316
12.4 Boron Sources and Industrial Applications
There are at least 200 types of boron mineral in the nature. Especially, borax, kernite, colemanite, and ulexite are the widely used boron minerals (Lyday 2000). Boron
content in soils changes according to the type of soil and pH. Boron that is contained in the water comes from boron-containing soil and minerals (Parks and
Edwards 2005; Gupta et al. 2008). Boron can also be found in the atmosphere due
to volcanic activities and geothermal sources (Coughlin 1998). Oceans have
4.6 mg L
−1
boron, and the atmosphere also contains boron due to the evaporation
process of the water (Anderson and Kitto 1994). Raining may cause the increase of
boron concentration in drinking water. These are the natural ways how boron may
contain in drinking water.
Boron is used for laboratory glassware, aircraft glass, window glass, optical
glass, plastics, and fiberglass in automobile and aircraft industries. Due to its lightweight, low price, and resistance to stress and to chemical effects, boron is used
widely in industrial applications. It also gives hardness and durability to the materials used.
12.5 Adsorption
Adsorption is one of the efficient treatment methods for the purification of water.
Adsorption is basically the interaction of adsorbate molecules (gas or liquid) with
the adsorbent surface (solid). It is defined as the increase of the concentration on a
substance surface (Thomas and Crittenden 1998). Electrostatic interaction between
adsorbent and adsorbate molecules takes place via van der Waals interaction or
chemical interaction. Using efficient and low-cost adsorbent is the key point of the
adsorption process (Kong et al., 2017).
12.5.1 Clay Minerals
Clay minerals are the natural sources that can be used for adsorption process.
Various types of clay minerals exist in the nature such as kaolinite group, smectite
group, illite group, and chloride group.
Montmorillonite has 2:1 sheet structure, which means one octahedral sheet is
placed between two tetrahedral sheets. Keren et al. (1981) studied the boron adsorption of montmorillonite clay. Montmorillonite clay was used in homoionic form.
Sodium was used to change the surface charge from negative to positive form.
Na-montmorillonite was an effective adsorbent at higher pH values. The maximum
adsorption capacity was achieved at pH 9.3. This result was due to the ionic type of
boron changing according to solution pH. Borate ion (B(OH) 4
−
) dominates in the
P. Demircivi
12.4 Boron Sources and Industrial Applications
There are at least 200 types of boron mineral in the nature. Especially, borax, kernite, colemanite, and ulexite are the widely used boron minerals (Lyday 2000). Boron
content in soils changes according to the type of soil and pH. Boron that is contained in the water comes from boron-containing soil and minerals (Parks and
Edwards 2005; Gupta et al. 2008). Boron can also be found in the atmosphere due
to volcanic activities and geothermal sources (Coughlin 1998). Oceans have
4.6 mg L
−1
boron, and the atmosphere also contains boron due to the evaporation
process of the water (Anderson and Kitto 1994). Raining may cause the increase of
boron concentration in drinking water. These are the natural ways how boron may
contain in drinking water.
Boron is used for laboratory glassware, aircraft glass, window glass, optical
glass, plastics, and fiberglass in automobile and aircraft industries. Due to its lightweight, low price, and resistance to stress and to chemical effects, boron is used
widely in industrial applications. It also gives hardness and durability to the materials used.
12.5 Adsorption
Adsorption is one of the efficient treatment methods for the purification of water.
Adsorption is basically the interaction of adsorbate molecules (gas or liquid) with
the adsorbent surface (solid). It is defined as the increase of the concentration on a
substance surface (Thomas and Crittenden 1998). Electrostatic interaction between
adsorbent and adsorbate molecules takes place via van der Waals interaction or
chemical interaction. Using efficient and low-cost adsorbent is the key point of the
adsorption process (Kong et al., 2017).
12.5.1 Clay Minerals
Clay minerals are the natural sources that can be used for adsorption process.
Various types of clay minerals exist in the nature such as kaolinite group, smectite
group, illite group, and chloride group.
Montmorillonite has 2:1 sheet structure, which means one octahedral sheet is
placed between two tetrahedral sheets. Keren et al. (1981) studied the boron adsorption of montmorillonite clay. Montmorillonite clay was used in homoionic form.
Sodium was used to change the surface charge from negative to positive form.
Na-montmorillonite was an effective adsorbent at higher pH values. The maximum
adsorption capacity was achieved at pH 9.3. This result was due to the ionic type of
boron changing according to solution pH. Borate ion (B(OH) 4
−
) dominates in the
P. Demircivi