PART A
1. (a)
Table 1: Acetic Acid limiting data
Operation
Cin
(%)
Cout
(%)
∆C
(%)
SK1-SR1
SK2-SR2
SK3-SR3
SK4-SR4
SK5
85
55
15
90
97.5
92
88.5
76.5
98.5
0
7
33.5
61.5
8.5
-97.5
Inlet
Flow, SK
(t/h)
66.34
18.82
23.33
15.51
104.57
Outlet
Flow, SR
(t/h)
60.96
18.75
35.63
150.28
0
Limiting
Flowrate, F
(t/h)
60.96
18.75
23.33
15.51
0
Loss/Gain
(t/h)
-5.38
-0.07
12.3
134.77
-104.57
Mass
load
(kg/h)
85
4267.2
55
6281.25
76.5 14347.95
98.5 1318.35
97.5
0
Ci
(%)
(b)
Table 2: Acetic Acid limiting flowrate table
Ci (%)
15
55
76.5
85
88.5
90
92
97.5
98.5
Op 1
60.96
60.96
60.96
Op 2
18.75
18.75
18.75
Op 3
Op 4
Sum Fi (t/h)
∆Ci
∆M (kg/h)
15.51
15.51
15.51
23.33
42.08
18.75
79.71
60.96
76.47
15.51
15.51
40
21.5
8.5
3.5
1.5
2
5.5
1
9332
9047.2
1593.75
2789.85
914.4
1529.4
853.05
155.1
23.33
23.33
Mi
(kg/h)
0
9332
18379.2
19972.95
22762.8
23677.2
25206.6
26059.65
26214.75
Table 3: Acetic Acid source table
Ci (%)
12.5
15
55
76.5
85
88.5
90
92
97.5
98.5
AA
Flowrate
(t/h)
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
29.81
Op 1
-5.38
-5.38
-5.38
-5.38
-5.38
Op 2
-0.07
-0.07
-0.07
-0.07
-0.07
-0.07
-0.07
Op 3
12.3
12.3
12.3
12.3
12.3
12.3
Op 5
-104.57
Sum Fi
(t/h)
∆Ci
∆Mi
(kg/h)
Mi (kg/h)
29.81
29.81
29.81
29.74
42.04
36.66
36.66
36.66
36.66
-67.91
0
2.5
40
21.5
8.5
3.5
1.5
2
5.5
1
0.00
745.36
11925.84
6395.09
3573.79
1283.26
549.97
733.29
2016.55
-679.05
0.00
745.36
12671.20
19066.29
22640.08
23923.34
24473.31
25206.60
27223.15
26544.10
Limiting composite curve
100
90
PINCH
80
Concentration (%)
70
- 0.07 t/h
+ 12.3 t/h
60
- 5.38 t/h
- 0.07 t/h
+ 12.3 t/h
50
- 0.07 t/h
40
30
20
10
0
0
5000
10000
15000
20000
25000
Mass load (kg/h)
AA Limi ting Flowrate
AA S ource
Figure 1: Acetic acid composite curve
The pinch is at 92%. The minimum fresh acetic acid flowrate was determined to be 29.81
using the goal seek function on Excel to match the mass load at the pinch point for the
curves of the limiting flowrate of acetic acid as well as the acetic acid source. Also by mass
balance below the pinch:
25.2066 𝑡/ℎ = 𝐹𝐴𝐴(0.55 − 0.125) + (𝐹𝐴𝐴 − 0.07)(0.765 − 0.55)
+ (𝐹𝐴𝐴 + 12.3 − 0.07)(0.85 − 0.765) + (𝐹𝐴𝐴 − 5.38 − 0.07 + 12.3)(0.92
− 0.85)
𝐹𝐴𝐴 = 29.81 𝑡/ℎ
The minimum discharge flowrate is then:
29.81 − 5.38 − 0.07 + 12.3 + 134.77 − 104.57 = 66.9 𝑡/ℎ
30000
2. Network Diagram
Figure 2: AA recovery network based on limiting AA flowrate of 29.8 t/h and minimum discharge flowrate of 66.9 t/h
3. Two separation methods:
a. Membrane separation
b. Liquid-liquid extraction
PART B
4.
Table 4: Wastewater streams extracted from Q2
W (Plant)
W1 (PHA)
W2 (AN)
W3 (VAM)
W4 (WWTP)
Flowrate (t/h)
5.1
61.8
Impurity (%)
92
88.5
76.5
98.5
The density of the waste streams is assumed to be equal to that of water (1000 kg/m 3).
