Concentrate and permeate treatment processes for improving the sustainability
of inland brackish water desalinationW. Shane Walker, Ph.D.Anthony Tarquin, Ph.D.
Center for Inland Desalination SystemsThe University of Texas at El Paso
Multi-State Salinity Coalition SummitLas Vegas, NevadaJanuary 26, 2012
Objectives
• Review indicators of sustainability• Highlight several CIDS investigations
demonstrating improved sustainability
Sustainability
Environmental
EconomicSocio-Political
Environmental
EconomicSocio-Political
Select Sustainability Indicators
• Higher water recovery (product/feed)• Lower specific energy consumption (kWh/kgal)• Less chemical consumption, waste production• Lower economic cost ($/kgal; $/MGD)• Technical/operational complexity
Inland Membrane Desalination
Brackish Water Source
pretreatment membrane process
concentrate treatment
permeate treatment
Distribution
Reuse/Disposal
Permeate Treatment
Brackish Water Source
pretreatment membrane process
concentrate treatment
permeate treatment
Distribution
Disposal
Permeate Stabilization by Calcite
Three-step process1. Lower pH with CO2
– Relatively abundant and inexpensive gas2. CO2 reacts with calcite– CO2 + CaCO3 → Ca2+ + 2 HCO3-
3. Add small dose of base for LSI > 0
Carollo Engineers, Inc. and Shane Walker, UTEPTexas Water Development Board (1004831105)
Permeate Stabilization by Calcite
• Feed: KBH permeate• TOMCO2: pH 5.6-5.7• Upflow calcite contactor
– Media: 0.5-2 mm particles– EBCT: 1-10 min– Overflow: 2-17 gal/ft2/min
• Product Quality:– pH: 7.5-8.5– Ca2+: 20-30 mg/L– ALK: 50-75 mg/L (as CaCO3)– LSI: -0.5-0.0
• Energy: < 0.1 kWh/kgal
Carollo Engineers, Inc. and Shane Walker, UTEP CIDSTexas Water Development Board (1004831105)
Concentrate Treatment
Brackish Water Source
pretreatment membrane process
concentrate treatment
permeate treatment
Distribution
Disposal
CERROAnthony Tarquin, UTEP
US Bureau of Reclamation, DWPR R10AP81217
concentrate Seawater RO Distribution
• Concentrate Enhanced Recovery RO (CERRO)• Batch-continuous seawater RO process
exploiting induction time of precipitation
CERRO
• Demonstrated at KBH (El Paso) and BGNDRF (Alamogordo)
• Feed: KBH- >10,000 mg/L BGNDRF- 6000 mg/L
• Product Flow: 1 gpm• Recovery: KBH- 97%
BGNDRF (ongoing)
• Energy: 6-7 kWh/kgal (w/ energy recovery)
Anthony Tarquin, UTEPUS Bureau of Reclamation, DWPR R10AP81217
Zero Discharge Desalination (ZDD)
• Demonstrated at KBH (El Paso) and BGNDRF (Alamogordo)
• BGNDRF Feed: 2500 mg/L• NF/RO and Electrodialysis
Metathesis (EDM)• Product Flow: 20 gpm• Recovery: 97-98%• Energy: 6.6 kWh/kgal
Tom Davis & Malynda Cappelle, UTEPUS Bureau of Reclamation, DWPR R10AP81212
Conclusions
Sustainability of inland brackish water desalination can be improved by:– increasing system recovery– reducing specific energy consumption– reducing chemical consumption and production– reducing economic cost– designing appropriate technical complexity
Acknowledgements
• Permeate Stabilization by Calcite– Texas Water Development Board– El Paso Water Utilities, KBH Desalination Plant– Carollo Engineers: Winnie Shih, Bradley Sessions, Justin Sutherland– UTEP CIDS: Luis Maldonado, Cora Martinez, Sami Al-Haddad
• CERRO (High Recovery)– US Bureau of Reclamation, BGNDRF (Alamogordo, NM)– UTEP CIDS: Anthony Tarquin, Guillermo Delgado
• ZDD (High Recovery)– US Bureau of Reclamation, BGNDRF (Alamogordo, NM)– UTEP CIDS: Tom Davis, Malynda Cappelle, Lucy Camacho,
Noe Ortega, Jesse Valles
Questions or Comments
W. Shane Walker, Ph.D.Assistant ProfessorThe University of Texas at El Paso500 W. University Ave., Civil EngineeringEl Paso, TX 79968(915) [email protected]
