both organic contaminants and water which leads to the formation of hydroxyl
radicals (HO•) (Hanel et al. 2010; Munter et al. 2001).
A wide range of oxide semiconductors such as TiO 2 , ZnO, ZrO 2 , WO 3 , and
Fe 2 O 3 ; non-oxide semiconductors such as ZnS, MoS 2 , and CdS; or doped semiconductors such as ZnS–CuS–CdS, ZnS–WS 2 –CdS, C 3 N 4 –CdS, g-C 3 N 4 –Au–CdS,
Pd–Cr 2 O 3 –CdS, and carbon spheres/CdS have been tested for removing of a large
spectrum of refractory organic compounds from wastewater. Of all these semiconductors or photocatalysts, titanium dioxide (TiO 2 ) in the anatase form remains the
most popular one used in photocatalytic processes due to the advantages it offers
such as high oxidizing ability, photodurability, nontoxicity, mechanical robustness,
and low cost (Byrne et al. 2018; Wei et al. 2016; Mansourpanah et al. 2009).
TiO 2 or other photocatalysts can be used either in suspension or deposited on a
membrane (Mozia 2010; Li et al. 2009; Lim et al. 2009). The photocatalytic
membrane reactors are preferred because, on the one hand, they solve the problems
regarding the separation of the photocatalyst from the system and, on the other hand,
have the advantage of continuous operation (Mozia 2010). A wide range of organic,
inorganic, and metallic materials were used to prepare photocatalytic membranes. In
this respect, the most popular organic materials used to prepare photocatalytic
membranes are polyamide, polyethersulfone, polyvinylidene fluoride, polyurethane,
polyethylene terephthalate, polyacrylonitrile, and polytetrafluoroethylene (Argurio
et al. 2018). The most common materials used to prepare ceramic photocatalytic
membranes are aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ), zirconium dioxide (ZrO 2 ), silicon dioxide (SiO 2 ), and some mixes between them (Teik-Thye and
Ron 2016).
Advanced oxidation processes have a number of advantages in the wastewater
treatment, namely:
• High degradation rates of organic compounds from aqueous phase, without
transferring pollutants into another phase.
• High reactivity of OH• radicals that react with almost all pollutants from water.
• During oxidation processes, heavy metals could precipitate as hydroxides and can
be removed in a subsequent stage.
• OH• radicals facilitate the disinfection during the wastewater/water treatment
simultaneously with the organic compounds’ degradation.
• Theoretically, no other new organic compounds with higher toxicity are
produced.
13 Photocatalytic Degradation of Chlorophenols and Antibiotics from Wastewater
417
radicals (HO•) (Hanel et al. 2010; Munter et al. 2001).
A wide range of oxide semiconductors such as TiO 2 , ZnO, ZrO 2 , WO 3 , and
Fe 2 O 3 ; non-oxide semiconductors such as ZnS, MoS 2 , and CdS; or doped semiconductors such as ZnS–CuS–CdS, ZnS–WS 2 –CdS, C 3 N 4 –CdS, g-C 3 N 4 –Au–CdS,
Pd–Cr 2 O 3 –CdS, and carbon spheres/CdS have been tested for removing of a large
spectrum of refractory organic compounds from wastewater. Of all these semiconductors or photocatalysts, titanium dioxide (TiO 2 ) in the anatase form remains the
most popular one used in photocatalytic processes due to the advantages it offers
such as high oxidizing ability, photodurability, nontoxicity, mechanical robustness,
and low cost (Byrne et al. 2018; Wei et al. 2016; Mansourpanah et al. 2009).
TiO 2 or other photocatalysts can be used either in suspension or deposited on a
membrane (Mozia 2010; Li et al. 2009; Lim et al. 2009). The photocatalytic
membrane reactors are preferred because, on the one hand, they solve the problems
regarding the separation of the photocatalyst from the system and, on the other hand,
have the advantage of continuous operation (Mozia 2010). A wide range of organic,
inorganic, and metallic materials were used to prepare photocatalytic membranes. In
this respect, the most popular organic materials used to prepare photocatalytic
membranes are polyamide, polyethersulfone, polyvinylidene fluoride, polyurethane,
polyethylene terephthalate, polyacrylonitrile, and polytetrafluoroethylene (Argurio
et al. 2018). The most common materials used to prepare ceramic photocatalytic
membranes are aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ), zirconium dioxide (ZrO 2 ), silicon dioxide (SiO 2 ), and some mixes between them (Teik-Thye and
Ron 2016).
Advanced oxidation processes have a number of advantages in the wastewater
treatment, namely:
• High degradation rates of organic compounds from aqueous phase, without
transferring pollutants into another phase.
• High reactivity of OH• radicals that react with almost all pollutants from water.
• During oxidation processes, heavy metals could precipitate as hydroxides and can
be removed in a subsequent stage.
• OH• radicals facilitate the disinfection during the wastewater/water treatment
simultaneously with the organic compounds’ degradation.
• Theoretically, no other new organic compounds with higher toxicity are
produced.
13 Photocatalytic Degradation of Chlorophenols and Antibiotics from Wastewater
417