Therefore, the flowrate can be converted to L/h by:
𝐿
𝑡
1000 𝑘𝑔
1
1000 𝐿
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( ) = 𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( ) ×
×
×
3
ℎ
ℎ
1𝑡
1000 𝑘𝑔/𝑚
1 𝑚3
The mass loading for each waste stream can be calculated by:
𝐿
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( ) × 𝐼𝑚𝑝𝑢𝑟𝑖𝑡𝑦(%)
ℎ
𝑀𝑎𝑠𝑠 𝑙𝑜𝑎𝑑𝑖𝑛𝑔 =
100
The mass of ethanol in the waste stream:
6.7𝑔
𝐿
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( ) × 𝐿 𝑐𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 × 1𝑘𝑔
𝑘𝑔
ℎ
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 ( ) =
ℎ
1000 𝑔
Moles of ethanol:
𝑘𝑔
𝑘𝑔
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 ( )
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 ( )
𝑘𝑚𝑜𝑙
ℎ
ℎ
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 (
)=
=
𝑘𝑔
𝑘𝑔
ℎ
𝑀𝑜𝑙𝑎𝑟 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 (
)
46
𝑘𝑚𝑜𝑙
𝑘𝑚𝑜𝑙
Reaction of ethanol with oxygen: C2H5OH + 3O2  2CO2 + 3H2O
Moles of oxygen:
𝑘𝑚𝑜𝑙
𝑘𝑚𝑜𝑙
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑜𝑥𝑦𝑔𝑒𝑛 (
) = 3 × 𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑒𝑡ℎ𝑎𝑛𝑜𝑙 (
)
ℎ
ℎ
The theoretical oxygen or COD of ethanol:
𝑘𝑚𝑜𝑙
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑜𝑥𝑦𝑔𝑒𝑛 (
) × 32 𝑘𝑔/𝑘𝑚𝑜𝑙 1000000 𝑚𝑔
ℎ
𝐶𝑂𝐷𝑒𝑡ℎ𝑎𝑛𝑜𝑙 (𝑝𝑝𝑚) =
×
𝐿
1 𝑘𝑔
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( )
ℎ
The following table summarizes the COD of ethanol in the two waste streams.
Table 5: Ethanol COD in waste streams
W
(plant)
W1
(PHA)
W2 (AN)
W3
(VAM)
W4
(WWTP)
Flowrate
(L/h)
Mass
loading
(L/h)
Mass of
ethanol
(kg/h)
Ethanol
moles
(kmol/h)
Moles of
oxygen
(kmol/h)
COD
ethanol
(kg/L)
COD
ethanol
(ppm)
5100
4692
31.44
0.68
2.05
0.01
12864.00
-
-
-
-
-
-
-
-
-
-
-
-
-
-
61800
60873
407.85
8.87
26.60
0.01
13772.87
For the COD of butyric acid, and propionic acid, the COD of acetic acid is first calculated as
follows:
𝑡
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( ) × (100 − 𝐼𝑚𝑝𝑢𝑟𝑖𝑡𝑦(%)) 1000𝑘𝑔
𝑘𝑔
ℎ
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 ( ) =
×
ℎ
100
1𝑡
Moles of acetic acid:
𝑘𝑔
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 ( )
ℎ
𝑘𝑔
𝑀𝑜𝑙𝑎𝑟 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 (
)
𝑘𝑚𝑜𝑙
𝑘𝑔
𝑀𝑎𝑠𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 ( )
ℎ
=
𝑘𝑔
60
𝑘𝑚𝑜𝑙
𝑘𝑚𝑜𝑙
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 (
)=
ℎ
Reaction of acetic acid with oxygen: CH3COOH + 2O2  2CO2 + 2H2O
𝑘𝑚𝑜𝑙
𝑘𝑚𝑜𝑙
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑜𝑥𝑦𝑔𝑒𝑛 (
) = 2 × 𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 (
)
ℎ
ℎ
The theoretical oxygen or COD of acetic acid:
𝑘𝑚𝑜𝑙
𝑀𝑜𝑙𝑒𝑠 𝑜𝑓 𝑜𝑥𝑦𝑔𝑒𝑛 (
) × 32 𝑘𝑔/𝑘𝑚𝑜𝑙 1000000 𝑚𝑔
ℎ
𝐶𝑂𝐷𝑎𝑐𝑒𝑡𝑖𝑐 𝑎𝑐𝑖𝑑 (𝑚𝑔/𝐿) =
×
𝐿
1 𝑘𝑔
𝐹𝑙𝑜𝑤𝑟𝑎𝑡𝑒 ( )
ℎ
The theoretical oxygen or COD of butyric acid:
𝑚𝑔
400 𝑚𝑔 𝐶𝑂𝐷𝐵𝐴 /𝐿
𝐶𝑂𝐷𝐵𝐴 = 𝐶𝑂𝐷𝐴𝐴 × 𝑟𝑎𝑡𝑖𝑜 = 𝐶𝑂𝐷𝐴𝐴 ( ) ×
𝐿
3145 𝑚𝑔 𝐶𝑂𝐷𝐴𝐴 /𝐿
The theoretical oxygen or COD of propionic acid
𝑚𝑔
400 𝑚𝑔 𝐶𝑂𝐷𝑃𝐴 /𝐿
𝐶𝑂𝐷𝑃𝐴 = 𝐶𝑂𝐷𝐴𝐴 × 𝑟𝑎𝑡𝑖𝑜 = 𝐶𝑂𝐷𝐴𝐴 ( ) ×
𝐿
3145 𝑚𝑔 𝐶𝑂𝐷𝐴𝐴 /𝐿
Above calculations are summarized into the following table.
