388
positively charged particles are used in anion exchange membrane that allows passing anions but also rejecting to pass the cations. The major drawbacks are the process is very expensive and also ineffective for disperse dye removal (Ruan
et al. 2019).
Irradiation is very effective and simple technique for dye removal from wastewater
by using radiations obtained from monochromatic ultraviolent lamp. This method
requires a constant and sufficient supply of oxygen because of the requirement of huge
quantity of dissolved oxygen to destroy the organic dye effectively by irradiation. This
is a very cheap process and the dyes can be oxidized easily (Robinson et al. 2001).
Membrane filtration, an advanced technology used for color, salinity, and chemical oxygen demand removal from industrial effluent. Here, the wastewater passes
through the membrane, and the large size solutes are trapped in the membrane
pores. Based on the pore size, membrane filtration can be classified as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis (Gupta and Suhas 2009;
Ahmad et al. 2015). Among all microfiltration is less efficient for waste water treatment due to its large pore size. But ultrafiltration and nanofiltration are very effective for eliminating all kind of dye molecules (Gupta and Suhas 2009). On the other
hand, reverse osmosis is also very efficient in desalting and removing wide range of
dye wastes. The disadvantages are high cost, membrane fouling, and short membrane life, and it cannot be operated at above room temperature (Gupta and Suhas
2009; Holkar et al. 2016). Mo et al. (2008) studied the dye separation using nanofiltration polyamide membrane was almost 100% (Mo et al. 2008).
Adsorption is the most successful and established technology as it offers low
cost, complete removal of dyes, and non-toxic by-product formation (Ruan et al.
2019). Depending on the attachment of adsorbate on the adsorbent surface, adsorption processes are categorized as physical sorption and chemical sorption. In physical adsorption, the adsorbate is attached on adsorbents by weak physical forces like
van der Waals forces, polarity, hydrogen bonding, hydrophobicity, dipole interactions, static interactions, and π–π interactions. In chemical adsorption, adsorbates
are attached on adsorbent surface by the chemically bound of electrons exchange.
The adsorbents generally used in this process are activated carbon, low cost adsorbent, nanoparticle, and other types of adsorbent (Gupta and Suhas 2009; Robinson
et al. 2001). Zhuang et al. (2009) studied high adsorption rates above 99.9% at low
concentration dyes (Zhuang et al. 2009).
15.3.2 Biological Treatment
Biological treatment is one of the most familiar and widespread technology applied
for dye treatment with low cost and eco-friendly nature as it requires no chemical
addition and less amount of energy (Punzi et al. 2015; Ahmad et al. 2015). The
principle of this treatment is that the biodegradable wastes are converted into more
simple and harmless species by using different type of microorganisms. In this process the removal of dye is classified into three groups such as aerobic process (in
M. Sardar et al.
positively charged particles are used in anion exchange membrane that allows passing anions but also rejecting to pass the cations. The major drawbacks are the process is very expensive and also ineffective for disperse dye removal (Ruan
et al. 2019).
Irradiation is very effective and simple technique for dye removal from wastewater
by using radiations obtained from monochromatic ultraviolent lamp. This method
requires a constant and sufficient supply of oxygen because of the requirement of huge
quantity of dissolved oxygen to destroy the organic dye effectively by irradiation. This
is a very cheap process and the dyes can be oxidized easily (Robinson et al. 2001).
Membrane filtration, an advanced technology used for color, salinity, and chemical oxygen demand removal from industrial effluent. Here, the wastewater passes
through the membrane, and the large size solutes are trapped in the membrane
pores. Based on the pore size, membrane filtration can be classified as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis (Gupta and Suhas 2009;
Ahmad et al. 2015). Among all microfiltration is less efficient for waste water treatment due to its large pore size. But ultrafiltration and nanofiltration are very effective for eliminating all kind of dye molecules (Gupta and Suhas 2009). On the other
hand, reverse osmosis is also very efficient in desalting and removing wide range of
dye wastes. The disadvantages are high cost, membrane fouling, and short membrane life, and it cannot be operated at above room temperature (Gupta and Suhas
2009; Holkar et al. 2016). Mo et al. (2008) studied the dye separation using nanofiltration polyamide membrane was almost 100% (Mo et al. 2008).
Adsorption is the most successful and established technology as it offers low
cost, complete removal of dyes, and non-toxic by-product formation (Ruan et al.
2019). Depending on the attachment of adsorbate on the adsorbent surface, adsorption processes are categorized as physical sorption and chemical sorption. In physical adsorption, the adsorbate is attached on adsorbents by weak physical forces like
van der Waals forces, polarity, hydrogen bonding, hydrophobicity, dipole interactions, static interactions, and π–π interactions. In chemical adsorption, adsorbates
are attached on adsorbent surface by the chemically bound of electrons exchange.
The adsorbents generally used in this process are activated carbon, low cost adsorbent, nanoparticle, and other types of adsorbent (Gupta and Suhas 2009; Robinson
et al. 2001). Zhuang et al. (2009) studied high adsorption rates above 99.9% at low
concentration dyes (Zhuang et al. 2009).
15.3.2 Biological Treatment
Biological treatment is one of the most familiar and widespread technology applied
for dye treatment with low cost and eco-friendly nature as it requires no chemical
addition and less amount of energy (Punzi et al. 2015; Ahmad et al. 2015). The
principle of this treatment is that the biodegradable wastes are converted into more
simple and harmless species by using different type of microorganisms. In this process the removal of dye is classified into three groups such as aerobic process (in
M. Sardar et al.