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

2

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

3

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!

4

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

5

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!!

6

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!

7

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

8

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

9

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.

10

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?

11

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

12

IMPROVEMENT OF PRETREATMENT PROCESSES

Combination of membrane processes with adsorption processes

Improved performance both in algal bloom and normal conditions

Results from VETRA® Process

13

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

14

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

15

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

16

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

17

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

18

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

19

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

20

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

21

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