technology. Bioremediation involves (Maszenan et al. 2011) bioattenuation (natural
process of degradation and can be monitored by a decrease in pollutant concentration
with increasing time), biostimulation (intentional stimulation of pollutant degradation
by addition of water, nutrients, and electron donors or acceptors), and bioaugmentation
(addition of laboratory-grown microbes with potential for degradation). A great deal of
literature can be found in the public domain on the biodegradation and bioremediation
of industrial waste/pollutants using individual microbe and microbial consortia (see,
Pandey et al. 2007; Maszenan et al. 2011; Singh et al. 2011; Megharaj et al. 2011;
Paisio et al. 2012; Saxena and Bharagava 2017; Saxena et al. 2015; Bharagava et al.
2018).
For instance, Kim et al. (2014) reported 98.3% of COD and 88.5% of Cr removal
from tannery wastewater (TWW). Noorjahan (2014) reported 90% of COD, 90% of
BOD, and 63.8% of Cr removal from TWW using E. coli and 95.4% of COD and
BOD and 73.5% of Cr removal from TWW using Bacillus sp. Yusuf et al. (2013)
reported 87.6% of COD from TWW using B. subtilis and 85.2% of COD from TWW
using P. fragi. El-Bestawy et al. (2013) reported 79.16 of COD, 94.14 of BOD, and
93.66 of Cr from TWW using an optimized bacterial consortium containing
Providencia vermicola W9B-11, Escherichia coli O7:K1 CE10, Bacillus
sp. 58, Bacillus amyloliquefaciens T004, Pseudomonas stutzeri M15-10-3, and
Bacillus sp. PL47. Sivaprakasam et al. (2008) also reported 80% of COD removal
from TWW using a bacterial consortium (P. aeruginosa, B. flexus, E. homiense, and
S. aureus).
2.2 Phytoremediation
Phytoremediation is a low-cost and eco-sustainable in situ remediation technology.
It is advantageous over the conventional physicochemical cleanup methods that
require high capital investment and labor, alter soil properties, and disturb soil
microflora. Phytoremediation is a type of bioremediation wherein green plants
with associated microbes are used for the removal of toxic metals from the contaminated matrix to safeguard the environment and public health. It involves different
strategies such as phytoextraction, phytostabilization, phytodegradation,
phytostimulation, phytovolatilization, and rhizofiltration to remove metal pollutants
from the contaminated sites (Lee 2013; Chandra et al. 2015; Chirakkara et al. 2016).
It can be commercialized, and income can be generated, if metals removed from
contaminated sites could be utilized as “bio-ore” to extract usable form of economically viable metals (i.e., phytomining) (Chandra et al. 2015; Mahar et al. 2016).
Bioenergy can be generated through the burning of plant biomass, and land restoration can be achieved for sustainable agricultural development or general habitation
(Lintern et al. 2013; Stephenson and Black 2014; Mahar et al. 2016). The rationale,
mechanisms, and economic feasibility of phytoremediation have been discussed
elsewhere (Ali et al. 2013; Wan et al. 2016; Sarwar et al. 2017). A great deal of
literature can be found in the public domain on the phytoremediation of heavy metals
5 Emerging and Ecofriendly Technologies for the Removal of Organic and. . .
115
process of degradation and can be monitored by a decrease in pollutant concentration
with increasing time), biostimulation (intentional stimulation of pollutant degradation
by addition of water, nutrients, and electron donors or acceptors), and bioaugmentation
(addition of laboratory-grown microbes with potential for degradation). A great deal of
literature can be found in the public domain on the biodegradation and bioremediation
of industrial waste/pollutants using individual microbe and microbial consortia (see,
Pandey et al. 2007; Maszenan et al. 2011; Singh et al. 2011; Megharaj et al. 2011;
Paisio et al. 2012; Saxena and Bharagava 2017; Saxena et al. 2015; Bharagava et al.
2018).
For instance, Kim et al. (2014) reported 98.3% of COD and 88.5% of Cr removal
from tannery wastewater (TWW). Noorjahan (2014) reported 90% of COD, 90% of
BOD, and 63.8% of Cr removal from TWW using E. coli and 95.4% of COD and
BOD and 73.5% of Cr removal from TWW using Bacillus sp. Yusuf et al. (2013)
reported 87.6% of COD from TWW using B. subtilis and 85.2% of COD from TWW
using P. fragi. El-Bestawy et al. (2013) reported 79.16 of COD, 94.14 of BOD, and
93.66 of Cr from TWW using an optimized bacterial consortium containing
Providencia vermicola W9B-11, Escherichia coli O7:K1 CE10, Bacillus
sp. 58, Bacillus amyloliquefaciens T004, Pseudomonas stutzeri M15-10-3, and
Bacillus sp. PL47. Sivaprakasam et al. (2008) also reported 80% of COD removal
from TWW using a bacterial consortium (P. aeruginosa, B. flexus, E. homiense, and
S. aureus).
2.2 Phytoremediation
Phytoremediation is a low-cost and eco-sustainable in situ remediation technology.
It is advantageous over the conventional physicochemical cleanup methods that
require high capital investment and labor, alter soil properties, and disturb soil
microflora. Phytoremediation is a type of bioremediation wherein green plants
with associated microbes are used for the removal of toxic metals from the contaminated matrix to safeguard the environment and public health. It involves different
strategies such as phytoextraction, phytostabilization, phytodegradation,
phytostimulation, phytovolatilization, and rhizofiltration to remove metal pollutants
from the contaminated sites (Lee 2013; Chandra et al. 2015; Chirakkara et al. 2016).
It can be commercialized, and income can be generated, if metals removed from
contaminated sites could be utilized as “bio-ore” to extract usable form of economically viable metals (i.e., phytomining) (Chandra et al. 2015; Mahar et al. 2016).
Bioenergy can be generated through the burning of plant biomass, and land restoration can be achieved for sustainable agricultural development or general habitation
(Lintern et al. 2013; Stephenson and Black 2014; Mahar et al. 2016). The rationale,
mechanisms, and economic feasibility of phytoremediation have been discussed
elsewhere (Ali et al. 2013; Wan et al. 2016; Sarwar et al. 2017). A great deal of
literature can be found in the public domain on the phytoremediation of heavy metals
5 Emerging and Ecofriendly Technologies for the Removal of Organic and. . .
115