Bioaugmentation
Bioaugmentation frequently includes the insertion of microorganisms indigenous or
exogenous to the contaminated sites. Two factors that limit the use of added
microbial cultures in a land treatment unit: (1) non-indigenous rarely compete with
an indigenous population to develop and sustain useful population levels and
(2) most soils with long-term exposure to biodegradable waste have indigenous
microorganisms that effectively degrade if the land treatment unit is well managed
(Harekrushna and Kumar 2012).
7.5.5 Phytoremediation
Phytoremediation is defined as the reduction in the concentration of toxic elements
with the help of plants and associated soil microbes in the environments (Greipsson
2011). This technique allows to improve the soil fertility with inputs of organic
matter (Mench et al. 2009).
Techniques
of
phytoremediation
consist
of
phytoextraction
(or phytoaccumulation), phytofiltration, phytostabilization, phytovolatilization, and
phytodegradation (Alkorta et al. 2004).
7.5.5.1 Phytoextraction
Phytoextraction (also known as phytoaccumulation, phytoabsorption, or
phytosequestration) primarily involves the usage of metal-accumulating plants that
absorb the contaminants from soil or water and further translocate and accumulate
the contaminants in aboveground parts, i.e., shoots (Sekara et al. 2005; Yoon et al.
2006; Rafati et al. 2011). Biochemical process involves metal translocation to shoots
which is crucial and desirable for an effective phytoextraction because it is not
feasible to harvest the root part (Zacchini et al. 2009; Tangahu et al. 2011). Plants
suitable for phytoextraction method are Sedum alfredii and Rumex crispus (Rani and
Dhania 2014).
7.5.5.2 Phytofiltration
Phytofiltration is mainly applicable to treat contaminated surface water or wastewater; basically it involves the cleaning up of pollutants from contaminated sites by the
utilization of certain plants (Mukhopadhyay and Maiti 2010). Phytofiltration may be
rhizofiltration (use of plant roots) or blastofiltration (use of seedlings) or
caulofiltration (use of excised plant shoots; Latin caulis ¼ shoot) (MesjaszPrzybylowicz et al. 2004).
7 Natural Biological Treatment of Effluent and Sludges to Combat the Burden of. . .
115
Bioaugmentation frequently includes the insertion of microorganisms indigenous or
exogenous to the contaminated sites. Two factors that limit the use of added
microbial cultures in a land treatment unit: (1) non-indigenous rarely compete with
an indigenous population to develop and sustain useful population levels and
(2) most soils with long-term exposure to biodegradable waste have indigenous
microorganisms that effectively degrade if the land treatment unit is well managed
(Harekrushna and Kumar 2012).
7.5.5 Phytoremediation
Phytoremediation is defined as the reduction in the concentration of toxic elements
with the help of plants and associated soil microbes in the environments (Greipsson
2011). This technique allows to improve the soil fertility with inputs of organic
matter (Mench et al. 2009).
Techniques
of
phytoremediation
consist
of
phytoextraction
(or phytoaccumulation), phytofiltration, phytostabilization, phytovolatilization, and
phytodegradation (Alkorta et al. 2004).
7.5.5.1 Phytoextraction
Phytoextraction (also known as phytoaccumulation, phytoabsorption, or
phytosequestration) primarily involves the usage of metal-accumulating plants that
absorb the contaminants from soil or water and further translocate and accumulate
the contaminants in aboveground parts, i.e., shoots (Sekara et al. 2005; Yoon et al.
2006; Rafati et al. 2011). Biochemical process involves metal translocation to shoots
which is crucial and desirable for an effective phytoextraction because it is not
feasible to harvest the root part (Zacchini et al. 2009; Tangahu et al. 2011). Plants
suitable for phytoextraction method are Sedum alfredii and Rumex crispus (Rani and
Dhania 2014).
7.5.5.2 Phytofiltration
Phytofiltration is mainly applicable to treat contaminated surface water or wastewater; basically it involves the cleaning up of pollutants from contaminated sites by the
utilization of certain plants (Mukhopadhyay and Maiti 2010). Phytofiltration may be
rhizofiltration (use of plant roots) or blastofiltration (use of seedlings) or
caulofiltration (use of excised plant shoots; Latin caulis ¼ shoot) (MesjaszPrzybylowicz et al. 2004).
7 Natural Biological Treatment of Effluent and Sludges to Combat the Burden of. . .
115