Sustainable and Integrated Urban Water System Management

SANITASSustainable and Integrated Urban Water System Management

Towards a safe wastewater reuse: innovating in wastewater

reclamationSANITAS Final Conference

18 September 2015, Barcelona

Teresa de la Torre& Marina Arnaldos

Acciona Agua, R&D Department

Sustainable and Integrated Urban Water System Management

Introduction• >3 Billion people will live under water stress in 2025 (Valladares et al., 2014)• EIP Water: 8 priority areas, with 5 thematic priorities:

– Water reuse and recycling– Water and wastewater treatment– Water-energy nexus– Flood and drought risk management– Ecosystem services

• Barriers to water reuse: public perception, legislation, infrastructure, economical… but also technological:– Robustness– Energy consumption are still not convincing the end-users

Need for robust technologies that produce safe reclaimed water at competitive prices

Sustainable and Integrated Urban Water System Management

SANITAS approach• 2 different approaches:– Improvement of existing technologies: Membrane bioreactor optimization (MBR)– Development of emerging technologies: Forward osmosis MBR

Sustainable and Integrated Urban Water System Management

Membrane Bioreactor (MBRs) Robust, Low Footprint Process Suited for Water Reuse Purposes:-No patogens-No suspended solids-Low turbidity

High Energy Cost Membrane aeration for fouling control

(Adapted from Judd, 2011)

(Adapted from Krzeminski, 2013)

Energy consumption

Operational costs

Sustainable and Integrated Urban Water System Management

MBR optimization• Three actions for MBR operational costs reduction:

– Large bubble cap sparging– Optimal operational point

– Expert control system: • Adaptation of the aeration to the real-time conditions of the plant• Modelling and calibration performed during SANITAS• Control system implemented in the demo plant: LIFE-BRAINYMEM project (www.life-brainymem.com)

Sustainable and Integrated Urban Water System Management

MBR optimization results>1 year operation Almuñécar MBR demonstration plant:

0.71 kWh/m3 0.25 kWh/m3 0.16 kWh/m3 0.14 kWh/m3

Large bubbleCap sparging and new module

ConventionalMBR of 2006

Optimization operational parameters Expert control

62.5% reduction 40% reduction 15-20% reductionstill in evaluation

Sustainable and Integrated Urban Water System Management

Forward osmosisWhy FO?

– Low and reversible fouling (Less pretreatment, less chemical cleaning)– Improvements in FO membranes: higher fluxes and more providers

FO Challenges– Low fluxes– DS recovery is energy intensive and costly (salt leakage and incomplete DS recovery)– No data: main studies are lab-scale, synthetic feed, short term and batch Realistic studies are still needed

Sustainable and Integrated Urban Water System Management

FO-MBR

Pilot scale FO-MBR plant

• Continuous operation during one month per selected DS using real activated sludge

• Sustained long-term operation with minimal fouling

• No chemical cleaning• High DS losses Membrane test cell (CTA, HTI)

Sustainable and Integrated Urban Water System Management

FO Industrial wastewater• Requiring high quality and complex treatment• With fouling problems (requiring extensive pretreatment)• Applications with no DS separation• Residual heatMunicipal wastewater• Potable reuse: multibarrier concept is state of the art• Industrial• Agriculture (Boron, salinity, heavy metal removal)MBR

Market opportunities

• In the last 10 years, MBR energy consumption has been reduced by 50% (EOI, 2014)

• Global annual growth rate of 22.4 %• Asia Pacific and the Middle East will be leading

markets (Source: http://www.thembrsite.com)

Worldwater, Vol. 27, Issue 2

MBR predicted growth rate

Sustainable and Integrated Urban Water System Management

Conclusions• Water robust reclamation technologies have improved in the

last years (lower energy consumption, better membranes..)• SANITAS:

– MBR energy consumption in a demonstration plant reduced from 0,71 to 0,14 kWh/m3 (80% reduction!)

– FO-MBR showed stable operation with low fouling, DS recovery is still a matter of concern

• MBR technology has a bright future for wastewater reclamation

• FO is still emerging, but it is a promising choice for concrete applications

Sustainable and Integrated Urban Water System Management

Acknowledgement

www.sanitas-itn.eu

LIFE BRAINYMEM project www.life-brainymem.com

The research leading to these results has received funding from the People Program (Marie Curie Actions) of the European Union’s Seventh Framework Programme FP7/2007-2013 under REA agreement 289193.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.

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