1. Nanofiltration Membrane
Pilot Studies for
Disinfection By-Product
Control
by Eric Lynne, EIT
 B.S. – Civil and Environmental Engineering
(2007) South Dakota State University

2. Introduction
 Objective
 Preliminary Tests
 Screening Tests
 Large Scale Pilot Tests
 Conclusions

3. (Bergantine 2007)

4. Restrictions
 Stage 2 D/DBP Rule
< 80 μg/L TTHM
< 60 μg/L HAA5
 Big Sioux River
< 1000 mg/L TDS
 Energy Efficient
High Flow at Low Applied Pressure

5. Background
 DBP Problem
 Treatment Methods:
Chloramination
NF Membranes
 Pilot Plant Testing

6. Background
 Chloramination
Low DBPs Created
Effective

7. Background –
Spiral Wound Membrane
(Hydranautics 2008)
1 2 3
4 5

8. Background
 Membranes
Permeate
Concentrate
Recovery
Stages
(AWWA 1999)

9. Nanofiltration
Permeate
Concentrate
(AWWA 1999)

10. Background
 Membrane Problems
Inorganic Scaling
Organic Fouling
Microbial or Silt
Fouling
(Malki 2008, Dow 2008)

11. Preliminary Testing
 Water Quality
TOC
UV254
SDI
Ammonia
 Chloramination

12. Preliminary Testing
 Results
Water Quality
• Well Specific
• UV254  TOC
• SDI: Raw < 5; Feed ~ 1
• Naturally occuring ammonia
a) WTP Influent
b) Filter Effluent

13. Chloramination
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
0 1 2 3 4 5 6 7 8 9 10 11 12
Chlorine : Ammonia Ratio
Residual(mg/L)
Free Chlorine Total Chlorine
MonoChloramine Free Ammonia

14. Chloramination
56, 59 μg/L TTHM

15. Chloramination
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
0 1 2 3 4 5 6 7 8 9 10 11 12
Chlorine : Ammonia Ratio
Residual(mg/L)
Free Chlorine Total Chlorine
MonoChloramine Free Ammonia

16. Chloramination
56, 59 μg/L TTHM
10 μg/L TTHM

17. Preliminary - Conclusions
 Source Water for NF Pilot Plant
 Direct Nanofiltration of raw water is feasible
 Filter Effluent is preferred
 Chloramination
 viable alternative with 82% TTHM reduction

18. NF Membrane Pilot Plants
 Phase I – Screening
Koch TFC-SR2 (K2)
Koch TFC-SR3 (K3)
Trisep XN45-TSF (T)
Hydranautics ESNA1-LF (HE)
Hydranautics HydraCoRe-70pHT (HH)
Dow/Filmtec NF270 (DF)
(Trisep 2008)

19. Phase I – Screening
 Hold flux constant
 Vary recovery for each membrane tested

20. Phase I – Results
 TOC and UV254 removal
NF Membrane and Percent Recovery
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
15 50 80 15 50 80 15 50 80 15 50 80 15 50 80 15 50 80
K2 K3 T HE HH DF
PercentRemoval
TOC UV254

21. Phase I – Results
 TTHM reduction
NF Membrane and Percent Recovery
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
15 50 80 15 50 80 15 50 80 15 50 80 15 50 80 15 50 80
K2 K3 T HE HH DF
PercentRemoval 87% Minimum Rejection Allowed

22. Phase I – Results
 Concentrate TDS concentration
0
200
400
600
800
1000
1200
K2 K3 T HE HH DF
NF Membrane
TotalDissolvedSolids(mg/L)
Disposal limit
1000 mg/L

23. Phase I - Conclusions
Membrane TDS < 1000 mg/L >87% TTHM reduction
Koch TFC-SR2 NO NO
Koch TFC-SR3 NO YES
Trisep XN45-TSF YES YES
Hydranautics ESNA1-LF NO YES
HydraCoRe-70pHT YES NO
Dow/Filmtec NF270 NO YES

24. Phase II
 85% recovery
 Variable Flux: 9, 12, 15 gfd
 Determine design criteria

25. Photographs of Pilot Plant

26. Phase II - Results
 TOC and UV254 removal
50%
55%
60%
65%
70%
75%
80%
85%
90%
95%
100%
9* 12 15 9 12 15 9 12 15
K3 T HE
NF Membrane and Flux Rate (gfd)
PercentRemoval
TOC UV254

27. 50%
55%
60%
65%
70%
75%
80%
85%
90%
95%
100%
9* 12 15 9 12 15 9 12 15
K3 T HE
NF Membrane and Flux Rate (gfd)
PercentReduction
Phase II - Results
 TTHM reduction
87% Minimum
Rejection Allowed

28. Phase II - Results
 Adjusted Specific Flux
0.00
0.05
0.10
0.15
0.20
0.25
9* 12 15 9 12 15 9 12 15
K3 T HE
NF Membrane and Flux Rate (gfd)
AdjustedSpecificFluxto25°C(gfd/psi)

29. Phase II - Results
 Ammonia (NH3-N) Removal
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
9* 12 15 9 12 15 9 12 15
K3 T HE
NF Membrane and Flux Rate (gfd)
PercentRejection

30. Phase II – Results
 Fouling
0
0.05
0.1
0.15
0.2
0.25
0 100 200 300 400 500 600 700 800
Hours
AdjustedSF(gfd/psi).
T HE

31. Phase II – Results
 Fouling
0
50
100
150
200
250
300
350
400
0 5 10 15 20 25 30
Days
Conductivity(μS/cm)
TriSep XN45-TSF
Hydranautics ESNA1-LF

32. Phase II - Conclusions

Blend Ratio: 44%/56%
 Concentrate TDS Increased
 SF decreased with increasing flux
 Design Criteria
 Applied pressures ranged from 64-165 psi
 Specific flux values ranged from 0.13-0.21 gfd/psi
 System recovery rate of 85%
 Permeate TTHM values ranging from 1.1-2.5 μg/L
 No substantial fouling observed

33. Phase II - Conclusions
 Highest Specific Flux = Trisep XN45-TSF
 Highest TTHM rejection = Hydranautics ESNA1-LF
Membrane Optimum Setting Costs
Koch TFC-SR3 __ gfd ??
Trisep XN45-TSF __ gfd ??
Hydranautics ESNA1-LF __ gfd ??

34. Recommendations
 Cost Data
 Verify 15 gfd @ 80% recovery
 Select Hydranautics ESNA1-LF
15 gfd @ 85% recovery (costs?)
 Consistent Source Water
 One Membrane for Phase II
 Challenge Membrane to Foul

35. Questions