risk of pollutant transfer and ecological restoration (Fellet et al. 2011), although
these are difficult without proper soil amendments (Reverchon et al. 2015). The
biochar-mediated bioremediation is a sustainable approach to overcome the effect
of air pollution due to direct burning of crop residue in the fields. Biochar could
work as a soil fertility booster and in toxic pollutant adsorption in soil, so this
practice may be beneficial on commercial and small scale (Fellet et al. 2014;
Beesley et al. 2013).
6 Treatment of Inorganic and Organic Pollutants Through
Biochar in Contaminated Soils
The combined contamination of metals, metalloids, and organic pollutants is
difficult to remediate together because each contamination requires different treatment processes. However, biochar can remediate combined form of pollutants
(organic and inorganic); both contain several types of pollutants (Table 19.2).
(Wang et al. 2010; Chen and Yuan 2011; Tang et al. 2013; Sneath et al. 2013)
through electrostatic interaction and precipitation of heavy metals and the surface
adsorption, partition, and sequestration of organic contaminants (Zhang et al.
2013). One new developed approach (consortium like amendments) of biochar
with iron reported by Sneath et al. (2013) is that neither biochar treatment (1%,
weight/weight) nor iron treatment could successfully reduce leaching of Cu and
As, but single treatment of iron negatively impacted soil structure and plant
mortality. However, the combined treatments of biochar and iron could reduce
the Cu and As leaching and increased phenanthrene degradation and enabled plant
growth, so it is reported that this is a useful practice for the treatment of
co-contaminated mining sites (Sneath et al. 2013). Biochar was more effective
than other composts at reducing Cd and Zn as well as the heavier metals, highly
toxic likely PAHs (Beesley et al. 2010). Biochar could augment the bioremediation
of PAHs in contaminated soil as microbial carriers of immobilized microorganism
technique (Fig. 19.2). Nevertheless, it is important to select an appropriate category of biochar as an immobilized carrier of microorganism for the stimulation of
biodegradation as well as bioremediation (Chen et al. 2012). But the degradation
and remediation potential has been seen higher in two- to four-ring PAHs than fiveto six-ring in contaminated soil treated with biochar (Liu et al. 2015). According to
Zhang et al. (2013), biochar addition to soil could stimulate PAH-metabolizing
bacterial activity by enhancing the number of gene copies related to PAH degradation and changing the community structure of soil microbial community. However, it has been reported that the application of biochar in agricultural purpose can
decrease the efficacy of pesticide, which directly indicates the negative effect on
the industrial production of pesticides (Tang et al. 2013; Evangelou et al. 2015). So
like this, many other controversial facts are accepted in published form; therefore,
further research is needed.
482
C. Singh et al.
these are difficult without proper soil amendments (Reverchon et al. 2015). The
biochar-mediated bioremediation is a sustainable approach to overcome the effect
of air pollution due to direct burning of crop residue in the fields. Biochar could
work as a soil fertility booster and in toxic pollutant adsorption in soil, so this
practice may be beneficial on commercial and small scale (Fellet et al. 2014;
Beesley et al. 2013).
6 Treatment of Inorganic and Organic Pollutants Through
Biochar in Contaminated Soils
The combined contamination of metals, metalloids, and organic pollutants is
difficult to remediate together because each contamination requires different treatment processes. However, biochar can remediate combined form of pollutants
(organic and inorganic); both contain several types of pollutants (Table 19.2).
(Wang et al. 2010; Chen and Yuan 2011; Tang et al. 2013; Sneath et al. 2013)
through electrostatic interaction and precipitation of heavy metals and the surface
adsorption, partition, and sequestration of organic contaminants (Zhang et al.
2013). One new developed approach (consortium like amendments) of biochar
with iron reported by Sneath et al. (2013) is that neither biochar treatment (1%,
weight/weight) nor iron treatment could successfully reduce leaching of Cu and
As, but single treatment of iron negatively impacted soil structure and plant
mortality. However, the combined treatments of biochar and iron could reduce
the Cu and As leaching and increased phenanthrene degradation and enabled plant
growth, so it is reported that this is a useful practice for the treatment of
co-contaminated mining sites (Sneath et al. 2013). Biochar was more effective
than other composts at reducing Cd and Zn as well as the heavier metals, highly
toxic likely PAHs (Beesley et al. 2010). Biochar could augment the bioremediation
of PAHs in contaminated soil as microbial carriers of immobilized microorganism
technique (Fig. 19.2). Nevertheless, it is important to select an appropriate category of biochar as an immobilized carrier of microorganism for the stimulation of
biodegradation as well as bioremediation (Chen et al. 2012). But the degradation
and remediation potential has been seen higher in two- to four-ring PAHs than fiveto six-ring in contaminated soil treated with biochar (Liu et al. 2015). According to
Zhang et al. (2013), biochar addition to soil could stimulate PAH-metabolizing
bacterial activity by enhancing the number of gene copies related to PAH degradation and changing the community structure of soil microbial community. However, it has been reported that the application of biochar in agricultural purpose can
decrease the efficacy of pesticide, which directly indicates the negative effect on
the industrial production of pesticides (Tang et al. 2013; Evangelou et al. 2015). So
like this, many other controversial facts are accepted in published form; therefore,
further research is needed.
482
C. Singh et al.