“PERFORMANCE TESTING OF A 380 ML/D RETROFITTED
MEMBRANE/UV OXIDATION WTP”
Brian Sahely, M.A.,Sc., P.Eng, AECOM Canada Ltd.
5600 Cancross Court, Suite A, Mississauga, ON L5R 3E9
[email protected] Phone: 905-712-6995
Jeff Hennings, P. Eng., M.Sc.Eng., Region of Peel, Brampton, ON
Sheldon Belbin, M.Env.Sci., Ontario Clean Water Agency, Mississauga, ON
Dean Baker, Ontario Clean Water Agency, Mississauga, ON
Brian Vistorino, P.Eng., Genivar, Markham, ON
Sophie Pease, P.Eng., GE Water & Process Technologies, Oakville, ON
Introduction
The Lorne Park Water Treatment Plant (WTP) is located in Mississauga, Ontario, Canada and is
owned by the Region of Peel. Between 2007 and August 2012, construction was completed for
the expansion of the plant to 500 ML/d, including the retrofit of 227 ML/d settling tanks (Figure
1) with 380 ML/d of membranes (Figure 2). Once the Lorne Park WTP was fully commissioned,
the membrane system had to be tested in accordance with the pre-selection document. This was
completed over a six month period with two of the sixteen membrane trains operating in
supervisory mode at maximum design capacity of 31.7 ML/d per train.
This article presents the results of the performance testing that was conducted and lessons
learned for future membrane performance testing.
Testing Results – General
Figure 1: 8 Settling Tanks w/ Plate Settlers (227 ML/d Conv. Plant)
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Figure 2: 16 Membrane Tanks w/ GE ZW1000 Modules
(380 ML/d Membrane Plant)
Performance Testing Results – General
Figures 3 to 6 shows the general performance testing results for cycles 2 and 3 passing the
following criteria:
·
Membrane flux @ 51 Lmh, i.e., 31.7 ML/d per train
·
Recovery @ 95% except when turbidity > 5 NTU
·
Log removal value (LRV) > 4.3-logs for first two years and then 4.0-logs afterwards
·
Permeate turbidity ≤ 0.1 NTU, 99% of time & ≤ 0.3 NTU, 100% of time
·
CIP frequency greater than 42 days cycle (or when TMP trigger at -83 kPa)
2
UF 42-FluxBeforeBP
UF 53-FluxBeforeBP
Target
54
Flux (Lmh)
53
52
51
50
49
48
06/07/2013 16/07/2013 26/07/2013 05/08/2013 15/08/2013 25/08/2013 04/09/2013 14/09/2013 24/09/2013
Figure 3: Membrane Flux
100
98
data not available
in InSIght
Recovery (%)
96
94
92
feed water
turbidity spike
90
88
7/6/2013
7/20/2013
8/3/2013
8/17/2013
8/31/2013
Figure 4: Recovery
3
9/14/2013
9/28/2013
UF 42-LRV
UF 53-LRV
Target
5.4
5.2
LRV (logs)
5.0
4.8
4.6
4.4
4.2
4.0
06/07/2013 16/07/2013 26/07/2013 05/08/2013 15/08/2013 25/08/2013 04/09/2013 14/09/2013 24/09/2013
Figure 5: LRV
UF 42-PermeateTurbidity
UF 53-PermeateTurbidity
Target
100
90
Permeate Turbidity (mNTU)
80
70
60
50
40
30
20
10
0
06/07/2013 16/07/2013 26/07/2013 05/08/2013 15/08/2013 25/08/2013 04/09/2013 14/09/2013 24/09/2013
Figure 6: Permeate Turbidity
4
UF 42-TMPBeforeBP
UF 53-TMPBeforeBP
UF Plant-PermeateTemperature1
Train 42 Hypo RC
Train 42 Acid RC
Train 42 Hypo RC
Train 42 Acid RC
Train 53 Hypo RC
Train 53 Acid RC
Train 53 Hypo RC
Train 53 Acid RC
Train 53 Hypo RC
Train 53 Acid RC
TMP (kPa) and Temperature (°C)
90
80
70
60
50
40
30
20
10
0
06/07/2013 16/07/2013 26/07/2013 05/08/2013 15/08/2013 25/08/2013 04/09/2013 14/09/2013 24/09/2013
Figure 7: TMP
Testing Results – Chemical Usage
Figures 8 to 10 show the target chemical concentrations and pH required for chemically
enhanced backwashes (CEBs) and/or clean-in-place (CIP) cycles and the chemical volumes
consumed versus those guaranteed for cycle 3. As shown, some of the chemical volumes
guaranteed were exceeded.
