318
Iizuka et al. (2014) used waste concrete particles for boron removal. Efficient
boron removal was not achieved at higher boron concentrations (100–300 mg L
−1
);
however, using 10 mg L
−1
initial boron concentration, boron removal was increased
and was attributed to ion-exchange mechanism (Iizuka et al. 2014).
Palm oil mill boiler (POMB) ash impregnated with various compounds, such as
citric acid, tartaric acid, salicylic acid, etc., was investigated for boron removal. It
was found that the impregnated type was effective on boron adsorption and boron
removal was highly dependent on solution pH (Chieng and Chong 2013).
12.5.3 Oxides, Hydroxides, and Layered Double Hydroxides
Garcia-Soto and Camacho (2006) studied magnesium oxide precipitation/adsorption method on boron removal, and the initial boron solution concentration used was
500 mg L
−1
. As a result of this study, 95% of boron was removed. Borate ion was
adsorbed onto the magnesium oxide surface in aqueous solution. However, a metallic complex occurred between magnesium ions and borate ions in basic medium,
which was performed the precipitation reaction (Garcia-Soto and Camacho 2006).
Öztürk and Kavak (2008) used cerium oxide as the adsorbent for boron removal.
Statistical analysis was done to the experimental data by choosing the temperature,
solution pH, and particle type as the parameters. All the parameters have positive
effect on boron removal. However, temperature has the greatest effect on the removal
of boron. Langmuir isotherm model was fitted well the experimental data (Öztürk
and Kavak 2008).
Demetriou and Pashalidis (2012) studied boron removal from aqueous solution
using iron oxide. Experimental data showed that the adsorption mechanism depends
on the replacement of a water molecule by a boric acid molecule. Maximum adsorption capacity was achieved as 0.03 mol kg
−1
according to Langmuir isotherm model
(Demetriou and Pashalidis 2012).
Sub-micron calcium hydroxide particles were used for boron adsorption.
Modified sub-micron calcium hydroxide particles improved adsorption efficiency
compared with unmodified calcium hydroxide. The adsorption efficiency was
increased from 67.2% to 76.2% at the same experimental conditions (Tsai and
Lo 2015).
Prodromou (2004a, b) studied boron removal using amorphous aluminum
hydroxides. Boron adsorption was affected by the type of acids exist in the soil.
Boron adsorption increased according to the complexion reaction with the acids.
Maximum boron adsorption occurred around 76%, and Freundlich isotherm model
was the best isotherm model fitted the experimental data (Prodromou 2004a, b).
Freshly prepared magnesium hydroxide has the highest specific surface area.
Therefore, Prodromou (2004a, b) used fresh magnesium hydroxide to adsorb boron
from the aqueous solution. Complexation reaction occurs between magnesium
P. Demircivi
Iizuka et al. (2014) used waste concrete particles for boron removal. Efficient
boron removal was not achieved at higher boron concentrations (100–300 mg L
−1
);
however, using 10 mg L
−1
initial boron concentration, boron removal was increased
and was attributed to ion-exchange mechanism (Iizuka et al. 2014).
Palm oil mill boiler (POMB) ash impregnated with various compounds, such as
citric acid, tartaric acid, salicylic acid, etc., was investigated for boron removal. It
was found that the impregnated type was effective on boron adsorption and boron
removal was highly dependent on solution pH (Chieng and Chong 2013).
12.5.3 Oxides, Hydroxides, and Layered Double Hydroxides
Garcia-Soto and Camacho (2006) studied magnesium oxide precipitation/adsorption method on boron removal, and the initial boron solution concentration used was
500 mg L
−1
. As a result of this study, 95% of boron was removed. Borate ion was
adsorbed onto the magnesium oxide surface in aqueous solution. However, a metallic complex occurred between magnesium ions and borate ions in basic medium,
which was performed the precipitation reaction (Garcia-Soto and Camacho 2006).
Öztürk and Kavak (2008) used cerium oxide as the adsorbent for boron removal.
Statistical analysis was done to the experimental data by choosing the temperature,
solution pH, and particle type as the parameters. All the parameters have positive
effect on boron removal. However, temperature has the greatest effect on the removal
of boron. Langmuir isotherm model was fitted well the experimental data (Öztürk
and Kavak 2008).
Demetriou and Pashalidis (2012) studied boron removal from aqueous solution
using iron oxide. Experimental data showed that the adsorption mechanism depends
on the replacement of a water molecule by a boric acid molecule. Maximum adsorption capacity was achieved as 0.03 mol kg
−1
according to Langmuir isotherm model
(Demetriou and Pashalidis 2012).
Sub-micron calcium hydroxide particles were used for boron adsorption.
Modified sub-micron calcium hydroxide particles improved adsorption efficiency
compared with unmodified calcium hydroxide. The adsorption efficiency was
increased from 67.2% to 76.2% at the same experimental conditions (Tsai and
Lo 2015).
Prodromou (2004a, b) studied boron removal using amorphous aluminum
hydroxides. Boron adsorption was affected by the type of acids exist in the soil.
Boron adsorption increased according to the complexion reaction with the acids.
Maximum boron adsorption occurred around 76%, and Freundlich isotherm model
was the best isotherm model fitted the experimental data (Prodromou 2004a, b).
Freshly prepared magnesium hydroxide has the highest specific surface area.
Therefore, Prodromou (2004a, b) used fresh magnesium hydroxide to adsorb boron
from the aqueous solution. Complexation reaction occurs between magnesium
P. Demircivi