biphenyls produced after the dechlorination of PCB by bacterial metabolism. In this
study, no toxic effect toward microorganisms by the nZVI was observed.
Further, Bokare et al. (2012) conducted a study into the feasibility of an integration of bioremediation process and reductive process through nanoparticles in a
contaminated solution with triclosan (5 g/L). The researchers promoted a sequential
degradation of the contaminant by subjecting it to an anaerobic dechlorination
through the nanoparticles of Pd/Fe. Subsequently, further remediation is achieved
by oxidation of the by-products through the application of the enzyme produced by
Trametes versicolor (laccase producing fungi). The results showed complete dechlorination of triclosan in 20 min after application and its by-products totally oxidized
by microbial enzyme. Thus, nano-bioremediation could be an excellent strategy for
the remediation of contaminants in environmental matrix.
3 Challenges and Future Prospects
Bioremediation has emerged as a low-cost alternative to conventional remediation
technologies, which are environmentally destructive and costly and create secondary
pollution and, thus, negatively affect the ecosystem. However, it may get restricted
by several factors such as low or non-bioavailability of pollutants to microbes,
toxicity of pollutants to microbes and remediating plants, lack of enzymes responsible for the degradation and detoxification of specific environmental pollutants,
recalcitrant nature of environmental pollutants, and low biomass, toxicity of
nanoparticles to microbes as in the case of nano-bioremediation and slow growth
rate of remediating plants as in the case of phytoremediation. Further, molecular
techniques may advance the meaning of bio- and phytoremediation by developing
transgenic microbes and plants for environmental remediation, but environmental
risks such as invasion of exotic plants and loss of biodiversity associated with
transgenic organisms make them less feasible for environmental decontamination.
Moreover, the strict US and Western countries’ regulations on the use of these
organisms also restrict their filed applications. These limitations are sufficient to
discredit the applicability of bioremediation technologies and together constitute a
major challenge in the way of success at field scale. Moreover, several emerging and
ecofriendly approaches can be suitable alternative for the conventional bioremediation technologies. Electrobioremediation, electrokinetic phytoremediation, nanobioremediation, constructed wetlands, and microbial fuel cell technology represent a
highly promising and sustainable future in waste treatment and management. However, these have some serious challenges that need to be catch-up for wide applications in a more sustainable and economic manner. Further, future research efforts
may provide new ways to make the bioremediation technologies more efficient for
environmental remediation.
5 Emerging and Ecofriendly Technologies for the Removal of Organic and. . .
121
study, no toxic effect toward microorganisms by the nZVI was observed.
Further, Bokare et al. (2012) conducted a study into the feasibility of an integration of bioremediation process and reductive process through nanoparticles in a
contaminated solution with triclosan (5 g/L). The researchers promoted a sequential
degradation of the contaminant by subjecting it to an anaerobic dechlorination
through the nanoparticles of Pd/Fe. Subsequently, further remediation is achieved
by oxidation of the by-products through the application of the enzyme produced by
Trametes versicolor (laccase producing fungi). The results showed complete dechlorination of triclosan in 20 min after application and its by-products totally oxidized
by microbial enzyme. Thus, nano-bioremediation could be an excellent strategy for
the remediation of contaminants in environmental matrix.
3 Challenges and Future Prospects
Bioremediation has emerged as a low-cost alternative to conventional remediation
technologies, which are environmentally destructive and costly and create secondary
pollution and, thus, negatively affect the ecosystem. However, it may get restricted
by several factors such as low or non-bioavailability of pollutants to microbes,
toxicity of pollutants to microbes and remediating plants, lack of enzymes responsible for the degradation and detoxification of specific environmental pollutants,
recalcitrant nature of environmental pollutants, and low biomass, toxicity of
nanoparticles to microbes as in the case of nano-bioremediation and slow growth
rate of remediating plants as in the case of phytoremediation. Further, molecular
techniques may advance the meaning of bio- and phytoremediation by developing
transgenic microbes and plants for environmental remediation, but environmental
risks such as invasion of exotic plants and loss of biodiversity associated with
transgenic organisms make them less feasible for environmental decontamination.
Moreover, the strict US and Western countries’ regulations on the use of these
organisms also restrict their filed applications. These limitations are sufficient to
discredit the applicability of bioremediation technologies and together constitute a
major challenge in the way of success at field scale. Moreover, several emerging and
ecofriendly approaches can be suitable alternative for the conventional bioremediation technologies. Electrobioremediation, electrokinetic phytoremediation, nanobioremediation, constructed wetlands, and microbial fuel cell technology represent a
highly promising and sustainable future in waste treatment and management. However, these have some serious challenges that need to be catch-up for wide applications in a more sustainable and economic manner. Further, future research efforts
may provide new ways to make the bioremediation technologies more efficient for
environmental remediation.
5 Emerging and Ecofriendly Technologies for the Removal of Organic and. . .
121