DESALINATION AS AN ALTERATIVE WATER SUPPLY
Chandra Mysore, Ph.D., PE, BCEE National Practice Leader – Water: GHD
7th Annual Georgia Environmental Conference, Water Management Practices and Georgia’s
Adopted Regional Water Plans,Session 5, Course 41
August 22 - 24, 2012
Presentation Overview
• Background
• Drivers of Desalination
• Challenges to Desalination
• Desalination Worldwide
• Australia-The Big Six
• Desalination in the US
• Conclusions
Major Commercial Processes • Distillation Processes
• Multi-Stage Flash (MSF)
• Multiple Effect Evaporation (MEE)
• Thermal or mechanical vapor compression (VC)
• Membrane Processes
• Nanofiltration, Reverse Osmosis (RO/SWRO)
• Electrodialysis Reversal (EDR)
WEFTEC 2008
REVERSE OSMOSIS
NANOFILTRATION
ULTRAFILTRATION
MICROFILTRATION
CONVENTIONAL FILTRATION
Sands
Algae and protozoans
Bacteria
Colloids
Humic acids
Metal ions
Pesticides
Dissolved salts
Sugars
Molecular weight
Viruses
Angström
MICRON
IONS MOLECULES MACRO MOLECULES MICRO PARTICLES MACRO PARTICLES
VISIBLE TO NAKED EYE OPTICAL MICROSCOPE SCANNING ELECTRON MICROSCOPE
Note : 1 Angström = 10-10 meter = 10-4 micron
Membrane Processes
Desalination History • Aristotle described distillation - 400 BC • Distillation: Desalination on early ships - 200AD • Distillation: MED (Norbert Rillieux, 1806 - 1894) • Coolgardie Water Distillery (WA) - 1895 • Distillation: Desalination MSF - 1956 • Distillation: Desalination MED - 1960 • Distillation: Desalination MVC, METC – 1960 • Membrane: RO (Drs. Sourirajan & Loeb @ UCLA, 1959) • Membrane: RO (John Cadotte - FilmTec, 1970) • Membrane: Desalination RO and NF - 1970 • Membrane: Pre-treatment (MF, UF) - 1990 • Membrane: Wastewater (MBR) - 2000
Dr. Sid Loeb
• Advances in RO Membrane Technology
• Greater salt rejection, Higher fluxes, Better fouling resistance
• Advances in system design, Larger diameter modules
• Lower Costs
• Improvements in membrane pre-treatment
• Conventional (SDI= 2-3.5); MF/UF (SDI < 2.0)
• Energy Cost Reduction
• Energy Recovery Devices; Low Pressure SW and BWRO
• Warmer Power Plant Water as Feed Source
DRIVERS OF DESALINATION
DRIVERS OF DESALINATION
• Trend towards co-location with power plants
• Advantages • Existing ocean intake and discharge pipelines • Warm water feed from cooling tower blowdown • Coastal property access • Reduces infrastructure, energy costs • Minimizes SWRO plant size • Dilution of concentrate stream • Favourable power rates
CHALLENGES TO IMPLEMENTING DESALINATION
• Environmental • Regulatory • Water Quality • Concentrate Disposal
• Membrane Fouling • Post-treatment, Corrosion • Public Perception • Industry Conservatism • Costs
Scanning Electron Micrographs
Organics Scale Biofilm Particulates
CONCENTRATE DISPOSAL
Australia’s six big desalination plants
The Big
Plant Capacity (mgd)
Status Dist Pipeline (miles)
Ave annual rainfall (in)
1 Sydney 66 Operating 15.5 45
2 Gold Coast 33 Operating 15.5 45
3 Perth I (Kwinana) 33 Operating 16 31
4 Victoria 107 Under const. 52 21
5 Adelaide 36 Under const. 27 20
6 Perth II (Binningup) 33 Under const. 66 31
5 6
3 2
1
4
The Seawater Reverse Osmosis (SWRO) Desalination Process
Perth’s Water Crisis The West Australian – Saturday 27 November 2010
Perth Seawater Desalination Plant (Perth I) - 38 mgd
• Client: Water Corporation • Capacity: 38 mgd • Plant Capital Cost: $266 million • Connecting System (IWSS): $51 million • Total Capital Cost: $317 million • Total Operating Cost: $16 million/year • Unit Cost: $1,172/AF (AU$1.00/m3)
• Commissioning Completion: 2007 • GHD Involvement: Production of Basis of Design and Basis of Construction
