254
Chemical adsorption: In this type, interaction between adsorbent and adsorbate
occurs through chemical reactions by creating new bonds such as covalent and ionic
bond, etc. Adsorption technique has many advantages over other usual methods
such as efficient, effective, regenerative, eco-friendly, and metal selectivity.
Activated carbon materials are undoubtedly popular and commercially used
adsorbents throughout the world because of having large pore size and pore volumes. Nowadays, it becomes very expensive due to its depleted source of coal as
well as needs complex agent to improve its efficiency toward inorganic matter. An
alternate source of activated carbon which is abundant and inexpensive becomes our
prime concern which leads us to the solution that transforms carbonaceous materials into activating carbon for elimination of toxic metals. Many of the researchers
come up with the interest for production of activated carbon from waste materials.
The binary component adsorption of copper and lead by activated carbon produced
from eucalyptus bark was found with maximum adsorption capacities for lead and
copper of 0.53 and 0.45 mmol g
−1
, respectively (Kongsuwan et al. 2009). Poultrybased activated carbon shows higher adsorption efficiency for heavy metals than
commercial activated carbon produced from coal and coconut shell.
10.3 Low-Cost Adsorbent
Most of the abovementioned techniques have many disadvantages such as higher
cost of operation and sludge disposal problem caused by these techniques. But
adsorption is the most efficient technique in wastewater treatment due to the advantages like eco-friendly, cost-effective, simple technique and very less maintenance
required (Bhattacharyya and Gupta 2008).
10.3.1 Zeolite
Zeolites are naturally occurring three-dimensional hydrated aluminosilicate mineral. They belong to the class of minerals known as “tectosilicates.” The structures
formed by the interaction of alumina and silica and are commonly referred as
molecular sieves. The chemical formula of zeolites has been shown below:
M O Al O xSiO yH O
n
2
2 3
2
2
/
.
.
.
where:
M – metal (sodium, lithium, potassium, calcium, and magnesium)
n – valence of metal cation
y – number of water molecules present in zeolite structure
M. Maharana et al.
Chemical adsorption: In this type, interaction between adsorbent and adsorbate
occurs through chemical reactions by creating new bonds such as covalent and ionic
bond, etc. Adsorption technique has many advantages over other usual methods
such as efficient, effective, regenerative, eco-friendly, and metal selectivity.
Activated carbon materials are undoubtedly popular and commercially used
adsorbents throughout the world because of having large pore size and pore volumes. Nowadays, it becomes very expensive due to its depleted source of coal as
well as needs complex agent to improve its efficiency toward inorganic matter. An
alternate source of activated carbon which is abundant and inexpensive becomes our
prime concern which leads us to the solution that transforms carbonaceous materials into activating carbon for elimination of toxic metals. Many of the researchers
come up with the interest for production of activated carbon from waste materials.
The binary component adsorption of copper and lead by activated carbon produced
from eucalyptus bark was found with maximum adsorption capacities for lead and
copper of 0.53 and 0.45 mmol g
−1
, respectively (Kongsuwan et al. 2009). Poultrybased activated carbon shows higher adsorption efficiency for heavy metals than
commercial activated carbon produced from coal and coconut shell.
10.3 Low-Cost Adsorbent
Most of the abovementioned techniques have many disadvantages such as higher
cost of operation and sludge disposal problem caused by these techniques. But
adsorption is the most efficient technique in wastewater treatment due to the advantages like eco-friendly, cost-effective, simple technique and very less maintenance
required (Bhattacharyya and Gupta 2008).
10.3.1 Zeolite
Zeolites are naturally occurring three-dimensional hydrated aluminosilicate mineral. They belong to the class of minerals known as “tectosilicates.” The structures
formed by the interaction of alumina and silica and are commonly referred as
molecular sieves. The chemical formula of zeolites has been shown below:
M O Al O xSiO yH O
n
2
2 3
2
2
/
.
.
.
where:
M – metal (sodium, lithium, potassium, calcium, and magnesium)
n – valence of metal cation
y – number of water molecules present in zeolite structure
M. Maharana et al.