a potential bacterial consortium containing anammox-oxidizing bacteria, anammoxdenitrifying bacteria, and anammox bacteria will be efficient for the treatment of
industrial effluents having high concentration of ammonia and organic chemicals.
Further, phytoremediation of TWW is an excellent strategy for its effective
treatment and management. For instance, Kassaye et al. (2017) reported the
phytoremediation potential of swamp smartweed (Polygonum coccineum), para
grass (Brachiaria mutica), and papyrus (Cyprus papyrus) for Cr-containing TWW.
They reported that all the three plants exhibited a significant transfer of Cr from
wastewater to roots and shoots, but removal efficiency of Cr for swamp smartweed
was relatively low as compared to para grass and papyrus and further suggested the
use of para grass and papyrus for effective phytoremediation of TWW. Gupta et al.
(2018) studied the microbe-assisted phytoremediation of tannery effluent contaminated agricultural soils. They isolated a Cr
6+ -resistant plant growth-promoting
Pseudomonas sp. (strain CPSB21) from the tannery effluent-contaminated agricultural soils and evaluated for the various plant growth-promoting activities, oxidative
stress tolerance, and Cr
6+ bioremediation. Further, they applied the isolated strain for
microbe-assisted phytoremediation and reported that the inoculation of strain
CPSB21 alleviated the Cr
6+ toxicity and enhanced the plant growth parameters
and nutrient uptake in sunflower plant during pot experiment. However, the selection
of suitable plants for phytoremediation of TWW is a challenging task as it should
primarily be of high salt and chromium tolerant in nature.
In addition, electrobioremediation is an emerging technology for waste treatment
and management. For instance, Kanagasabi et al. (2012) reported the
electrobioremediation of TWW in electrooxidation reactor containing immobilized
bacterial biomass. They reported a maximum reduction in COD up to 73.1% at
1.5 A dm
À2 from raw TWW using electrooxidation technique and up to 91.5%
reduction in COD from diluted TWW using immobilized Bacillus Strain
B. However, the combined application of electrooxidation and biooxidation
approach was proven good for the degradation of TWW samples and achieved
66.2% and 76.6% COD degradation, respectively. However, the optimization
parameters related to electrical operation such as intensity of electrical field, mode
of current application, the distance between electrodes, and period of stimulation and
their effect on the microbes are the associated key challenges that must be taken into
consideration. From the above discussion, it is clear that every remediation technology has its own merits and demerits and thus wisely chosen. However, further
research efforts are required to expand the scope and efficacy of the remediation
methods used to effectively treat and manage TWW to safeguard the environment
and public health.
3 Conclusions and Recommendations
(a) TWW is ranked as one of the highly toxic wastewaters among all the industrial
wastewater types.
21 Progresses in Bioremediation Technologies for Industrial Waste. . .
535
industrial effluents having high concentration of ammonia and organic chemicals.
Further, phytoremediation of TWW is an excellent strategy for its effective
treatment and management. For instance, Kassaye et al. (2017) reported the
phytoremediation potential of swamp smartweed (Polygonum coccineum), para
grass (Brachiaria mutica), and papyrus (Cyprus papyrus) for Cr-containing TWW.
They reported that all the three plants exhibited a significant transfer of Cr from
wastewater to roots and shoots, but removal efficiency of Cr for swamp smartweed
was relatively low as compared to para grass and papyrus and further suggested the
use of para grass and papyrus for effective phytoremediation of TWW. Gupta et al.
(2018) studied the microbe-assisted phytoremediation of tannery effluent contaminated agricultural soils. They isolated a Cr
6+ -resistant plant growth-promoting
Pseudomonas sp. (strain CPSB21) from the tannery effluent-contaminated agricultural soils and evaluated for the various plant growth-promoting activities, oxidative
stress tolerance, and Cr
6+ bioremediation. Further, they applied the isolated strain for
microbe-assisted phytoremediation and reported that the inoculation of strain
CPSB21 alleviated the Cr
6+ toxicity and enhanced the plant growth parameters
and nutrient uptake in sunflower plant during pot experiment. However, the selection
of suitable plants for phytoremediation of TWW is a challenging task as it should
primarily be of high salt and chromium tolerant in nature.
In addition, electrobioremediation is an emerging technology for waste treatment
and management. For instance, Kanagasabi et al. (2012) reported the
electrobioremediation of TWW in electrooxidation reactor containing immobilized
bacterial biomass. They reported a maximum reduction in COD up to 73.1% at
1.5 A dm
À2 from raw TWW using electrooxidation technique and up to 91.5%
reduction in COD from diluted TWW using immobilized Bacillus Strain
B. However, the combined application of electrooxidation and biooxidation
approach was proven good for the degradation of TWW samples and achieved
66.2% and 76.6% COD degradation, respectively. However, the optimization
parameters related to electrical operation such as intensity of electrical field, mode
of current application, the distance between electrodes, and period of stimulation and
their effect on the microbes are the associated key challenges that must be taken into
consideration. From the above discussion, it is clear that every remediation technology has its own merits and demerits and thus wisely chosen. However, further
research efforts are required to expand the scope and efficacy of the remediation
methods used to effectively treat and manage TWW to safeguard the environment
and public health.
3 Conclusions and Recommendations
(a) TWW is ranked as one of the highly toxic wastewaters among all the industrial
wastewater types.
21 Progresses in Bioremediation Technologies for Industrial Waste. . .
535