day-to-day and area-to-area variation of solar light intensity (Kabir et al. 2018).
Therefore this is not authentic for an area with unsustainable climate or atmospheric
conditions.
11.3 Solar Energy Application in Wastewater Treatment
From the last few decades, the mechanism of solar energy utilization along with the
combination of heterogeneous catalysis to treat wastewater has gained considerable
attraction for many researchers; such process is known as photocatalysis which is a
kind of advanced oxidation processes.
Numerous reports have been published conferring the various application and
mechanism of photocatalysis with a favourable laboratory and pilot-plant-based
studies, and most of these studies have discussed the detailed, complex reaction
mechanisms of photodegradation of many organic and inorganic pollutant present in
wastewater (Ollis and Turchi 1990; Kisch and Twardzik 1991; Künneth et al. 1993;
Vidal et al. 1994; Herrmann 1995; Serpone 1995; Serpone et al. 1996; Peral et al.
1997; Kemeny et al. 2000; Botta et al. 2002; Ustinovich et al. 2005; Doll and
Frimmel 2005; Gonçalves et al. 2005; Augugliaro et al. 2006; Sirtori et al. 2006;
Guo and Hu 2007; Bayarri et al. 2007; Palmisano et al. 2007; Robert 2007; Sadik
et al. 2007; Fujishima et al. 2007; Kiliç and Çinar 2008; Lair et al. 2008; Rodrigues
et al. 2008; Chen et al. 2008; Du et al. 2008; Augugliaro and Palmisano 2010; Kisch
2010; Shan et al. 2010; Bickley 2010; Khataee et al. 2011; Valencia et al. 2011;
Wang et al. 2011b; Xiong et al. 2011). Hence, these studies support the possibility of
complete degradation of pollutant through solar photocatalysis.
11.4 Nature of Tannery Effluent
Extensive volume of water and pollutants, which has an adverse effect on the
environment, is released during the tanning operations. Table 11.1 (Dixit et al.
2015) illustrates the details of the wastewater and characteristics of pollutants
generated throughout the various tanning process.
Mostly the tannery wastewater is of dark brown in colour, possessing a strong
odour with a large chemical oxygen demand, biochemical oxygen demand, total
dissolved solids, chrome and a phenolic compound which has an adverse effect on
the environment (Kusturica et al. 2015). Even after conventional treatment processes, there is a difficulty to remove them, and approximately 90% of total tannery
pollution results from traditional tanning and pre-tanning processes. These processes
cause an increment of chemical oxygen demand, sulphates, chlorides and total
dissolved solids with a variation in potential of hydrogen (Dixit et al. 2015). The
usage of lime with sodium sulphite in the liming process contributes to 92%
362
A. Tripathi and S. Narayanan
Therefore this is not authentic for an area with unsustainable climate or atmospheric
conditions.
11.3 Solar Energy Application in Wastewater Treatment
From the last few decades, the mechanism of solar energy utilization along with the
combination of heterogeneous catalysis to treat wastewater has gained considerable
attraction for many researchers; such process is known as photocatalysis which is a
kind of advanced oxidation processes.
Numerous reports have been published conferring the various application and
mechanism of photocatalysis with a favourable laboratory and pilot-plant-based
studies, and most of these studies have discussed the detailed, complex reaction
mechanisms of photodegradation of many organic and inorganic pollutant present in
wastewater (Ollis and Turchi 1990; Kisch and Twardzik 1991; Künneth et al. 1993;
Vidal et al. 1994; Herrmann 1995; Serpone 1995; Serpone et al. 1996; Peral et al.
1997; Kemeny et al. 2000; Botta et al. 2002; Ustinovich et al. 2005; Doll and
Frimmel 2005; Gonçalves et al. 2005; Augugliaro et al. 2006; Sirtori et al. 2006;
Guo and Hu 2007; Bayarri et al. 2007; Palmisano et al. 2007; Robert 2007; Sadik
et al. 2007; Fujishima et al. 2007; Kiliç and Çinar 2008; Lair et al. 2008; Rodrigues
et al. 2008; Chen et al. 2008; Du et al. 2008; Augugliaro and Palmisano 2010; Kisch
2010; Shan et al. 2010; Bickley 2010; Khataee et al. 2011; Valencia et al. 2011;
Wang et al. 2011b; Xiong et al. 2011). Hence, these studies support the possibility of
complete degradation of pollutant through solar photocatalysis.
11.4 Nature of Tannery Effluent
Extensive volume of water and pollutants, which has an adverse effect on the
environment, is released during the tanning operations. Table 11.1 (Dixit et al.
2015) illustrates the details of the wastewater and characteristics of pollutants
generated throughout the various tanning process.
Mostly the tannery wastewater is of dark brown in colour, possessing a strong
odour with a large chemical oxygen demand, biochemical oxygen demand, total
dissolved solids, chrome and a phenolic compound which has an adverse effect on
the environment (Kusturica et al. 2015). Even after conventional treatment processes, there is a difficulty to remove them, and approximately 90% of total tannery
pollution results from traditional tanning and pre-tanning processes. These processes
cause an increment of chemical oxygen demand, sulphates, chlorides and total
dissolved solids with a variation in potential of hydrogen (Dixit et al. 2015). The
usage of lime with sodium sulphite in the liming process contributes to 92%
362
A. Tripathi and S. Narayanan