378
Although commercial activated carbon is most preferable as adsorbent in dye treatment, its application is restricted as it is very expensive.
So, the increasing demand for finding inexpensive and effective treatment
method forces to develop and look for more efficient low-cost adsorbents in dye
removal from industrial effluent. Therefore, different low-cost adsorbents like naturally obtained material, industrial and agricultural waste or by-product, as well as
synthesized product from low cost material and its applications in water treatment
have been compiled here. These adsorbents have been studied to remove various
types of dyes ranging from 80 to 99.9%. In addition, the other conventional treatment methods for dye removal from various wastewaters are also described in brief.
Keywords Dye removal · Industrial effluent · Techniques · Low-cost adsorbent ·
Synthesized products
15.1 Introduction
Among the consequences of the expeditious growth of science and technology,
environmental concerns have become the universal attention for last few years with
the substantial pollution problems like global warming as well as water pollution
(Makertihartha et al. 2017; Gupta and Suhas 2009). Due to the instantaneous
enlargement of industrialization, huge amount of effluents are discharged from the
individual industries which causes significant threats to environment for the adverse
consequences of the pollutants (Ahmad et al. 2015). Among the numerous types of
pollutants, one of the significant groups of pollutant is dye, which is more stable in
water and problematic for biodegradation due to their synthetic origin and compound structure of molecules (Gupta and Suhas 2009). India has been discovered as
explorer in the art of dyeing and considered as one the world’s 12 megadiverse
countries with more than 450 dye plants. The estimated worldwide annual production of dyes is over 7 × 10
5
tons with above 100,000 commercially available dyes
among which approximately15% of dyes are lost during the making and handling
operations and 20% of lost dyes come with industrial effluents (Hai et al. 2007; Rai
et al. 2005; Kanawade and Gaikwad 2013; Demirbas 2009). Significant number of
applications of dyes has been found in several industries including, textile, paper
and pulp, tannery, plastic, paint, rubber, dyestuffs, and electroplating industries.
Among them, the prime consumer of dyes is textile industry that is responsible for
producing substantial volume and complexity of colored effluents (Ahmad et al.
2015; Crini 2006; Demirbas 2009). Dyes are also used in pharmaceutical, food,
cosmetic, and petroleum industries as additives (Husain 2010).
Fundamentally, dyes are the organic compounds consisting with a compound
aromatic structure of molecules for the radiant and firm color to the materials, which
is problematic for biodegradation (Mondal 2008). Dyes are divided into two categories, (1) natural dyes and (2) synthetic dyes. Synthetic dyes are mainly employed in
M. Sardar et al.
Although commercial activated carbon is most preferable as adsorbent in dye treatment, its application is restricted as it is very expensive.
So, the increasing demand for finding inexpensive and effective treatment
method forces to develop and look for more efficient low-cost adsorbents in dye
removal from industrial effluent. Therefore, different low-cost adsorbents like naturally obtained material, industrial and agricultural waste or by-product, as well as
synthesized product from low cost material and its applications in water treatment
have been compiled here. These adsorbents have been studied to remove various
types of dyes ranging from 80 to 99.9%. In addition, the other conventional treatment methods for dye removal from various wastewaters are also described in brief.
Keywords Dye removal · Industrial effluent · Techniques · Low-cost adsorbent ·
Synthesized products
15.1 Introduction
Among the consequences of the expeditious growth of science and technology,
environmental concerns have become the universal attention for last few years with
the substantial pollution problems like global warming as well as water pollution
(Makertihartha et al. 2017; Gupta and Suhas 2009). Due to the instantaneous
enlargement of industrialization, huge amount of effluents are discharged from the
individual industries which causes significant threats to environment for the adverse
consequences of the pollutants (Ahmad et al. 2015). Among the numerous types of
pollutants, one of the significant groups of pollutant is dye, which is more stable in
water and problematic for biodegradation due to their synthetic origin and compound structure of molecules (Gupta and Suhas 2009). India has been discovered as
explorer in the art of dyeing and considered as one the world’s 12 megadiverse
countries with more than 450 dye plants. The estimated worldwide annual production of dyes is over 7 × 10
5
tons with above 100,000 commercially available dyes
among which approximately15% of dyes are lost during the making and handling
operations and 20% of lost dyes come with industrial effluents (Hai et al. 2007; Rai
et al. 2005; Kanawade and Gaikwad 2013; Demirbas 2009). Significant number of
applications of dyes has been found in several industries including, textile, paper
and pulp, tannery, plastic, paint, rubber, dyestuffs, and electroplating industries.
Among them, the prime consumer of dyes is textile industry that is responsible for
producing substantial volume and complexity of colored effluents (Ahmad et al.
2015; Crini 2006; Demirbas 2009). Dyes are also used in pharmaceutical, food,
cosmetic, and petroleum industries as additives (Husain 2010).
Fundamentally, dyes are the organic compounds consisting with a compound
aromatic structure of molecules for the radiant and firm color to the materials, which
is problematic for biodegradation (Mondal 2008). Dyes are divided into two categories, (1) natural dyes and (2) synthetic dyes. Synthetic dyes are mainly employed in
M. Sardar et al.