Solutions of the dyes Acid Red 17 (Khataee et al. 2010), Basic Red 46 (Zarei et al.
2010), Acid Yellow 36 (Khataee et al. 2012), Direct Red 23 (Khataee et al. 2013),
and Direct Yellow 12 (Khataee and Zarei 2011), as well as phenol (Khataee et al.
2014), in 0.05 M Na 2 SO 4 with 0.1–0.2 mM Fe
3+ at pH 3.0 were comparatively
treated by the individual processes to show the benefits of the hybrid
PEF/photocatalysis treatment. For example, for 2 L of 50 mg/L Direct Yellow
12 with 0.1 mM Fe
3+ treated for 90 min at 100 mA under a 6 W UVC light
irradiation (Khataee and Zarei 2011), the decolorization ability decreased as follows:
PEF/photocatalysis (93%) > PEF (69%) > EF (56%), being much lower (39%) for
photocatalysis alone (ZnO irradiated by UVC). The high mineralization power of the
Table 11.3 Selected results obtained for the PEC/EF and PEC/PEF treatment of several organics
using undivided cells with nanostructured photoanodes
Photoanode,
cathode
Substrate
Experimental remarks
Best performance Ref.
PEC/EF treatment
TiO 2 /Ti, GF
a
2,4Dichlorophenol
50 mL of 15 mg/L substrate
in 0.02 M Na 2 SO 4 , pH 3.0,
8 W UVA lamp, I ¼ 3.1 mA
93% substrate and
78% TOC
removal
(60 min)
Li et al.
(2007)
TiO 2 /SS
b
,
graphite
Orange G
200 mL of 64 mg/L dye in
0.01 M Na 2 SO 4 , pH ¼ 3.0,
330 μW/cm
2 UVA lamp,
E anod ¼ 1.0 V/SCE
64% TOC
removal (210 min)
Lin et al.
(2013)
Bi 2 WO 6 ,
Fe@Fe 2 O 3 /
ACF
Rhodamine B
100 mL of 10 μM dye in
0.05 M Na 2 SO 4 , pH 6.2,
300 W tungsten halogen
lamp, I ¼ 0.3 mA
94% TOC decay
(240 min)
Ding
et al.
(2012)
Pt/TiO 2 NTs,
GDE
Acid Red 29
500 mL of 85.4 mg/L dye in
0.05 M Na 2 SO 4 , 0.50 mM
Fe
2+ , pH ¼ 3.0, 80 W UVA
lamp,
E anod ¼ 2.0 V vs. Ag/AgCl
100% color
removal
(7 min), 98% TOC
decay (200 mA h/
L
À1
)
Almeida
et al.
(2014)
TiO 2 /FTO
c ,
carbon felt
Phenol
200 mL of 1.4 mM substrate
in 0.05 M K 2 SO 4 , 0.1 mM
Fe
2+ , pH ¼ 3.0, 6 W UVA
lamp, I ¼ 50 mA
67% substrate
decay (300 min),
76% TOC
removal (480 min)
Mousset
et al.
(2017b)
PEC/PEF treatment
TiO 2 /FTO
c ,
carbon felt
Phenol
200 mL of 1.4 mM substrate
in 0.05 M K 2 SO 4 , 0.1 mM
Fe
2+ , pH ¼ 3.0, 6 W UVA
lamp, I ¼ 50 mA
100% substrate
decay (300 min),
97% TOC
removal (480 min)
Mousset
et al.
(2017b)
Pt/TiO 2 NTs,
GDE
Orange G
500 mL of 85.4 mg/L dye in
0.05 M Na 2 SO 4 , 0.50 mM
Fe
2+ , pH ¼ 3.0, 80 W UVA
lamp, I ¼ 50 mA
100% color
removal (30 min),
97% TOC decay
(200 mA h/L)
Almeida
et al.
