The 13th IWA Leading Edge Conference on Water and Wastewater Technologies
DEVELOPMENT AND APPLICATION OF SUSTAINABLE MEMBRANE DESALINATION TECHNOLOGY: REVERSING WATER SCARCITY AND FAST FORWARDING TO THE FUTURE
POTENTIAL INNOVATIONS IN CONVENTIONAL DESALINATION SYSTEMS: APPLICATION EXAMPLES
MARINA ARNALDOS
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INDEX
Background
Enhancing the Sustainability of Desalination
Improvement of Pretreatment Systems
Enhanced Monitoring and Control of Reverse Osmosis
Implementation of Discharge Treatment and Reuse Systems
Use of Renewable Energies
Conclusions
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BACKGROUND
Fresh water scarcity
Increased water demand- Growing population- Increased living standards- Industrialization
Climate change- Variation in natural systems
Need for a sustainable and economical water treatment technology!
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BACKGROUND
Seawater and brackish water desalination are obvious options to fulfill water needs
Reverse osmosis accounts for the majority of water desalinated worldwide due to its relative energy efficiency
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BACKGROUND
Remaining challenges in RO desalination:- Reduced energy
consumption- Reduced chemical
consumption- Reduced waste
discharge- Reduced water waste
In summary…- Improved economics- Improved sustainability
And let’s not forget non-technical challenges!!
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BACKGROUND
Energy and chemical consumption are intimately linked to the fouling ocurring in the membrane processes of the systems, both pretreatment and RO- Particulate fouling- Colloidal fouling- Scaling- Biofouling- Organic fouling
PERVASIVE AND YET TO BE FULLY ADDRESSED!
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BACKGROUND
NORMAL SEAWATER
ALGAE BLOOM
• Building Blocks
• Low Molecular Weight Acids
• Neutral Substances of Low
Molecular Weight
• Biopolymers
• Humic substances
• Polysaccharides (mainly)
BIOFOULING
ORGANIC FOULING
Different Compounds
Algal EPS
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BACKGROUND
Discharge of waste is caused due to: - Brine production in the RO process- Cleaning wastewaters from both pretreatment and RO
systems
Common disposal options: surface water discharge, deep well injection, evaporation ponds and land application
Economic drive to reduce the volume of waste discharged and disposal costs
Environmental drive to save water and reduce environmental pollution
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ENHANCING THE SUSTAINABILITY OF DESALINATION
Optimizing Current Solutions
Improvement of pretreatment processes for colloidal and dissolved organic matter removal
Enhanced monitoring and control of the RO process
Implementation of discharge treatment systems
Use of renewable energies
Implementing Emerging Solutions
Forward osmosis Membrane distillation Humidification-
Dehumidification Adsorption desalination Microbial desalination cell Etc.
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IMPROVEMENT OF PRETREATMENT PROCESSES
Conventional processes Coagulation-flocculation Sedimentation/Flotation Filtration Microbial inactivation
(chlorine, chlorine dioxide, bisulphite,…)
Dispersant/antiscalant addition
State of the art Microfiltration Ultrafiltration Nanofiltration
HOW DO WE MOVE FORWARD?
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IMPROVEMENT OF PRETREATMENT PROCESSES
Improved hydraulic design of flotation processes for higher load and lower energy consumption
Improved design of air diffusers and contact zone
Design for low-pressure air diffusing systems
Improved design of water and sludge collection areas
ULTRADAF®-EVO Design
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IMPROVEMENT OF PRETREATMENT PROCESSES
Combination of membrane processes with adsorption processes
Improved performance both in algal bloom and normal conditions
Results from VETRA® Process
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IMPROVEMENT OF PRETREATMENT PROCESSES
High flux operation of ultrafiltration processes
Estimated Response SurfaceFlux=120 LMH and Time for CEB=5 hours
Filtration Time (min) Backwash Time (sec)
Lower amount of membranes required
Decreased backwash times
Data from HIFLUS Process
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ENHANCED MONITORING AND CONTROL OF REVERSE OSMOSIS
Development of novel online sensors that provide information on the biofouling of membranes
Data from HYDROBIONETS Platform
Decreased operational pressure
Cleanings adapted to process requirements
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ENHANCED MONITORING AND CONTROL OF REVERSE OSMOSIS
Implementation of Big Data to develop better RO system models, controls and operational rules
Design Detail of the DESALMOD Platform
Adaptation of operation to feed and process conditions
Improved control over process failures
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IMPLEMENTATION OF WASTEWATER TREATMENT AND REUSE SYSTEMS
Brine reuse for ultrafiltration pretreatment cleaning operations
FILTERED WATERBRINE
Data from HIFLUS Process
Savings in backwash cleaning waters
Reuse of generated brine
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IMPLEMENTATION OF WASTEWATER TREATMENT AND REUSE SYSTEMS
Concentration of cleaning wastewaters from pretreatment processes
Detail of VERDI® Pilot Plant
Recovery of backwash cleaning waters
Concentration of generates waste flows
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IMPLEMENTATION OF WASTEWATER TREATMENT AND REUSE SYSTEMS
Treatment of reverse osmosis cleaning waters through advanced oxidation technologies for onsite irrigation reuse
Estimated Response Surface
Data from CLOSED LOOP Process
Recovery and reuse of RO cleaning waters
Reduced discharge of waste flows
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USE OF RENEWABLE ENERGIES
Renewable energies can power current and improved desalination systems
Desalination Plant in Adelaide, AustraliaCapacity: 300,000 m3/dayPlant designed to be renewables-fueled
Lower dependence on conventional fuel sources
Implementation of desalination in isolated locations
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CONCLUSIONS
State of the art membrane technology can be further optimized to address current challenges and improve the overall sustainability of desalination
Pretreatment systems can be combined with other processes for improved performance
Significant energy and chemical savings can be achieved through improved monitoring and control of the RO process
Waste discharge can be lowered through further treatment and onsite reuse can be achieved
Renewable energies can be added to the sustainability mix
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Location: Torrevieja, Alicante (Spain)Capacity: 240,000 m3/dayBiggest in Europe, largest in Spain
Location: Girona, Cataluña (Spain)Capacity: 20 m3/day Testing of new processes by R&D
Novel Developments
Innovation Opportunities