very in demand because of unendurability. Therefore, another type of dye which is
synthetic organic dye became popular because of its lasting color pay-off and wide
range of colors. Table 1.6 shows the examples of synthetic organic dyes. Synthetic
organic dyes are manufactured from organic molecules. The resources for the synthesis of these dyes are chemicals, by-products of petroleum, and earth minerals
(Ziarani et al. 2018).
Nevertheless, the disadvantage of dyes is not all of the dyes are eco-friendly,
especially, synthetic organic dyes. Most of these dyes are very complex molecules,
extremely toxic, chemical stability, and slow degradation (Reddy and Mohan 2016).
Therefore, the discharge of organic dye containing in water is troublesome the
environment, not only bad vision because of their color but also reduction of sunlight
transmission (Crini and Badot 2008; Dinçer et al. 2007; Zhou et al. 2019). Moreover,
these organic dyes also come with a risk substance, for instance, heavy metal (Zn,
Pb, Cu, Cd, Co), amines, and aromatic compound (Zollinger 2003; Zhou et al.
2019). Therefore, these organic dyes are not only harmful to aquatic life but also
mutagenic to humans. The health problems related to organic dyes are skin irritation,
sneezing, sore eyes, carcinogenicity, dysfunction, and mutagenicity, including the
brain, liver, kidney, central nervous and reproductive system, and others (Zhou et al.
2019).
Presently, many researchers have been found and develop the solutions to treat
organic dyes in water, for example, advanced oxidation processes (Andreozzi et al.
1999; Ikehata et al. 2008), adsorption (Wu et al. 2001; Noll 1991), electro-oxidation
(Särkkä et al. 2015; Recio et al. 2011), and reverse osmosis (Bodalo-Santoyo et al.
2003; Agenson et al. 2003). The solutions to treat these dyes are a challenging issue
due to their high solubility and high persistence in the environment. Photocatalytic
process is one of the interesting solutions for wastewater treatment because this
process is non-toxic and it does not affect human life. Homogeneous or heterogeneous catalysts can be used as photocatalysts for the treatment of organic dyes in
water (Mao et al. 2017; Bodson et al. 2016; Zhang et al. 2017; Mudassir et al. 2018;
Qu et al. 2017).
Table 1.5 (continued)
Annex
Persistent organic pollutant
Group
Polychlorinated dibenzo-pdioxins
Unintentional
production
Polychlorinated dibenzofurans
Unintentional
production
Polychlorinated naphthalenes
Unintentional
production
1 Photocatalytic Remediation of Organic Pollutants in Water
21
synthetic organic dye became popular because of its lasting color pay-off and wide
range of colors. Table 1.6 shows the examples of synthetic organic dyes. Synthetic
organic dyes are manufactured from organic molecules. The resources for the synthesis of these dyes are chemicals, by-products of petroleum, and earth minerals
(Ziarani et al. 2018).
Nevertheless, the disadvantage of dyes is not all of the dyes are eco-friendly,
especially, synthetic organic dyes. Most of these dyes are very complex molecules,
extremely toxic, chemical stability, and slow degradation (Reddy and Mohan 2016).
Therefore, the discharge of organic dye containing in water is troublesome the
environment, not only bad vision because of their color but also reduction of sunlight
transmission (Crini and Badot 2008; Dinçer et al. 2007; Zhou et al. 2019). Moreover,
these organic dyes also come with a risk substance, for instance, heavy metal (Zn,
Pb, Cu, Cd, Co), amines, and aromatic compound (Zollinger 2003; Zhou et al.
2019). Therefore, these organic dyes are not only harmful to aquatic life but also
mutagenic to humans. The health problems related to organic dyes are skin irritation,
sneezing, sore eyes, carcinogenicity, dysfunction, and mutagenicity, including the
brain, liver, kidney, central nervous and reproductive system, and others (Zhou et al.
2019).
Presently, many researchers have been found and develop the solutions to treat
organic dyes in water, for example, advanced oxidation processes (Andreozzi et al.
1999; Ikehata et al. 2008), adsorption (Wu et al. 2001; Noll 1991), electro-oxidation
(Särkkä et al. 2015; Recio et al. 2011), and reverse osmosis (Bodalo-Santoyo et al.
2003; Agenson et al. 2003). The solutions to treat these dyes are a challenging issue
due to their high solubility and high persistence in the environment. Photocatalytic
process is one of the interesting solutions for wastewater treatment because this
process is non-toxic and it does not affect human life. Homogeneous or heterogeneous catalysts can be used as photocatalysts for the treatment of organic dyes in
water (Mao et al. 2017; Bodson et al. 2016; Zhang et al. 2017; Mudassir et al. 2018;
Qu et al. 2017).
Table 1.5 (continued)
Annex
Persistent organic pollutant
Group
Polychlorinated dibenzo-pdioxins
Unintentional
production
Polychlorinated dibenzofurans
Unintentional
production
Polychlorinated naphthalenes
Unintentional
production
1 Photocatalytic Remediation of Organic Pollutants in Water
21