Marina Arnaldos (ACCIONA Agua) presented in OZ WATER 2015 "FULL-SCALE FEASIBILITY OF THE Forward Osmosis-MBR PROCESS FOR WASTEWATER RECLAMATION".

1. FULL-SCALE FEASIBILITY OF THE FO-MBR PROCESS FOR
WASTEWATER RECLAMATION
M. Arnaldos, T. de la Torre, C. Rodríguez and J.J. Malfeito
OZWATER 2015, Adelaide (Australia)

2. Index
1. Introduction and Objectives
2. Materials and Methods
3. Results and Discussion
• DS Selection
• Long-term FO-MBR Operation
• Preliminary Cost Evaluation
4. Conclusions

3. FO technology has been receiving
increased attention in the last years
A wide variety of organizations are
developing technological solutions for
FO
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Improvements in FO membranes:
higher fluxes and increased
performance
Increase in number of membrane
providers: decrease in costs
Introduction: FO-MBR

4. Introduction: The FO-MBR Technology
Forward Osmosis Membrane Bioreactor (FO-MBR)
(Coday, 2014)

5.  No need for membrane cleaning and scouring
 Lower energy consumption
 Reversible fouling
 Constant operational cost through time
 High removal efficiencies
 Emerging contaminants
 Boron
 FO-MBR and DS recovery system =
multibarrier treatment system
 Potential for potable reuse?
 Production of reclaimed water for different
uses
 E.g. fertigation
© 2015 Acciona Agua S.A.U. All rights reserved.
Introduction: FO-MBR Potential
(Mi and Elimelech, 2009)

6. Introduction: FO-MBR Challenges
 Internal Concentration Polarization
(ICP)
 Reduced Water Fluxes
 Salt Concentration in Bioreactor
 Draw Solution Selection and
Separation
 Increased Operational Cost
 Emerging Technology
 Feasibility Assessment
(Productivity, Energy
Requirements, Fouling
Occurrence)
(Achilli et al., 2010)

7.  Optimization of FO-MBR Operational Conditions
 Selection of Promising DS Through Mathematical Modeling
 Different Compositions and Concentrations of Draw
Solution (DS): Water Flux, ICP, Salt Accumulation in
Bioreactor
 Assess Long-Term Feasibility of FO-MBR for Activated
Sludge Treatment at Lab Scale
 Experimental Process Evaluation
 Process Efficiency, Water Fluxes, Reverse Salt Transport,
Membrane Fouling
© 2015 Acciona Agua S.A.U. All rights reserved.
Research Objectives

8. Materials and Methods
Selection of a Promising DS through Mathematical Modelling
JwC + Js = Deff
dC
dx
Intrinsic properties of
DSs:
- Van’t Hoff
Coefficient (β)
- Diffusion Coefficient
(D)

9. Materials and Methods
Experimental Process Evaluation
FO-MBR Pilot Plant
• Feed: 4L/min, 1 bar; DS: 1L/min, 0.5 bar.
• Continuous Operation (1 month/DS)
• Real Activated Sludge from MBR Biological
Reactor
Membrane test cell (CTA, HTI)

10. Flux
β
D
 π
 I.C.P.
Results and Discussion
Selection of a Promising DS through Mathematical Modelling

11. Results and Discussion
Selection of a Promising DS through Mathematical Modelling
• List of highly soluble
inorganic and organic
(>2 M) salts
• Discard salts with ions
regulated by
reclamation legislation
• Discard hazardous
substances
• Select a group with high
D & β coefficients

12. Results and Discussion
Selection of a Promising DS through Mathematical Modelling

13. Results and Discussion
K4P2O7 HCOOK
Experimental Process Evaluation

14. Preliminary Cost Comparison
© 2015 Acciona Agua S.A.U. All rights reserved.
- Comparison based on
cost of replacement for 6
LMH
- Other operational costs
would remain equal
- Replacement is due to
reverse salt flux and RO
effluent concentration
Potassium Pyrophosphate
is approximately 44%
cheaper from an
operational perspective
(Achilli et al., 2010)

15. Main Conclusions
 FO-MBR is an emerging low fouling technology
 Long-term operation without fouling was
demonstrated
 Reducing replenishment costs of DSs is an
important challenge
 Further search for DSs together with membrane
advances is required for full-scale feasibility

16. Industrial Waters
• Requiring high quality and complex treatment
• With fouling problems (requiring extensive pretreatment)
• Applications with no DS separation
Municipal Waters for Reuse
Potable
•Indirect
•Direct (Singapur/Namibia…)
Irrigation
•Boron
•Microcontaminants
•High TDS
•Heavy metals
Opportunities
Industrial
•Cooling towers
•Residual heat
Case-by-case analysis in order to determine appropriateness of FO solution!

17. Acknowledgements
We would like to thank ESAMUR and Aguas y Servicios de la Costa
Tropical for their collaboration.
The research leading to these results has received funding from:
• LIFE+ Programme of the European Commision
(LIFE12/ENV/ES/000632 LIFE OFREA) www.life-ofrea.com
• People Programme (Marie Curie Actions) of the European
Union’s Seventh Framework Programme FP7/2007-2015 under
REA agreement 289193 (SANITAS Project).
This presentation reflects only the author's views and the European Union is not liable for any use that may be made of the
information contained therein.

18. © 2015 Acciona Agua S.A.U. All rights reserved.