122
S. Lakshmana Prabu et al.
Fig. 5 Adsorption process between the pollutants and adsorbents
2004; Foo and Hameed 2010; Popuri and Guttikonda 2015). The adsorption process
between the pollutants and adsorbents (Patel 2018) are shown in Fig. 5.
2.8 Ozonation
Ozonation technique is preferably used in treating wastewater due to its oxidation
property. At pH 9, it has been considered as an advanced oxidation process. Chemical
reaction between the ozone and the hydroxyl radicals is the main oxidation process
and preferably act on the unsaturated bonds of chromophores [conjugated double
bonds] of the dye. In water, ozone decompose into ozone and radical species. In
ozonation process, either directly or indirectly oxidation can take place (Shriram and
Kanmani 2014).
Direct Direct reaction with the dissolved molecular ozone (O 3 ).
Indirect Indirect reaction with the radical species (HO, HO 2 ).
Factors affecting the ozonation process are
• pH,
• Ozone dose,
• UV radiation,
• concentration of dye,
• Temperature.
2.9 Irradiation
Ionizing radiation is another technique in textile effluent treatment. Gamma rays
is an electromagentic radiation source with high frequency and sufficient energy.
They generate ions by extricating the electrons from atoms and molecules. Further
reaction of ions forms free radicals. This formed free radicals radiolysis the water
S. Lakshmana Prabu et al.
Fig. 5 Adsorption process between the pollutants and adsorbents
2004; Foo and Hameed 2010; Popuri and Guttikonda 2015). The adsorption process
between the pollutants and adsorbents (Patel 2018) are shown in Fig. 5.
2.8 Ozonation
Ozonation technique is preferably used in treating wastewater due to its oxidation
property. At pH 9, it has been considered as an advanced oxidation process. Chemical
reaction between the ozone and the hydroxyl radicals is the main oxidation process
and preferably act on the unsaturated bonds of chromophores [conjugated double
bonds] of the dye. In water, ozone decompose into ozone and radical species. In
ozonation process, either directly or indirectly oxidation can take place (Shriram and
Kanmani 2014).
Direct Direct reaction with the dissolved molecular ozone (O 3 ).
Indirect Indirect reaction with the radical species (HO, HO 2 ).
Factors affecting the ozonation process are
• pH,
• Ozone dose,
• UV radiation,
• concentration of dye,
• Temperature.
2.9 Irradiation
Ionizing radiation is another technique in textile effluent treatment. Gamma rays
is an electromagentic radiation source with high frequency and sufficient energy.
They generate ions by extricating the electrons from atoms and molecules. Further
reaction of ions forms free radicals. This formed free radicals radiolysis the water