Documents, 3rd Party Review of Designs from both Competing Consortia, Durability Reviews During Design and Construction Phase, Integration Network Concept and Detailed Design including the largest Pumping Station in the Perth Integrated System, the Nicholson Road Pumping Station (10 MW). Seaglider Oceanographic Measurements
• Configuration: Open Intake, Diffuser Outfall, Travelling Band Screens, Dual Media Pressure Filtration, 5 Micron Cartridge Filtration, 2 Pass SWRO System, Lime and CO2 Re-mineralisation
• Seawater Feed Quality: 35000 – 38000 mg/L TDS • Product Water Quality: < 200 mg/L • Specific Energy Consumption (SEC): < 13.58 (13.18) kWh/kgal - 3.59 (3.48) kWh/m3) • Technology Contractor: Degremont (France/Spain) • Awards: GWI Membrane Desalination Plant of Year 2006
ERI Awarded GWI Environmental Contribution of the Year 2006
The Big Six – No. 1
Courtesy of Water Corporation Seawater Intake
Pre-treatment
SWRO & BWRO
Remineralisation/Storage
Potable water pump station
Residuals Treatment
Brine discharge
HV substation
Admin/Lab
Chemical Storage
Aerial View of Desalination Plant
Raw Seawater screen and pump station
Brine discharge
Seawater Desalination Initiative in the US Utility/Corp. Location Capacity
(MGD) Cost ($/Kgal)
Tampa Bay Water
Tampa, FL 25 2.40
San Diego County Water
Authority
Carlsbad, CA 50* 2.75
Poseidon Resources
Huntington Beach, CA
50* 2.85
LADWP Los Angeles, CA
12 3.13
West Basin El Segundo, CA
20 2.74
Orange County
Dana Point, CA
25 2.60-3.05
Brackish Water Desalination in the US Utility/Corp. Location Capacity
(MGD) Process
City of North Miami Beach,
FL
North Miami Beach, FL (Norwood
WTP)
17 to 32 9 MGD NF (Biscayne) 6 MGD RO (Floridan)
Aquaria Water/City of
Brocton
Taunton, MA 5 Immersed UF + Enh. Coag.
+ RO
Town of Jupiter
Jupiter, FL 14.5 RO
City of Simi Valley
Simi Valley, CA
1.0 RO
City of Sherman
Sherman, TX 10 Conventional + EDR
Hilton Head Hilton Head, SC
3 to 6 RO
COST STRUCTURE FOR SWRO
Fixed Charges 37%
Membrane Replacement 5%
Labor 4% Maintenance and Parts
7%
Consumables 3%
Electric Power 44%
SWRO COST STRUCTURE
Treatment cost for fresh water from a conventional water treatment plant $0.30-0.40/1000 gallons Imported Water from MWD, CA $1.50/1000 gallons Reclaimed water for industry in Southern California $2.22/1000 gallons Treatment cost for desalinated brackish water for residential use $1-3/1000 gallons Treatment cost desalinated seawater Santa Barbara, CA (1992) $5.50/1000 gallons Desalination Cost (2000-now) $2.45-3.40/1000 gallons Tampa Bay (2001) $2.40/1000 gallons Thermal Desalination $2.85-5.70/1000 gallons
FUTURE TRENDS
• Economy of Scale • 16” Elements:-3-6X area, flow of 8” Elements
• Energy Recovery Devices • Turbochargers • Pressure Exchangers
• Nanotechnology • Increases permeability by 75% • Better rejection • Energy Reduction (25%) • Biocidal Properties
CONCLUSIONS • There is no “silver bullet” solution to the nation’s future water
challenges (e.g. drought, increased salinity, ever-increasing demand).
• Desalination, as an alternative water supply, can meet a substantial component of US’s water supply needs.
• The amount of energy necessary to operate desalination plants will continue to decrease as membrane efficiencies increase and newer products enter the market.
• Sophisticated and sustainable seawater desalination plants will be the future trend using alternative forms of energy (e.g. wind power, solar energy etc).
GHD | CLIENTS | PEOPLE | PERFORMANCE
Chandra Mysore, National Practice Leader - Water Ph.D., PE, BCEE
T 301 275 5770| [email protected] http://www.ghd.com
GHD serves the global markets of: Infrastructure | Mining & Industry | Defence | Property & Buildings | Environment
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