Chemistry Reference
In-Depth Information
A: Reported method after
microwave-assisted dissolution
B:NAA without dissolution
A: Reported method after
microwave-assisted dissolution
B:NAA without dissolution
14
90
12
80
70
10
60
8
50
6
40
30
4
20
2
10
0
0
A
B
A
B
A
B
A
B
A
B
Co
Cs
U
Cr
Sb
Elements
Elements
A: Reported method after
microwave-assisted dissolution
B:NAA without dissolution
A: Reported method after
microwave-assisted dissolution
B:NAA without dissolution
2.5
5000
2.0
4000
1.5
3000
1.0
2000
0.5
1000
0.0
0
A
B
A
B
Fe
Zn
Element
Element
Figure 3.3
Intermethod comparison for concentration of selected elements.
Green laboratory proposal
[10]
Superheated liquid-liquid extraction was carried out using an extractor [9],
shown in Figure 3.4 consisted of the following components: (1) an electrically heated oven (HP 5720A,
Hewlett-Packard) for keeping the extraction coil at the desired temperature (the coil is a stainless steel tube
of 6 m × 0.4 mm i.d.); (2) a high pressure pump (Shimadzu) for propelling the extractant; (3) a dosifier piston
pump (Euromotori) for propelling the oil; (4) a T-junction as confluence point for allowing both phases to be
merged; (5) a cooling system (consisting of a coil located in a water bath at 25°C) for cooling the effluent
from the oven. All connections were made with stainless steel tubes/coil (i.d. 6 mm).
For extraction of copper, iron, nickel, vanadium, zinc from industrial oils, acidified water containing 20
%
(
v/v
) HNO
3
+
1 M KCl at a temperature of 175°C has been found to be effective. The contaminated oil and