Table 6: Calculated CODs for BA and PA
W
(plant)
Flowrate
(L/h)
Acetic
acid
(kg/h)
Acetic Moles of Oxygen
Acid
oxygen
(kg/t)
(kmol/h) (kmol/h)
Acetic
COD BA
COD PA
Acid
(mg/L)
(mg/L)
COD
(mg/L)
85333.33 10853.21 107555.27
W1
(PHA)
W2 (AN)
W3
(VAM)
W4
(WWTP)
5100
408.00
6.80
13.60
85.33
-
-
-
-
-
-
-
-
61800
927.00
15.45
30.90
16.00
16000.00
2034.98
20166.61
The total COD and subsequently BOD5 are computed and tabulated as below:
Table 7: Wastewater streams data from AA network
W (plant)
Flowrate (t/h)
W1 (PHA)
W2 (AN)
W3 (VAM)
W4 (WWTP)
5.10
61.80
Impurity
content (%)
92.00
98.50
Total COD
(ppm)
131272.48
35974.46
Total BOD
(ppm)
39381.74
10792.34
5. (a)
Table 8: Summary of all waste streams going into the centralised filtration system
Plant
Flowrate (t/h)
W1 (PHA)
W4 (WWTP)
W5 (PHA)
W6 (AN)
W7 (VAM)
W8 (Centralised)
5.10
61.80
30.65
56.54
33.92
196.70
Impurity
content (%)
92.00
98.50
79.45
93.16
68.65
45.98
Total COD
(ppm)
131272.48
35974.46
221539.51
259772.48
191428.21
128205.13
Total BOD
(ppm)
39381.74
10792.34
66461.85
77931.74
57428.46
38461.54
The impurity content of stream W5, W6, W7, W8 is calculated by the addition of the values
of the total dissolved solids (TDS) and the total suspended solids (TSS).
PHA Plant
Table 9: Load table for constructing PHA plant effluent composite curve
BOD (ppm)
500.00
39381.74
66461.85
FW1
(t/h)
5.10
FW5
(t/h)
Sum F
30.65
30.65
∆BOD (ppm)
35.75
30.65
38881.74
27080.11
M (t/h)
Cum M (t/h)
1.39
0.83
0.00
1.39
2.22
PHA plant effluent composite curve (W1 & W5)
70000.00
BOD (ppm)
60000.00
50000.00
40000.00
30000.00
Pinch
(1.39, 39381.74)
20000.00
10000.00
0.00
-0.50
0.00
0.50
1.00
1.50
2.00
2.50
Mass (t/h)
Effluent curve
Mini mum treatment flowrate
Figure 3: PHA plant effluent composite curve
With a removal ratio (RR) of 0.998, the total mass load is calculated:
𝑡
2.22
∆𝑀𝑇
𝑡
ℎ
𝑀𝑇 =
=
= 2.22
0.998 0.998
ℎ
The x-intercept of the minimum treatment flowrate:
∆𝑀𝑇 − 𝑀𝑇 = −0.004449
The treatment line will pass through (-0.004449, 0) until the pinch point at (1.39, 39381.74)
Hence, the flowrate is:
𝑡
(1.39 − (−0.004449))
𝑚
𝑡
ℎ
𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 =
=
= 35.41
∆𝐵𝑂𝐷
39381.74 𝑝𝑝𝑚 − 0
ℎ
The filtration system for the polyhydroxialkanoates (PHA) plant is shown below:
Figure 4: PHA plant wastewater filtration design
The cost of the PHA plant wastewater treatment system is calculated below:
𝑡 $0.8
𝑡 $0.5 $18.3
𝐶𝑜𝑠𝑡 = 2 ∗
+ (35.75 − 2) ∗
=
ℎ
𝑡
ℎ
𝑡
ℎ
WWT Plant
Table 10: Load table for constructing WWTP plant effluent composite curve
BOD (ppm)
FW4
(t/h)
FW8
(t/h)
Sum F
∆BOD (ppm)
M (t/h)
Cum M (t/h)
500.00
10792.34
38461.54
61.80
196.70
196.70
258.50
196.70
10292.34
27669.20
2.66
5.44
0.00
2.66
8.10
WWTP plant effluent composite curve (W4 &W8)
BOD (ppm)
