PERFORMANCE TESTING OF A 380 ML/D RETROFITTED MEMBRANE/UV OXIDATION WTP. Introduction

Transcription

1 PERFORMANCE TESTING OF A 38 ML/D RETROFITTED MEMBRANE/UV OXIDATION WTP Brian Sahely, M.A.,Sc., P.Eng, AECOM Canada Ltd. 56 Cancross Court, Suite A, Mississauga, ON L5R 3E9 Brian.sahely@aecom.com Phone: 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 27 and August 212, construction was completed for the expansion of the plant to 5 ML/d, including the retrofit of 227 ML/d settling tanks (Figure 1) with 38 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) 1

2 Figure 2: 16 Membrane Tanks w/ GE ZW1 Modules (38 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 51 Lmh, i.e., 31.7 ML/d per train 95% except when turbidity > 5 NTU Log removal value (LRV) > 4.3-logs for first two years and then 4.-logs afterwards Permeate turbidity.1 NTU, 99% of time &.3 NTU, 1% of time CIP frequency greater than 42 days cycle (or when TMP trigger at -83 kpa) 2

3 54 UF 42-FluxBeforeBP UF 53-FluxBeforeBP Target 53 Flux (Lmh) /7/213 16/7/213 26/7/213 5/8/213 15/8/213 25/8/213 4/9/213 14/9/213 24/9/213 1 Figure 3: Membrane Flux data not available in InSIght Recovery (%) feed water turbidity spike /6/213 7/2/213 8/3/213 8/17/213 8/31/213 9/14/213 9/28/213 Figure 4: Recovery 3

4 UF 42-LRV UF 53-LRV Target LRV (logs) /7/213 16/7/213 26/7/213 5/8/213 15/8/213 25/8/213 4/9/213 14/9/213 24/9/213 Figure 5: LRV 1 UF 42-PermeateTurbidity UF 53-PermeateTurbidity Target 9 Permeate Turbidity (mntu) /7/213 16/7/213 26/7/213 5/8/213 15/8/213 25/8/213 4/9/213 14/9/213 24/9/213 Figure 6: Permeate Turbidity 4

5 9 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) /7/213 16/7/213 26/7/213 5/8/213 15/8/213 25/8/213 4/9/213 14/9/213 24/9/213 Figure 7: TMP Testing Results Chemical Usage Figures 8 to 1 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

6 Guaranteed Actual Chlorine residual (mg/l) Sodium hypochlorite Sodium bisulphite Sodium hydroxide Figure 8: Non-heated CEBs (~4 min duration, Every 2 nd Days) Guaranteed Actual Chlorine residual (mg/l) Sodium hypochlorite Sodium bisulphite Sodium hydroxide Figure 9: Heated High ph CIPs (~5 Hours Duration, Every 42 Days) 6

7 8 7 Guaranteed Actual Cleaning ph Citric acid volume (L/clean) Sulphuric acid Sodium hydroxide Figure 1: 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 735 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 2 o C at 1,152 min/day. Given higher water temperatures and higher operating time, the corrected power expected from one permeate pump at 14.4 o C 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. 7

8 1% 96.6% 9% Power Distribution (%) 8% 7% 6% 5% 4% 3% 2% 1% % 1.3%.3%.3% 1.4%.1% Permeate Backpulse Cleaning Blowers Compressors Recirculation Figure 11: Membrane Equipment Power Distribution (Percentage) Power Consumption (Kwh/day) 2, 18, 16, 14, 12, 1, 8, 6, 4, 2, 17, Permeate Backpulse Cleaning Blowers Compressor s Recirculatio n Figure 12: Membrane Equipment Power Distribution (kwh/day) 8

9 Figure 13: ION 735 Meters Installed on Two Permeate 1, kw.h Usage Equivalent Average Pump Speed % 6% Pump Power Usage (kw.h) % 4% 3% 2% 1% Pump Speed (%) 4 % 2-Aug Aug-13 3-Sep-13 1-Sep Sep Sep-13 Figure 14: Permeate Pump Power and VFD Speed for Cycle 3 9

10 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. Performance Parameter Performance Required Unit for Liquidated Liquidated Damages Performance Achieved Net Liquidated Damages Damages per Unit Recovery (%) 95.5 $4, $ $6, 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 Table 1: Liquidated Damages (Net Savings of $4.6MM) 9 1 $78, 6 -$234, 1,169 1 $11, $3,78, $8, $ Varies Varies Varies Varies $229, $4,614,816 1

11 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. 1. 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!!! 11