58
3.1 Materials
The details of the chemicals used in the present research are presented in Table 3.1. All the purchased chemicals were used without further purification.
Table 3. 1 Chemicals used in the present work.
Chemicals Supplier
MW g∙mol
-1
T
m
°C T
b
°C ρT = 25 °C
g∙cm
-3
Methyldiethanolamine MDEA Merck
119.16 -55
247.30 1.04
Hydrogen Peroxide H
2
O
2
30 Merck
34.01 -0.43
150.20 1.11
Potassium Permanganate KMnO
4
Merck 158.03
240 -
2.70 Disodium Hydrogen Phosphate
Na
2
HPO
4
Merck 141.96
250 -
1.7 Calcium Hydroxide CaOH
2
Merck 74.09
580 -
2.21 Sulfuric Acid H
2
SO
4
Merck 98.08
10 337
1.84 Sodium Hydroxide NaOH
R M Chemical
39.99 318
1338 2.13
3.1.1 MDEA Contaminated WaterEffluents
For the present experiments, two kinds of MDEA contaminated wastewater were used i.e. simulated wastewater and actual wastewater from gas processing unit. Synthetic
wastewater was prepared by dissolving a required quantity of MDEA into distilled water. For example, for the preparation of a 2000 ppm of MDEA solution, 1.92 ml of
MDEA was dissolved into 1 liter of distilled water. This concentration is approximately equals to 1020 ppm of total organic carbon TOC or aprroximately
equals to 0.085 M organic carbon C. Figure 3.2 and Figure 3.3 show the correlation between the MDEA concentration with the total organic carbon TOC value and the
MDEA concentration with the organic carbon C concentration, respectively.
59
Figure 3.2 Correlation of MDEA concentrations with total organic carbon TOC.
Y = 0.5302X; R
2
= 0.9977
Figure 3. 3 Correlation of MDEA concentrations with organic carbon.
Y = 5 x 10
-4
X; R
2
= 0.9977
60 Actual wastewater was obtained from Petronas Penapisan Melaka Sendirian
Berhad PPMSB, Malaysia. The concentrations of various compounds present in the obtained effluent solution are shown in Table 3.2. Based on the preliminary studies,
conducting the experiment at high concentration of contaminat was a time consuming, therefore the PPMSB effluent which has a very high MDEA concentration was further
diluted before subjecting to the degradation process using UVH
2
O
2
oxidation process.
Table 3. 2 The properties of PPMSB effluent.
Measures Remarks
MDEA 340000 ppm
TOC 175000 ppm
COD 500000 ppm
S
2-
500 ppm NH
4 +
4156 ppm Acetic acid
1566 ppm Oxalic acid
13847 ppm Oil and grease
250 ppm pH
10
The real wastewater obtained from gas processing unit contain H
2
S toxic gas apart from oil and grease, which will certainly affect the demineralization of MDEA,
and hence these contaminants have to be removed before further treatment. Initially, the oil and grease were separated by allowing the effluent to settle in
separating funnel for overnight. The oil and grease free solution which settled at the upper layer were separated. The removal of H
2
S was conducted using the following oxidation process Equation 3.1:
Ol H
s S
O H
S H
2 2
2 2
3.1
For the oxidation purpose 2 ml of 30 H
2
O
2
was added to every 100 ml of effluents, and the obtained yellow precipitate sulphur was then removed by filtration.
61
3.1.2 Reagents Used
Kategori