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
-1
0
Pinch
(2.66, 10792.34)
1
2
3
4
5
6
7
Mass (t/h)
Effluent curve
Mini mum treatment flowrate
Figure 5: WWTP effluent composite curve
8
9
The total mass load is calculated as follows:
𝑡
8.10
∆𝑀𝑇
𝑡
ℎ
𝑀𝑇 =
=
= 8.12
0.998 0.998
ℎ
The x-intercept of the minimum treatment flowrate:
∆𝑀𝑇 − 𝑀𝑇 = −0.016239
The treatment line will pass through (-0.016239, 0) until the pinch point at (2.66, 10792.34)
Hence, the flowrate is:
𝑡
(2.66 − (−0.016239))
𝑚
𝑡
ℎ
𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 =
=
= 248.03
∆𝐵𝑂𝐷
10792.34 𝑝𝑝𝑚 − 0
ℎ
The filtration system for the wastewater treatment (WWT) plant is shown below:
Figure 6: WWTP wastewater filtration design
The cost of the wastewater treatment system is as follows:
𝑡 $0.8
𝑡 $0.5 $124.6
𝐶𝑜𝑠𝑡 = 2 ∗
+ (258.5 − 2) ∗
=
ℎ
𝑡
ℎ
𝑡
ℎ
AN Plant
Table 11: Load table for constructing AN plant effluent curve
BOD (ppm)
500.00
77931.74
FW6 (t/h)
∆BOD (ppm)
56.54
77431.74
M (t/h)
0.00
4.38
AN plant effluent curve (W6)
BOD (ppm)
90000.00
80000.00
70000.00
60000.00
50000.00
40000.00
30000.00
20000.00
10000.00
0.00
-1.00
0.00
1.00
2.00
3.00
4.00
5.00
Mass (t/h)
Effluent curve
Mini mum treatment flowrate
Figure 7: AN plant effluent curve
Similarly, total mass load is calculated as follows:
𝑡
4.38
∆𝑀𝑇
𝑡
ℎ
𝑀𝑇 =
=
= 4.39
0.998 0.998
ℎ
The x-intercept of the minimum treatment flowrate:
∆𝑀𝑇 − 𝑀𝑇 = −0.009
The treatment line will pass through (-0.009, 0) and the only one point on the curve at (4.38,
77931.74) Hence, the flowrate is:
𝑡
(4.38 − (−0.009))
𝑚
𝑡
ℎ
𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 =
=
= 56.29
∆𝐵𝑂𝐷
77931.74 𝑝𝑝𝑚 − 0
ℎ
The filtration system for the Acetic Anhydrate (AN) plant is shown below:
Figure 8: AN plant wastewater filtration design
The cost associated with the AN plant wastewater treatment system is shown below:
𝑡 $0.8
𝑡 $0.5 $28.7
𝐶𝑜𝑠𝑡 = 2 ∗
+ (56.54 − 2) ∗
=
ℎ
𝑡
ℎ
𝑡
ℎ
VAM Plant
Table 12: Load table for constructing VAM plant effluent curve
BOD
(ppm)
500.00
57428.46
FW7
(t/h)
∆BOD
(ppm)
33.92
10292.34
M (t/h)
0.00
0.35
VAM plant effluent curve (W7)
70000.00
60000.00
BOD (ppm)
50000.00
40000.00
30000.00
20000.00
10000.00
0.00
-0.50
0.00
0.50
1.00
1.50
2.00
2.50
Mass (t/h)
Effluent cur ve
Limiting treatment flowrate
Figure 9: VAM plant effluent curve
Total mass load:
𝑡
1.93
∆𝑀𝑇
ℎ = 1.93 𝑡
𝑀𝑇 =
=
0.998 0.998
ℎ
The x-intercept of the minimum treatment flowrate:
∆𝑀𝑇 − 𝑀𝑇 = −0.004
The treatment line will pass through (-0.004, 0) and the only one point on the curve which is
at (1.93, 57428.46) Hence, the flowrate is:
𝑡
(1.93 − (−0.004))
𝑚
𝑡
ℎ
𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 =
=
= 33.69
∆𝐵𝑂𝐷
57428.46 𝑝𝑝𝑚 − 0
ℎ
The filtration system for the vinyl acetate monomer (VAM) plant is shown in Figure 10.
