bezafibrate, primidone, carbamazepine) may not be eliminated through biological
processes (<40%) (Yang et al. 2011). Actual research focuses on the development of
alternative solutions of biological treatments to remove recalcitrant CECs from
municipal and industrial wastewater and some interesting processes include
bioelectrochemical systems (BESs). In such systems, organic CECs can be oxidized
by the bacteria forming a biofilm while electrons are transferred from the microorganisms to the electrode surface. BESs have demonstrated satisfying performances
to remove some CECs (Rodriguez-Narvaez et al. 2017; Werner et al. 2015). Another
promising technology is based on the use of electrochemical membrane bioreactors
with the integration of bioelectrogenesis. Compared to BESs, it reduces the fouling
phenomenon and improves the CECs removals (Ma et al. 2015; Rodriguez-Narvaez
et al. 2017). Biosurfactant applications for remediation of contaminated soil and
water are promising because of their biodegradability, low toxicity, and effectiveness in enhancing biodegradation and affinity for metals/metalloids including
As. Various studies have been performed with regard to the enhanced bioremediation, the flushing and washing of soils, sediments, mining residues, and water
contaminated with metals alone or with hydrocarbons (Mulligan 2017). Removal
of metals by biosurfactants occurs through solubilization, complexation, and ion
exchange.
29.4 Research Needs
Current challenges in the treatment of CECs include some of the following: (1) lack
of analytical methodologies to adequately quantify CECs in complex matrices such
as industrial, municipal, and mine water; (2) uncertainties on operational costs
(necessary infrastructure, chemicals availability); (3) limited creation of residual
salinity (source of toxicity); (4) low volumes of stable sludge, easy and safe to
manage; (5) potential impact of treated effluents on receiving natural water; (6) use
of low toxicity and highly biodegradable, green additives for treatment; 7) reduction
of emissions and energy requirements; and 8) management of the solids produced
during the application of sorption and/or biotechnologies that contain CECs.
Gaps and research needs for the CECs found in municipal and industrial wastewater include: (1) Analytical determination: Improve the knowledge related to the
determination of CECs and their degradation products or metabolites produced after
physicochemical or biological treatments in complex matrices even at very low
concentrations; (2) Toxicity of CECs and their degradation products: Investigate
the toxic effects of many of CECs and their degradation by-products on living
organisms; (3) Distribution and fate of CECs in the environment: Determine the
behavior and fate of CECs and their degradation pathways on the environment to
implement regulations in order to protect surface and groundwater quality; (4) Degradation of CECs: Test the performances of the new physicochemical and/or
biological technologies on real wastewater at pilot plant scale and in the presence
of dissolved organic matter and other coexisting substances to confirm/rebut the
results obtained at laboratory scale.
29 Future Prospects for Treating Contaminants of Emerging Concern in. . .
599
processes (<40%) (Yang et al. 2011). Actual research focuses on the development of
alternative solutions of biological treatments to remove recalcitrant CECs from
municipal and industrial wastewater and some interesting processes include
bioelectrochemical systems (BESs). In such systems, organic CECs can be oxidized
by the bacteria forming a biofilm while electrons are transferred from the microorganisms to the electrode surface. BESs have demonstrated satisfying performances
to remove some CECs (Rodriguez-Narvaez et al. 2017; Werner et al. 2015). Another
promising technology is based on the use of electrochemical membrane bioreactors
with the integration of bioelectrogenesis. Compared to BESs, it reduces the fouling
phenomenon and improves the CECs removals (Ma et al. 2015; Rodriguez-Narvaez
et al. 2017). Biosurfactant applications for remediation of contaminated soil and
water are promising because of their biodegradability, low toxicity, and effectiveness in enhancing biodegradation and affinity for metals/metalloids including
As. Various studies have been performed with regard to the enhanced bioremediation, the flushing and washing of soils, sediments, mining residues, and water
contaminated with metals alone or with hydrocarbons (Mulligan 2017). Removal
of metals by biosurfactants occurs through solubilization, complexation, and ion
exchange.
29.4 Research Needs
Current challenges in the treatment of CECs include some of the following: (1) lack
of analytical methodologies to adequately quantify CECs in complex matrices such
as industrial, municipal, and mine water; (2) uncertainties on operational costs
(necessary infrastructure, chemicals availability); (3) limited creation of residual
salinity (source of toxicity); (4) low volumes of stable sludge, easy and safe to
manage; (5) potential impact of treated effluents on receiving natural water; (6) use
of low toxicity and highly biodegradable, green additives for treatment; 7) reduction
of emissions and energy requirements; and 8) management of the solids produced
during the application of sorption and/or biotechnologies that contain CECs.
Gaps and research needs for the CECs found in municipal and industrial wastewater include: (1) Analytical determination: Improve the knowledge related to the
determination of CECs and their degradation products or metabolites produced after
physicochemical or biological treatments in complex matrices even at very low
concentrations; (2) Toxicity of CECs and their degradation products: Investigate
the toxic effects of many of CECs and their degradation by-products on living
organisms; (3) Distribution and fate of CECs in the environment: Determine the
behavior and fate of CECs and their degradation pathways on the environment to
implement regulations in order to protect surface and groundwater quality; (4) Degradation of CECs: Test the performances of the new physicochemical and/or
biological technologies on real wastewater at pilot plant scale and in the presence
of dissolved organic matter and other coexisting substances to confirm/rebut the
results obtained at laboratory scale.
29 Future Prospects for Treating Contaminants of Emerging Concern in. . .
599