use in oilsorption processes as a sorbent. Fly ash has hydrophilic surface, which must
be improved for use as sorbent.
Banerjee et al. (2006) modified fly ash by hexadecyltrimethylammonium as a
cationic surfactant. Then, they investigated the ability of modified fly ash for the
uptake of crude oil (Arabian light) and weathered crude oil. Some properties of crude
oil and fly ash are provided in Table 12.12.
They treated the hydrophobic fly ash by hexadecyltrimethylammonium cation,
[(CH 3 ) 3 NC 16 H 33 ]
+
, to make organophilic fly ash. Moreover, the oil uptake of
modified fly ash was compared with wood shavings. The modification of fly ash
was performed with the following reaction:
Si‐OH þ Br CH 3
ð
Þ 3 NC 16 H 33
Â
à ! Si‐O‐N CH 3
ð
Þ 3 C 16 H 33
ð
Þ
Â
à þ HBr
ð12:1Þ
where the hydroxyl group of fly ash reacts with cation [(CH 3 ) 3 N(C 16 H 33 )]
+
.
The scanning electron microscope images of fly ash and modified fly ash revealed
that the modification with hexadecyltrimethylammonium cation changed the surface
roughness of fly ash and the surface of modified fly ash was smoother than that of fly
ash. For different ratios of oil/water, the oilsorption results of fly ash and modified fly
ash (Fig. 12.36) indicated that the oil uptake of fly ash was lower than that of
modified fly ash due to its SiO polar group that reacts with water and nonpolar
organic material cannot compete with it.
Table 12.12 Some properties of crude oil and fly ash characteristics (Banerjee et al. 2006)
Property/characteristic
Value
Mean particle size of fly ash
47.90 μm
Surface area of fly ash
3.12 m
2
/g
Viscosity of crude oil
42.46 cp
Specific gravity of crude oil
0.894 g/cm
3
Fig. 12.36 The oilsorption capacity of fly ash (FA) and modified fly ash by
hexadecyltrimethylammonium (HDTMA-FA) for different ratios of oil/water. (Modified after
Banerjee et al. 2006)
446
M. Fatehi et al.
be improved for use as sorbent.
Banerjee et al. (2006) modified fly ash by hexadecyltrimethylammonium as a
cationic surfactant. Then, they investigated the ability of modified fly ash for the
uptake of crude oil (Arabian light) and weathered crude oil. Some properties of crude
oil and fly ash are provided in Table 12.12.
They treated the hydrophobic fly ash by hexadecyltrimethylammonium cation,
[(CH 3 ) 3 NC 16 H 33 ]
+
, to make organophilic fly ash. Moreover, the oil uptake of
modified fly ash was compared with wood shavings. The modification of fly ash
was performed with the following reaction:
Si‐OH þ Br CH 3
ð
Þ 3 NC 16 H 33
Â
à ! Si‐O‐N CH 3
ð
Þ 3 C 16 H 33
ð
Þ
Â
à þ HBr
ð12:1Þ
where the hydroxyl group of fly ash reacts with cation [(CH 3 ) 3 N(C 16 H 33 )]
+
.
The scanning electron microscope images of fly ash and modified fly ash revealed
that the modification with hexadecyltrimethylammonium cation changed the surface
roughness of fly ash and the surface of modified fly ash was smoother than that of fly
ash. For different ratios of oil/water, the oilsorption results of fly ash and modified fly
ash (Fig. 12.36) indicated that the oil uptake of fly ash was lower than that of
modified fly ash due to its SiO polar group that reacts with water and nonpolar
organic material cannot compete with it.
Table 12.12 Some properties of crude oil and fly ash characteristics (Banerjee et al. 2006)
Property/characteristic
Value
Mean particle size of fly ash
47.90 μm
Surface area of fly ash
3.12 m
2
/g
Viscosity of crude oil
42.46 cp
Specific gravity of crude oil
0.894 g/cm
3
Fig. 12.36 The oilsorption capacity of fly ash (FA) and modified fly ash by
hexadecyltrimethylammonium (HDTMA-FA) for different ratios of oil/water. (Modified after
Banerjee et al. 2006)
446
M. Fatehi et al.