of 52 micropollutants un-spiked in wastewater treatment plant including carbamazepine, ibuprofen and diclofenac. The study used a two different engineering reactor systems with different glass tube diameters and light-path lengths of solar pilotscale compound parabolic collector. The authors reported that more than 85% of the
micropollutants were degraded after 480 min in the smaller reactor, while over 90%
were degraded at 300 min in reactor with larger dimensions. The design, light-path
length of reactor, inner diameter, and thickness of the glass wall are important factors
to influence an optimum photocatalyst concentration. To achieve satisfactory degradation of pollutants using low TiO 2 concentrations, a wider tube diameter (i.e.,
optical thickness of about 13 mm) could be used to allow optimal absorption of
photons in order to reduce the overall costs of the treatment. Sun et al. (2013)
explored a heterogeneous Fenton-like reaction in aqueous nano-Fe 3 O 4 suspensions
to evaluate the presence of montmorillonite clay for the degradation of carbamazepine and ibuprofen. Finally, Miranda-García et al. (2014) investigated regeneration
approaches for TiO 2 immobilized on glass beads for the degradation of 15 selected
pharmaceuticals and personal care products, including carbamazepine, ibuprofen,
and diclofenac spiked in distilled water at 100 μg/L. In addition, immobilized TiO 2
was the focus of the study conducted by Sarkar et al. (2015). The photocatalyst was
supported in calcium alginate beads and photodegradation experiments performed in
the packed bed photo reactor. Using the same approach, He et al. (2016) evaluated
the application of photocatalysis for ibuprofen, carbamazepine, and diclofenac
removal in real wastewater by combined artificial solar light and immobilized
TiO 2 . The catalyst was coated on sand (200–500 μm) by the sol-gel technique. In
addition, acute and chronic toxicity tests were performed using two algae species
Anabaena flosaquae and Pseudokirchneriella subcapitata and luminescence bacteria (Vibrio fischeri) exposed at different interval times. Before photocatalysis, all
organisms revealed toxicity by growth inhibition, and the green algae was more
sensitive. During photodegradation, chronic toxicity of the pharmaceutical compounds to the algae species decreased significantly. However, for the luminescence
bacteria, the intermediate photoproducts demonstrated similar toxicity to the parent
compound. Immobilized TiO 2 photocatalysis has the main advantages of cost and
step reduction in wastewater treatment. The catalyst separation is not necessary and
displays the possibility of recycling and reusing TiO 2 nanoparticles. However, several catalyst cycles promote TiO 2 fouling (Miranda-García et al. 2014). Approximately four or five cycles of immobilized TiO 2 are enough to maintain
photocatalytic activity (Miranda-García et al. 2014; Sarkar et al. 2015). The use of
hydrogen peroxide/ultraviolet and calcination treatment was demonstrated as adequate strategies to TiO 2 regeneration (Miranda-García et al. 2014).
Powdered activated carbon (powdered activated carbon) can increase the
photocatalytic activity of TiO 2 due to a synergistic effect between powdered activated carbon/TiO 2 interfaces. Rioja et al. (2014) studied the performance of mixed
powdered activated carbon and TiO 2 for carbamazepine, ibuprofen, and diclofenac
degradation. A mechanical mixture (i.e., powdered activated carbon/
TiO 2 + deionized water) and a chemical mixture (i.e., powdered activated carbon/
TiO 2 + acidic alcoholic solution) at 400
C and 500
C calcination temperatures
334
E. M. Saggioro
micropollutants were degraded after 480 min in the smaller reactor, while over 90%
were degraded at 300 min in reactor with larger dimensions. The design, light-path
length of reactor, inner diameter, and thickness of the glass wall are important factors
to influence an optimum photocatalyst concentration. To achieve satisfactory degradation of pollutants using low TiO 2 concentrations, a wider tube diameter (i.e.,
optical thickness of about 13 mm) could be used to allow optimal absorption of
photons in order to reduce the overall costs of the treatment. Sun et al. (2013)
explored a heterogeneous Fenton-like reaction in aqueous nano-Fe 3 O 4 suspensions
to evaluate the presence of montmorillonite clay for the degradation of carbamazepine and ibuprofen. Finally, Miranda-García et al. (2014) investigated regeneration
approaches for TiO 2 immobilized on glass beads for the degradation of 15 selected
pharmaceuticals and personal care products, including carbamazepine, ibuprofen,
and diclofenac spiked in distilled water at 100 μg/L. In addition, immobilized TiO 2
was the focus of the study conducted by Sarkar et al. (2015). The photocatalyst was
supported in calcium alginate beads and photodegradation experiments performed in
the packed bed photo reactor. Using the same approach, He et al. (2016) evaluated
the application of photocatalysis for ibuprofen, carbamazepine, and diclofenac
removal in real wastewater by combined artificial solar light and immobilized
TiO 2 . The catalyst was coated on sand (200–500 μm) by the sol-gel technique. In
addition, acute and chronic toxicity tests were performed using two algae species
Anabaena flosaquae and Pseudokirchneriella subcapitata and luminescence bacteria (Vibrio fischeri) exposed at different interval times. Before photocatalysis, all
organisms revealed toxicity by growth inhibition, and the green algae was more
sensitive. During photodegradation, chronic toxicity of the pharmaceutical compounds to the algae species decreased significantly. However, for the luminescence
bacteria, the intermediate photoproducts demonstrated similar toxicity to the parent
compound. Immobilized TiO 2 photocatalysis has the main advantages of cost and
step reduction in wastewater treatment. The catalyst separation is not necessary and
displays the possibility of recycling and reusing TiO 2 nanoparticles. However, several catalyst cycles promote TiO 2 fouling (Miranda-García et al. 2014). Approximately four or five cycles of immobilized TiO 2 are enough to maintain
photocatalytic activity (Miranda-García et al. 2014; Sarkar et al. 2015). The use of
hydrogen peroxide/ultraviolet and calcination treatment was demonstrated as adequate strategies to TiO 2 regeneration (Miranda-García et al. 2014).
Powdered activated carbon (powdered activated carbon) can increase the
photocatalytic activity of TiO 2 due to a synergistic effect between powdered activated carbon/TiO 2 interfaces. Rioja et al. (2014) studied the performance of mixed
powdered activated carbon and TiO 2 for carbamazepine, ibuprofen, and diclofenac
degradation. A mechanical mixture (i.e., powdered activated carbon/
TiO 2 + deionized water) and a chemical mixture (i.e., powdered activated carbon/
TiO 2 + acidic alcoholic solution) at 400
C and 500
C calcination temperatures
334
E. M. Saggioro