3.1 Physical Treatment Methods
In the physical treatment methods, separation of particles is achieved through
electrical attraction, gravity sedimentation, dispersion, or physical barriers forces.
These methods do not hinder the chemical structure of the pollutants present in the
wastewaters but only effect changes in the physical state (Crini et al. 2019).
Adsorption is one of the efficient physical methods to treat wastewaters. In the
adsorption, activated carbon, silicon polymers, and kaolin are the most studied and
proven to be potential adsorbents that have appreciable ability to adsorb various dyes
(Bizuneh 2012). Physical adsorption occurs when the adsorbent has an unstable
interspecies bond, while the chemical adsorption occurs when the electron
exchanges are observed to be strong between the interspecies (Ahmad and Mondal
2009). Recently, adsorption has been modernized using novel adsorbents, such as
eggshells, sugar cane bagasse, silica gel, almond peel, etc. (Ellis et al. 2012, Dotto
et al. 2019). Coagulation and flocculation are the treatments that are normally used to
remove the organic matter, but there are no effects on the removal of soluble dyes.
However, this method effectively removes insoluble colors (Lin and Lin 1993). The
applicability of chemical methods is doubtful because of its high operating cost and
restrictions on disposal of endpoint sludge. Nowadays, ozone wastewater treatment
using ozone oxidization is proven to be an effective methodology for textile wastewater treatment (Langlais et al. 1991). During this treatment, ozone specifically
attacks the bestow color double bonds to decolorize the effluents. However, several
reports documented that the substantial reduction in COD could not be resulted by
ozonation (Coste et al. 1996, Adams et al. 1995). Moreover, additional costs may
apply for installation of ozonation unit (Kurniawan et al. 2006). Another salient
approach, membrane filtration, is widely studied method and well developed for an
efficient removal of dyes. This approach has been proven to be cost-effective and
less water consumption (Chang 2014). In addition to the elimination of BOD and
COD, it has unique features, such as appreciable tolerance against temperature and
harmful toxic gases. However, it’s expensiveness, risk on clogging, and membrane
replacement hinder its practical applicability (Srivastava et al. 2015).
3.2 Chemical Treatment Methods
Chemicals play a very important role in accelerating wastewater disinfection and
treatment process. Some organic compounds are used together with physical and
biological processes. They involve appropriate methods, such as chemical precipitation, coagulation and flocculation, and chemical oxidation. Chemical precipitation
is one of the most extensively used methods for textile wastewater treatment.
Dissolved toxic metals can be removed successfully through this method. Precipitation reaction can be triggered by adding precipitation reagents that make solubilized metals to form agglomerated solid particles and are subsequently removed by
10 A Harmless Approach on Textile Effluent Detoxification: Bioremediation and. . .
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In the physical treatment methods, separation of particles is achieved through
electrical attraction, gravity sedimentation, dispersion, or physical barriers forces.
These methods do not hinder the chemical structure of the pollutants present in the
wastewaters but only effect changes in the physical state (Crini et al. 2019).
Adsorption is one of the efficient physical methods to treat wastewaters. In the
adsorption, activated carbon, silicon polymers, and kaolin are the most studied and
proven to be potential adsorbents that have appreciable ability to adsorb various dyes
(Bizuneh 2012). Physical adsorption occurs when the adsorbent has an unstable
interspecies bond, while the chemical adsorption occurs when the electron
exchanges are observed to be strong between the interspecies (Ahmad and Mondal
2009). Recently, adsorption has been modernized using novel adsorbents, such as
eggshells, sugar cane bagasse, silica gel, almond peel, etc. (Ellis et al. 2012, Dotto
et al. 2019). Coagulation and flocculation are the treatments that are normally used to
remove the organic matter, but there are no effects on the removal of soluble dyes.
However, this method effectively removes insoluble colors (Lin and Lin 1993). The
applicability of chemical methods is doubtful because of its high operating cost and
restrictions on disposal of endpoint sludge. Nowadays, ozone wastewater treatment
using ozone oxidization is proven to be an effective methodology for textile wastewater treatment (Langlais et al. 1991). During this treatment, ozone specifically
attacks the bestow color double bonds to decolorize the effluents. However, several
reports documented that the substantial reduction in COD could not be resulted by
ozonation (Coste et al. 1996, Adams et al. 1995). Moreover, additional costs may
apply for installation of ozonation unit (Kurniawan et al. 2006). Another salient
approach, membrane filtration, is widely studied method and well developed for an
efficient removal of dyes. This approach has been proven to be cost-effective and
less water consumption (Chang 2014). In addition to the elimination of BOD and
COD, it has unique features, such as appreciable tolerance against temperature and
harmful toxic gases. However, it’s expensiveness, risk on clogging, and membrane
replacement hinder its practical applicability (Srivastava et al. 2015).
3.2 Chemical Treatment Methods
Chemicals play a very important role in accelerating wastewater disinfection and
treatment process. Some organic compounds are used together with physical and
biological processes. They involve appropriate methods, such as chemical precipitation, coagulation and flocculation, and chemical oxidation. Chemical precipitation
is one of the most extensively used methods for textile wastewater treatment.
Dissolved toxic metals can be removed successfully through this method. Precipitation reaction can be triggered by adding precipitation reagents that make solubilized metals to form agglomerated solid particles and are subsequently removed by
10 A Harmless Approach on Textile Effluent Detoxification: Bioremediation and. . .
203