance criteria. Nutrient
and O 2 concentrations, pH and other abiotic factors are included in the performance
criteria, which will ultimately lead the project towards success. There are a vast
variety of bioremediation techniques available, but most of them are concentrated on
remediation on hydrocarbons pollution, since it is the most common type of pollution (Frutos et al. 2010; Sui and Li 2011; Kim et al. 2014; Firmino et al. 2015;
Abatenh et al. 2017).
Basically, bioremediation is done by the utilization of living organisms. Microorganisms, including both bacteria and fungi, are considered most suitable to
degrade the environmental contaminants into less toxic or toxic-free forms. Even
plants with some basic features too can be very useful for carrying out bioremediation successfully. The selected living organisms may be native to a contaminated
area or they may be introduced to the contaminated area from somewhere else. These
organisms have the ability to transform the contaminant compounds through the
metabolic processes, which enables to convert the pollutants into harmless products.
Bioaugmentation takes place when a set of suitable microbes are brought to the
contaminated site, so as to boost the process of degradation. It is very much essential
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S. K. Yadav
adverse effects. Once the heavy metals enter the food chain, they have extreme toxic
effects. It may also damage nerves, liver and bones along with blocking functional
groups of vital enzymes (Moore 1990; Ewan and Pamphlett 1996).
The soils in which contaminants are associated with soil particles and their
presence can also be seen in soil liquids and in the soil atmosphere,
i.e. multiphasic environments, then an interdisciplinary approach has to be considered (Boopathy 2000).
It is well known that the microorganisms are cosmopolitan due to their amazing
metabolism. Thus, they act as significant solution givers to a wide range of polluted
habitats by carrying out the biodegradation and bioremediation activities, provided
that environmental conditions are suitable for their growth and metabolism (Abatenh
et al. 2017; Azubuike et al. 2016; Verma and Jaiswal 2016). Microorganisms stand
out over other biological tools for the removal of pollutants in various ecosystems,
due to their fast growth and metabolic activities (Demnerovà et al. 2005).
A group of biological mechanisms, which degrades, detoxifies and mineralizes
concentrated pollutants into harmless or significantly less harmful substances, can be
easily utilized by other organisms.
3.3 Criteria for the Selection of Bioremediation Techniques
Pollutants are of various types: agrochemicals, dyes, heavy metals, greenhouse
gases, hydrocarbons, chlorinated compounds, nuclear waste, plastics and sewage.
Depending on the nature of pollutant, ex situ or in situ type of remedial may be
considered (Frutos et al. 2012; Smith et al. 2015).
Before starting off any remediation project, it is extremely essential to check upon
the method or technique based upon the selection and performance criteria. Nutrient
and O 2 concentrations, pH and other abiotic factors are included in the performance
criteria, which will ultimately lead the project towards success. There are a vast
variety of bioremediation techniques available, but most of them are concentrated on
remediation on hydrocarbons pollution, since it is the most common type of pollution (Frutos et al. 2010; Sui and Li 2011; Kim et al. 2014; Firmino et al. 2015;
Abatenh et al. 2017).
Basically, bioremediation is done by the utilization of living organisms. Microorganisms, including both bacteria and fungi, are considered most suitable to
degrade the environmental contaminants into less toxic or toxic-free forms. Even
plants with some basic features too can be very useful for carrying out bioremediation successfully. The selected living organisms may be native to a contaminated
area or they may be introduced to the contaminated area from somewhere else. These
organisms have the ability to transform the contaminant compounds through the
metabolic processes, which enables to convert the pollutants into harmless products.
Bioaugmentation takes place when a set of suitable microbes are brought to the
contaminated site, so as to boost the process of degradation. It is very much essential
88
S. K. Yadav