The Comparison of Photocatalytic Degradation and Decolorization Processes of Dyeing Effluents

Table 3

The results of the treatment of dye effluents.

			Dyes degradation after		Reduction of color
Effluent	𝜆max (nm)	Photocatalytic system	60 min of irradiation		In the photocatalytic process		In the physical  processes; Y (%)	Total decolorization of effluents at 𝜆max	COD removal after 300 min
					after 60 min of irradiation			Total (%)	of irradiation 𝑅COD (%)
			X (%)	𝑘𝑋 (min^−1)	Z (%)	𝑘𝑍 (min^−1)
		FeCl3	~0	~0	2	~0	−606	−593
	340	TiO2	37	0.008 ± 0.002	26	0.006 ± 0.002	3	28
		TiO2/FeCl3	10	0.002 ± 0.001	78	0.024 ± 0.003	−347	1
		FeCl3	~0	~0	~0	~0	−147	−155
	430	TiO2	58	0.014 ± 0.003	36	0.008 ± 0.002	4	40
WPac		TiO2/FeCl3	17	0.003 ± 0.002	49	0.010 ± 0.002	−76	11	~0.14.9^a
		FeCl3	~0	~0	~0	~0	−17	−20
	540	TiO2	86	0.030 ± 0.005	57	0.014 ± 0.002	3	58
		TiO2/FeCl3	40	0.008 ± 0.002	22	0.004 ± 0.001	−7	17
		FeCl3	n.d.^b	n.d.	3	~0	4	7
	610	TiO2	n.d.	n.d.	83	0.030 ± 0.004	4	84
		TiO2/FeCl3	n.d.	n.d.	35	0.006 ± 0.002	11	42
		FeCl3	~0	~0	~0	~0	95	95
	510	TiO2	24 (63)^c	0.004 ± 0.002	11	0.002 ± 0.000	14	24
WLeat		TiO2/FeCl3	~30 (100)^c	0.005 ± 0.001	11	0.002 ± 0.001	95	95	~0.40.15^a
		FeCl3	n.d.	n.d.	~0	~0	100	100
	620	TiO2	n.d.	n.d.	21	0.003 ± 0.001	18	36
		TiO2/FeCl3	n.d.	n.d.	100	—	96	100
		FeCl3	~0^e	~0	10	<0.001	50	53	~0
WFlax	350^d	TiO2	10^e	0.001 ± 0.001	22	0.003 ± 0.002	~0	22	−40
		TiO2/FeCl3	35 ÷ 42^e	0.008 ± 0.002	50	0.011 ± 0.003	33	66	−33
		FeCl3	~0 (0)^c	~0	~0^c	~0	96	96^c	~0
WCot	480	TiO2	~0 (5)^c	~0	5^c	~0	~0	5^c	11
		TiO2/FeCl3	~0 (5)^c	~0	5^c	~0	97	96^c	7

^aIn the presence of FeCl₃, TiO₂, and TiO₂/FeCl₃, respectively, ^bno data, ^cafter 300 min of UV-a iradiation, ^dabsorption band without clear maximum, ^ebased on the peak area measurement at 480 nm using HPLC method.