colouring components of dyes have the ability to change the turbidity and pH of
water resources and disturb native population (Degs et al. 2000; Karimifard and
Moghaddam 2018; Sharma et al. 2019b).
In addition, the colour component of dyes has the tendency to obstruct light
infiltration and disturb the natural balance of water bodies. The photosynthetic rate
of aquatic plants has also been affected by the presence of colouring dye molecules
in water bodies, thus influencing aquatic inhabitants (Akbari et al. 2020). The
amount of dissolved oxygen in rivers and lakes has also been declined due to the
presence of sulphur containing dyes in aqueous media. The seepage of dyes in deep
soil has produced toxic impact on the quality of underground water. Therefore, dye
waste in industrialized sewages is a direct health hazard to living beings. The
presence of toxic dyes in downstream has made the water unfit for irrigation
(Abouzeid et al. 2019; Chaudhary et al. 2016b; Jadhav et al. 2019). The consumption
of toxic dyes has produced leukaemia, neurological disorders, allergy, respiratory
issues and skin problems. Different types of cancers of liver, kidney, brain and
urinary bladders are caused due to the consumption of toxic water. Not only human
being, but bacterial and mammalians habitants are also affected by dyes (Mazumder
2008; Chaudhary et al. 2016d; Mohod and Dhote 2013). Thus, there is a critical
requirement to develop vigorous, inexpensive, sustainable and environmentally
affable processes to eliminate dyes from waste water.
7.3
Commercially Employed Methodologies for Dye Removal
The excessive released amount of toxic dyes in water resources has produced
immense negative effect on the ecological system and on the deterioration of
water resources. Therefore, the development of effectual schemes for the removal
of dyes from the hydrosphere is crucial (Zhou et al. 2019). Till date, various types of
physical, chemical or biological methodologies are employed for the treatment of
waste water with dyes as main pollutant source (Fig. 7.2).
To name the few, electrochemical processes, coagulation methods, separation
techniques with membranes, flocculation processes, adsorption via charcoals,
ion-exchange techniques, biodegradation methods using bacteria or fungi, advanced
oxidation methods and many more (Hassaan et al. 2017; Kariyajjanavar et al. 2011;
Jinqi and Houtian 1992). The main merits and demerits are listed in Table 7.2.
7.4
Confronting Issues with Commercially Employed
Methodologies
On interpreting the tabulate data in Table 7.2, it has been clearly visualized that the
available methodologies have possessed several shortcomings for the treatment of
dyes. The methodologies are not highly selective towards dye molecules. The
application of different methods on one kind of dyes has provided different degree
of decolouration rate. Several methods have produced lot of side products during the
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S. Chaudhary and P. Chauhan
water resources and disturb native population (Degs et al. 2000; Karimifard and
Moghaddam 2018; Sharma et al. 2019b).
In addition, the colour component of dyes has the tendency to obstruct light
infiltration and disturb the natural balance of water bodies. The photosynthetic rate
of aquatic plants has also been affected by the presence of colouring dye molecules
in water bodies, thus influencing aquatic inhabitants (Akbari et al. 2020). The
amount of dissolved oxygen in rivers and lakes has also been declined due to the
presence of sulphur containing dyes in aqueous media. The seepage of dyes in deep
soil has produced toxic impact on the quality of underground water. Therefore, dye
waste in industrialized sewages is a direct health hazard to living beings. The
presence of toxic dyes in downstream has made the water unfit for irrigation
(Abouzeid et al. 2019; Chaudhary et al. 2016b; Jadhav et al. 2019). The consumption
of toxic dyes has produced leukaemia, neurological disorders, allergy, respiratory
issues and skin problems. Different types of cancers of liver, kidney, brain and
urinary bladders are caused due to the consumption of toxic water. Not only human
being, but bacterial and mammalians habitants are also affected by dyes (Mazumder
2008; Chaudhary et al. 2016d; Mohod and Dhote 2013). Thus, there is a critical
requirement to develop vigorous, inexpensive, sustainable and environmentally
affable processes to eliminate dyes from waste water.
7.3
Commercially Employed Methodologies for Dye Removal
The excessive released amount of toxic dyes in water resources has produced
immense negative effect on the ecological system and on the deterioration of
water resources. Therefore, the development of effectual schemes for the removal
of dyes from the hydrosphere is crucial (Zhou et al. 2019). Till date, various types of
physical, chemical or biological methodologies are employed for the treatment of
waste water with dyes as main pollutant source (Fig. 7.2).
To name the few, electrochemical processes, coagulation methods, separation
techniques with membranes, flocculation processes, adsorption via charcoals,
ion-exchange techniques, biodegradation methods using bacteria or fungi, advanced
oxidation methods and many more (Hassaan et al. 2017; Kariyajjanavar et al. 2011;
Jinqi and Houtian 1992). The main merits and demerits are listed in Table 7.2.
7.4
Confronting Issues with Commercially Employed
Methodologies
On interpreting the tabulate data in Table 7.2, it has been clearly visualized that the
available methodologies have possessed several shortcomings for the treatment of
dyes. The methodologies are not highly selective towards dye molecules. The
application of different methods on one kind of dyes has provided different degree
of decolouration rate. Several methods have produced lot of side products during the
168
S. Chaudhary and P. Chauhan