5
Guaranteed
160
145
140
Actual
135
120
100
80
60
38.4 35
40
20
9.2
14.6
0
Chlorine residual
(mg/L)
2.4 2.6
Sodium
Sodium
Sodium
hydroxide
bisulphite
hypochlorite
volume (L/clean) volume (L/clean) volume (L/clean)
Figure 8: Non-heated CEBs (~40 min duration, Every 2nd Days)
Guaranteed
450
400
350
300
250
200
150
100
50
0
Actual
385
320
96.2 94.5
23.2 22.6
Chlorine residual
(mg/L)
6
4.9
Sodium bisulphite Sodium hydroxide
Sodium
volume (L/clean) volume (L/clean)
hypochlorite
volume (L/clean)
Figure 9: Heated High pH CIPs (~5 Hours Duration, Every 42 Days)
6
Guaranteed
80
Actual
74.7 74.9
70
60
52.4
50
38.6
40
30
20
10
0
8.3 10.5
2.1 2.4
Cleaning pH
Citric acid volume Sulphuric acid Sodium hydroxide
(L/clean)
volume (L/clean) volume (L/clean)
Figure 10: Heated Low pH CIPs (~5 Hours Duration, Every 42 Days)
Testing Results - Power Usage
Figures 11 and 12 show the power distribution given various equipment. As shown, the
permeate pumps consume the most power at 96.6% of the total power usage. As a result, it
was agreed that only the permeate pump power will be monitored and evaluated for compliance
with the performance guarantee.
Two ION 7350 meters (Figure 13) were installed for the permeate pumps for the two membrane
trains being tested. Given 17,191 kWh/day permeate pump total plant guarantee, the
corresponding power expected from one permeate pump is 1,146 kWh/day at 2oC at 1,152
min/day. Given higher water temperatures and higher operating time, the corrected power
expected from one permeate pump at 14.4oC and 1,344 min/day is1,169 kWh/day.
Figure 14 shows the permeate pump speed during cycle 3 being 47% with the pump power
averaging 837 kW/day, which is lest than that required of 1,169 kWh/day.
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1.30%
0.30%
0.30%
1.40%
0.10%
Backpulse
Pumps
Cleaning
Pumps
Blowers
Compressors
Recirculation
Pumps
96.60%
Permeate
Pumps
Power Distribution (%)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
55
249
10
Compressor
s
Recirculatio
n Pumps
55
Blowers
230
Cleaning
Pumps
17,191
Backpulse
Pumps
20,000
18,000
16,000
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
Permeate
Pumps
Power Consumption (Kwh/day)
Figure 11: Membrane Equipment Power Distribution (Percentage)
Figure 12: Membrane Equipment Power Distribution (kWh/day)
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Figure 13: ION 7350 Meters Installed on Two Permeate Pumps
700
30%
600
20%
500
10%
400
0%
24-Sep-13
40%
17-Sep-13
800
10-Sep-13
50%
3-Sep-13
900
27-Aug-13
60%
Figure 14: Permeate Pump Power and VFD Speed for Cycle 3
9
Pump Speed (%)
Equivalent Average Pump Speed %
1,000
20-Aug-13
Pump Power Usage (kW.h)
kW.h Usage
Liquidated Damages/Penalties
The pre-selection document specified liquidated damages/penalties for various performance
parameters. These are shown in Table 1 with the performance achieved in this peformance
testing for cycle 3 shown along with the net liquidated damages listed. As shown, a savings of
approximately $4.61MM can be recognized from cycle 3 performance testing.
Table 1: Liquidated Damages (Net Savings of $4.6MM)
Performance
Parameter
Recovery (%)
CIP Interval
(# cleans/year)
Power use for
1 Process
Pump
(kWh/day)
Production
Capacity for 1
Process Pump
(ML/d)
Chemical
Usage
Total Net
Liquidated
Damages
Performance Unit for Liquidated Performance
Achieved
Required
Liquidated Damages
per Unit
Damages
0.5
$400,000
$95.75
95
1
$78,000
6
9
Net Liquidated
Damages
-$600,000
-$234,000
1,169
1
$11,388
837
-$3,780,816
31.67
0.1
$80,000
31.67
$0
Varies
Varies
Varies
Varies
$229,919
-
-
-
-
-$4,614,816
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Lessons Learned
1. Lengthy performance testing is beneficial as operator training and “new findings”, e.g.,
incorrect recovery calculations, membrane tank temperature maintenance, backwash
trigger logic, CIP trigger setpoints, analyzer concerns, etc.
2. Develop a performance testing protocol during pre-selection that matches exactly how it
would be performed given any limitations such as flow. Request guarantees specific to
performance testing, even if different from long-term guarantees. Request specific
programming for the specific protocol.
3. Install ION meters on membrane equipment to allow for tracking of power short-term
and long-term. Separate building loads from ION meters.
4. Specify TMP guarantees instead of power guarantees given difficulty in monitoring
power and correction factors that are required.
5. Targeting a pH or chlorine concentration can be difficult. If possible, on-line analyzers to
allow for chemical dosing compound loops to achieve targets.
6. Monitor and maintain sufficient flow to on-line analyzers for them to work properly.
7. Avoid long sample lines to on-line analyzers to prevent incorrect readings, especially
temperature, given the impacts of ambient temperature.
8. Performance testing with penalties can inhibit optimization of the system given that
suppliers primary goal is to remain within guarantees at all times.
9. Continue testing and reporting for 1st year across all seasons especially at worst water
quality, e.g., temperature.
10. Conduct plant wide FAT in advance of commissioning as done for the Lorne Park WTP.
This made performance testing a “piece of cake” when it came to controls!!!
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