(2015)
a Second Fe anode at I ¼ 0.1 mA as Fe
2+ source.
b SS—stainless steel, which acts as the source of an
Fe
2+ catalyst.
c FTO—fluorine-doped tin oxide
274
I. Sirés and E. Brillas
2010), Acid Yellow 36 (Khataee et al. 2012), Direct Red 23 (Khataee et al. 2013),
and Direct Yellow 12 (Khataee and Zarei 2011), as well as phenol (Khataee et al.
2014), in 0.05 M Na 2 SO 4 with 0.1–0.2 mM Fe
3+ at pH 3.0 were comparatively
treated by the individual processes to show the benefits of the hybrid
PEF/photocatalysis treatment. For example, for 2 L of 50 mg/L Direct Yellow
12 with 0.1 mM Fe
3+ treated for 90 min at 100 mA under a 6 W UVC light
irradiation (Khataee and Zarei 2011), the decolorization ability decreased as follows:
PEF/photocatalysis (93%) > PEF (69%) > EF (56%), being much lower (39%) for
photocatalysis alone (ZnO irradiated by UVC). The high mineralization power of the
Table 11.3 Selected results obtained for the PEC/EF and PEC/PEF treatment of several organics
using undivided cells with nanostructured photoanodes
Photoanode,
cathode
Substrate
Experimental remarks
Best performance Ref.
PEC/EF treatment
TiO 2 /Ti, GF
a
2,4Dichlorophenol
50 mL of 15 mg/L substrate
in 0.02 M Na 2 SO 4 , pH 3.0,
8 W UVA lamp, I ¼ 3.1 mA
93% substrate and
78% TOC
removal
(60 min)
Li et al.
(2007)
TiO 2 /SS
b
,
graphite
Orange G
200 mL of 64 mg/L dye in
0.01 M Na 2 SO 4 , pH ¼ 3.0,
330 μW/cm
2 UVA lamp,
E anod ¼ 1.0 V/SCE
64% TOC
removal (210 min)
Lin et al.
(2013)
Bi 2 WO 6 ,
Fe@Fe 2 O 3 /
ACF
Rhodamine B
100 mL of 10 μM dye in
0.05 M Na 2 SO 4 , pH 6.2,
300 W tungsten halogen
lamp, I ¼ 0.3 mA
94% TOC decay
(240 min)
Ding
et al.
(2012)
Pt/TiO 2 NTs,
GDE
Acid Red 29
500 mL of 85.4 mg/L dye in
0.05 M Na 2 SO 4 , 0.50 mM
Fe
2+ , pH ¼ 3.0, 80 W UVA
lamp,
E anod ¼ 2.0 V vs. Ag/AgCl
100% color
removal
(7 min), 98% TOC
decay (200 mA h/
L
À1
)
Almeida
et al.
(2014)
TiO 2 /FTO
c ,
carbon felt
Phenol
200 mL of 1.4 mM substrate
in 0.05 M K 2 SO 4 , 0.1 mM
Fe
2+ , pH ¼ 3.0, 6 W UVA
lamp, I ¼ 50 mA
67% substrate
decay (300 min),
76% TOC
removal (480 min)
Mousset
et al.
(2017b)
PEC/PEF treatment
TiO 2 /FTO
c ,
carbon felt
Phenol
200 mL of 1.4 mM substrate
in 0.05 M K 2 SO 4 , 0.1 mM
Fe
2+ , pH ¼ 3.0, 6 W UVA
lamp, I ¼ 50 mA
100% substrate
decay (300 min),
97% TOC
removal (480 min)
Mousset
et al.
(2017b)
Pt/TiO 2 NTs,
GDE
Orange G
500 mL of 85.4 mg/L dye in
0.05 M Na 2 SO 4 , 0.50 mM
Fe
2+ , pH ¼ 3.0, 80 W UVA
lamp, I ¼ 50 mA
100% color
removal (30 min),
97% TOC decay
(200 mA h/L)
Almeida
et al.
(2015)
a Second Fe anode at I ¼ 0.1 mA as Fe
2+ source.
b SS—stainless steel, which acts as the source of an
Fe
2+ catalyst.
c FTO—fluorine-doped tin oxide
274
I. Sirés and E. Brillas