Figure 10: VAM plant wastewater filtration design
The cost for treating the waste at the VAM plant is then calculated as follows:
𝑡 $0.8
𝑡 $0.5 $17.4
𝐶𝑜𝑠𝑡 = 2 ∗
+ (33.92 − 2) ∗
=
ℎ
𝑡
ℎ
𝑡
ℎ
The following table summarizes the minimum treatment flowrates and the cost associated
with treating the wastewater at all four plants:
Table 13: Individual wastewater treatment system summary
Plant
PHA (W1 & W5)
WWT (W4 & W8)
AN (W6)
VAM (W7)
Minimum treatment flowrate (t/h)
35.40907942
248.0285598
56.2898263
33.69206016
Total cost
Cost ($/h)
18.30
124.61
28.74
17.45
189.11
(b) The discharge limit CDBOD is given by 500 ppm with a removal ratio of 0.998.
Table 14: Load table for constructing the effluent curve of the centralised filtration system
BOD
(ppm)
500.00
10792.34
38461.54
39381.74
57428.46
66461.85
77931.74
Cum M
(kg/h)
0.00
5.10 61.80 30.65 56.54 33.92 196.70 384.71 10292.34 3959.57 3959.57
5.10
30.65 56.54 33.92 196.70 322.91 27669.20 8934.66 12894.23
5.10
30.65 56.54 33.92
126.21 920.20
116.14 13010.37
30.65 56.54 33.92
121.11 18046.72 2185.64 15196.00
30.65 56.54
87.19 9033.39 787.62 15983.63
56.54
56.54 11469.89 648.51 16632.13
FW1
FW4
FW5
FW6
FW7
FW8
Sum F
(t/h)
∆BOD
(ppm)
∆M
(kg/h)
∆𝑀𝑇
= 𝑅𝑅
𝑀𝑇
𝑘𝑔
16632.13
−0
∆𝑀𝑇
ℎ𝑟
𝑀𝑇 =
=
= 16665.46
𝑅𝑅
0.998
Hence, 𝑀𝑇 − ∆𝑀𝑇 = 33.33
Therefore, the minimum treatment flowrate line will start from (-33.33, 0) to the pinch
point.
Pinch
(3959.57, 10792.34)
Figure 11: The effluent composite curve for the centralised filtration system
The pinch concentration is at 10792.34 ppm.
The treatment flowrate is:
𝑇𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒 =
𝑚
(3959.57 − (−33.33))𝑘𝑔/ℎ𝑟 × 1000
=
= 369.98 𝑡/ℎ𝑟
∆𝐵𝑂𝐷
10792.34 𝑝𝑝𝑚 − 0
The concentrations of W1, W5, W6, W7, W8 streams are above the pinch concentration and
thus, these streams would be all sent to the centralised filtration system. Stream W4 which
is coming in at the pinch concentration would partially be treated by the system and
partially bypassed. The resulting design for the centralised filtration system is shown in
Figure 12.
Figure 12: Design of the centralised filtration system
For a flow rate of 369.7 t/h going into the centralised filtration system, the first two tonnes
would cost $1.6/h.
For the subsequent mass load, the cost would be $183.99/h.
Therefore, the total cost for the centralised filtration system to treat the wastestream is
$185.59 $/h.
(c) The overall treatment cost of the centralised filtration system is slightly lower at $185/h
compared to the total cost of individual filtration systems at $189.11/h. Therefore, in this
case, the lower cost option which is the centralised filtration system is recommended to
treat the waste streams. However, there are foreseen issues associated with a centralized
filtration system which include the possibility of having to combine different technologies
for the waste streams as different waste streams might require different technologies or
filtration methods for an efficient treatment. Since different technologies would have
different operating costs, it is recommended that the technology requirement for these
different streams be further investigated so that the actual cost for these treatment plants
can be effectively computed based on the method used.