full-scale feasibility of the forward osmosis-mbr process for wastewater reclamation
TRANSCRIPT
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FULL-SCALE FEASIBILITY OF THE FO-MBR PROCESS FOR WASTEWATER RECLAMATION
M. Arnaldos, T. de la Torre, C. Rodríguez and J.J. MalfeitoOZWATER 2015, Adelaide (Australia)
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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
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FO technology has been receiving increased attention in the last years A wide variety of organizations are developing technological solutions for FO
© 2015 Acciona Agua S.A.U. All rights reserved.
Improvements in FO membranes: higher fluxes and increased performance
Increase in number of membrane providers: decrease in costs
Introduction: FO-MBR
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Introduction: The FO-MBR Technology
Forward Osmosis Membrane Bioreactor (FO-MBR)
(Coday, 2014)
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No need for membrane cleaning and scouringLower energy consumption
Reversible foulingConstant operational cost through time
High removal efficienciesEmerging contaminantsBoron
FO-MBR and DS recovery system = multibarrier treatment systemPotential for potable reuse?
Production of reclaimed water for different usesE.g. fertigation
© 2015 Acciona Agua S.A.U. All rights reserved.
Introduction: FO-MBR Potential
(Mi and Elimelech, 2009)
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Introduction: FO-MBR Challenges
Internal Concentration Polarization (ICP)Reduced Water FluxesSalt Concentration in Bioreactor
Draw Solution Selection and SeparationIncreased Operational Cost
Emerging TechnologyFeasibility Assessment
(Productivity, Energy Requirements, Fouling Occurrence)
(Achilli et al., 2010)
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Optimization of FO-MBR Operational ConditionsSelection of Promising DS Through Mathematical ModelingDifferent 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 ScaleExperimental Process EvaluationProcess Efficiency, Water Fluxes, Reverse Salt Transport,
Membrane Fouling
© 2015 Acciona Agua S.A.U. All rights reserved.
Research Objectives
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Materials and MethodsSelection of a Promising DS through Mathematical Modelling
J wC+J s=D effdCdx
Intrinsic properties of DSs:- Van’t Hoff
Coefficient (β)- Diffusion Coefficient
(D)
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Materials and MethodsExperimental 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)
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Flux
β
D
π
I.C.P.
Results and Discussion
Selection of a Promising DS through Mathematical Modelling
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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
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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)
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Main ConclusionsFO-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
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Industrial Waters• Requiring high quality and complex treatment• With fouling problems (requiring extensive pretreatment)• Applications with no DS separation
Municipal Waters for ReusePotable• 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!
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AcknowledgementsWe 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.