Beatriz Corzo , del departamento de I+D de ACCIONA Agua, presentó la ponencia "Evaluation of a hybrid forward osmosis system for agricultural reuse of high salinity wastewater” en la conferencia anual que la asociación europea de desalación ha celebrado en Roma entre los días 22-26 de mayo de 2016.

1. EVALUATION OF A HYBRID
FORWARD OSMOSIS SYSTEM
FOR AGRICULTURAL REUSE OF
HIGH SALINITY WASTEWATER
EDS Desalination for the Environment:
Clean Water and Energy
22-26 May 2016
Presenter: Beatriz Corzo email: beatriz.corzo.garcia@acciona.com

2. ACCIONA Agua. Your partner in the water cycle
INDEX
Wastewater Reuse
Hybrid FO advantages
FO challenges
Ofrea Project
Design
Demonstration plant
Cost evaluation
Conclusions
Acknowledgments

3. ACCIONA Agua. Your partner in the water cycle
WASTEWATER REUSE
>3 Billion people will live under water stress in 2025 (Valladares
et al., 2014)
Options:
Water desalination
Water reuse
Improve water efficiency
Challenges for water reuse are both technological and
economical: technologies that can assure safe water at a
competitive price are needed
Can we compete using FO in water reuse for agricultural purposes?
A combination
of the three is
needed!

4. ACCIONA Agua. Your partner in the water cycle
HYBRID FO ADVANTAGES
Multibarrier concept
High permeate quality
Low and reversible fouling
Less pretreatment
Less chemical cleaning
Product water customization (e.g. boron removal,
fertigation)

5. ACCIONA Agua. Your partner in the water cycle
Low flux (ICP & ECP) and expensive elements
Improvements in FO membranes:
Thinner membranes with less tortuosity (S parameter) → less ICP and higher flux
More providers → lower prices
DS recovery is energy intensive.
Diluted DS has more osmotic pressure than feed water
DS replacement costs
Reverse salt diffusion and incomplete DS recovery
Permeate quality
DS content
No real data
Main studies are lab-scale, synthetic feed, short term and batch
conditions. Realistic studies are still needed → OFREA PROJECT
FO CHALLENGES

6. ACCIONA Agua. Your partner in the water cycle
OFREA PROJECT
According to a workshop on water reuse: (Optimizing water
reuse in EU. Dec 2014)
Water reuse in Spain: 35%
Region of Murcia: 98%
of wastewater is reused,
mostly in agriculture.
The rest presents high
salinity.
Reuse Datebase (CEDEX). R. Iglesias, 2007

7. ACCIONA Agua. Your partner in the water cycle
OFREA PROJECT
FO-NF pilot plant is operating with real feed, continuous
and long-term (> 1 year):
Feed water: San Pedro del Pinatar 3 m3/h WWTP
effluent
– Conductivity: 4-6 mS/cm
– Boron: 1.2 ppm
– SAR: 10.6
RD 1620/2007 limit:
– Conductivity: 3 mS/cm
– Boron: 0.5 ppm
– SAR: 6

8. ACCIONA Agua. Your partner in the water cycle
DESIGN OF DEMONSTRATION PLANT
It was presented in EUROMED Palermo and IDA San Diego 2015
Porifera PFO-100 was the FO membrane selected:
Three DSs were selected: organic and inorganic molecules
NF270-4040 or NF90-4040 from Filmtec were selected as recovery
membranes:

9. ACCIONA Agua. Your partner in the water cycle
DEMONSTRATION PLANT

10. ACCIONA Agua. Your partner in the water cycle
DEMONSTRATION PLANT DATA
Specific flux or permeability
FO=Flux/(пDS – пfeed)
NF=Flux/(NDP)
Stable operation of the FO
(22% of loss of flux the first
days)
NF permeability decreased
due to fouling:
Using an organic DS.
Using an inorganic DS
and increasing permeate
flowrate. Silicates and
gypsum presence.
A change in DS
A change in NF membranes
Fouling
A change in DS

11. ACCIONA Agua. Your partner in the water cycle
PERMEATE QUALITY
Stable permeate quality
Low conductivity except for
initial NF membranes
B < 0.4 mg/L (>70% removal)
High quality for agricultural
use!
A change in NF: savings in
chemical consumption
but more energy is used
A change in DS
A change in NF membranes
A change in DS

12. ACCIONA Agua. Your partner in the water cycle
COST EVALUATION
DS reposition and energy consumption
No chemical cleaning in FO membranes
DS
DS
Reposition
(Kg/m3)
DS Cost
(€/m3) (1)
Energy
Consumption
(KWh/m3)
Energy
Cost
(€/m3) (2)
Total
(€/m3)
Organic 0.9 2.50 4.57 (3) 0.46 2.96
Inorganic salt 1.71 1.68 3.44 0.34 2.02
Inorganic salt 0.99 0.97 4.46 0.45 1.42
New inorganic
salt
0.58 0.52 4.43 0.44 0.96
(1) DS price is referred to a small-scale order
(2) It is assumed 0.10€/KWh
(3) NF Membranes fouled
NF HF
NF HR

13. ACCIONA Agua. Your partner in the water cycle
CONCLUSIONS
FO-NF operated in the long term with real feed:
NF membrane was fouled with the organic DS and the first inorganic DS.
FO membrane is working with stable permeability. No fouling in the long-
term.
High permeate quality (conductivity, SAR and boron are below legislation).
Costs
Relevant cost due to DS losses and DS reconcentration energy.
New DS is CHEAPER and has ↑Van’t Hoff coefficient.
NF chemical cleaning is related to DS. No cleaning in FO membranes.
No remineralization is needed.
Economic feasibility of hybrid FO is highly dependent on the DS
selected. It could be cheaper than conventional systems!

14. ACCIONA Agua. Your partner in the water cycle
The research leading to these results has received funding
from the LIFE+ Programme of the European Commission
(LIFE12/ENV/ES/000632 LIFE OFREA) and from La Generalitat
de Catalunya (Industrial PhD program).
ACKNOWLEDGMENTS
All my colleagues from Acciona Agua and Carme
Sans from the University of Barcelona.