1. Peter Hillis, Water Treatment Technical Expert, UU
Engineering
Upgrading the longest
running microfiltration plant
in the UK

2. Outline
Background and History
Drivers for Change
Pilot Trials
Comparison Pilot vs. Full-Scale
Outcome
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3. Background and History
Lake District, NW England
59 Ml/d (15 MGD)
Cryptosporidium
Commissioned in late 1999
Longest running MF plant in
UK
This is a single source supply
– no alternatives
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4. Current Process Flow Diagram
Primary
Microfiltration
59 Ml/d
Pre-screen Contact Tank
17 x 90M10C
2 x 90M10C
Clarifier Secondary
Microfiltration
PACl
Tanker
3
2% Sludge

5. Intake at Ennerdale Lake
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6. Ennerdale WTW
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7. Ennerdale WTW
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8. Primary Membrane Operation
Backwash Interval – 60 minutes
Backwash Duration – 2.5 minutes
Monthly caustic clean (1.25%)
Six monthly Peroxide clean
Sulphuric acid clean as required (pH2)
Zero Discharge Site – no sewer or discharge to the Lake
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9. Secondary Membrane Operation
Feed to secondary units is blend of
• primary backwash water (20 mg/l )
• clarifier decant (5 - 25 NTU)
Clarifier is fed from blend of
• secondary backwash water (100 - 200 mg/l)
• neutralized CIP solution
Lake water low in dissolved solids (50 S/cm)
• coagulation sensitive to neutral CIP waste
Clarifier sludge 2%, 18 m³/day
• most difficult area, problems can shut plant
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10. Drivers for Change
Plant has operated successfully for over 10 years
Membrane life of PP >10 Years
Why change from something that works well?
Improved efficiency – power, chemicals, waste
Improved flexibility – operation
Improved waste treatment
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11. Historic Performance TMP and Flow
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12. Historic Performance Membrane Resistance
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13. Feed water quality 2000 to 2009
Manganese Aluminium
TOC (mg/l) Turbidity (NTU) Iron (ug/l)
(ug/l) (ug/l)
Average 1.09 0.68 26.61 6.67 38.57
Max 4.22 3.99 166 39 245
Min 0.25 0.12 5 2 14.24
Std Dev 0.48 0.48 18.25 5.26 22.89
No 241 171 171 191 171
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14. Pilot Trials – Main Plant Comparison
Pilot Plant Main Plant
PVdF Membrane PP Membrane
Siemens Memcor L10V Siemens Memcor M10C
23m2 membrane area per module 28m2 membrane area per module
Flux 73 lmh Design Flux 41 lmh
Backwash Interval – 60 minutes Backwash Interval – 60 minutes
Backwash Volume – 17 l/module Backwash Volume – 55 l/module
Backwash Duration – 2.5 mins Backwash Duration – 1.5 mins
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15. Pilot Plant Results
Run # Start Days TMP Resistance Flux BW Interval (Minutes)
Date (kPa) ( lm-2h-1 )
Run Start Run End Run Run
Start End
1 21/9/06 34 30 114 1.80 5.73 73 60
2 2/10/06 42 30 137 1.25 4.92 73 60
3 6/12/06 39 33 149 1.23 5.23 73 60
4 16/1/07 30 34 103 1.23 3.43 73 60
5 20/2/07 35 30 58 1.21 2.65 56 60
6 27/3/07 66 27 97 1.24 5.28 56 60
7 1/6/07 34 27 60 1.46 3.35 56 60
8 5/7/07 43 24 110 1.53 6.40 56 120
9 10/9/07 47 24 110 1.40 5.00 56 120
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16. Pilot Plant Results
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17. Pilot Plant Results
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18. Comparison with Full-scale
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19. Identified Benefits
Reduced energy
Reduced chemical consumption
Simplified CIP – Hypochlorite only
Reduced volumes to thickener – estimated at 25% the volume
with 4 times solids loading improving operation of thickener
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20. One Step Beyond?
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21. Copy of Presentation
Email Peter.Hillis@uuplc.co.uk
Download at LinkedIn.com
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22. Thank You
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