Presentation on theme: "Scott Reinert , P.E. Water Resources Manager El Paso Water Utilities"— Presentation transcript:
1Scott Reinert , P.E. Water Resources Manager El Paso Water Utilities Future of Desalination 2011 Annual Salinity Summit Multi-State Salinity CoalitionThe topic of my presentation is “Future of Desalination”My name is Scott Reinert.I am the Water Resources manager for El Paso Water UtilitiesI am giving this presentation on behalf of Ed Archuleta who cannot be here at the Conference because of a family emergency.Scott Reinert , P.E.Water Resources ManagerEl Paso Water Utilities
2Topics Current and future growth of desalination in the U.S. Research topicsDesalination research organizationsConclusion
3Growth of Desalination 1960’s: desalination had its commercial beginnings1980: 30 U.S. municipal desalination facilities with capacity of at least 25,000 gallons per day: management of concentrate through disposal (ocean outfall, sewer, deep well injection, evaporation ponds, irrigation)2000 to present: ZLD, beneficial use, volume reductionThis slide outlines some of the highlights in the growth of the Desalination industry.
4U.S. Municipal Desalination Plants Cumulative Number ofU.S. Municipal Desalination PlantsEstimated 340 PlantsEstimated 300 PlantsMunicipal Desalination Plants operating in U.S.that are at least 25,000 gallons per dayThis chart shows the number of U.S. municipal desalination plants with capacity of at least 25,000 gpd. This is equivalent to 17 gpm.
5Research Topics Irrigation return flows Recovering water from concentrateCartridge filtersCenter for Inland Desalination Systems (CIDs)Zero Discharge Desalination (ZDD)Capacitive DeionizationConcentrate Management
7Irrigation Return Flows (case study) Irrigation return flow is of lower quality than irrigation season (elevated TDS, sulfate, chloride)Winter flow during this time is approximately 10 MGDTreat 5 MGD of water with RO, blend with 5 MGD to produce 10 MGD1 MGD of concentrate into the riverConcept is included as a Water Management Strategy in the State Water Plan to be implemented in Additional 2,700 acre-feet annuallyThe water quality improves with higher flowsAt 10 mgdTDS-2292 mg/lSO mg/lCl-512 mg/l20 mgdTDS 1780MgdTDS mg/lHigh quality water could be produced from irrigation return flows.
8Recovering Water from Concentrate This photo shows the 5 RO skids at the Kay Bailey Hutchison Desalination plant.The next few slides will provide information on the different research we have been doing to evaluate recovering water from the concentrate.
9Recovering Water from Concentrate At full design capacity, Kay Bailey Hutchison Desalination Plant will generate 3 MGD of concentrate.Cost–benefit analysis of recovering potable water from the concentrate versus the cost of deep well injection.
10> > Concentrate Research Nano followed by RO Lime followed by RO (EPWU/BOR/TWDB)>Nano followed by ROLime followed by ROVSEPSWRO>presentinitial studies were conducted to evaluate silica removal from the RO concentrate using lime treatment.Untreated silica will foul the RO membranes.Lime was shown to be very effective at removing silica from the concentrate.More recent concentrate research has focussed on VSEP and SWRO.
11Recovering Water from Concentrate Lime Treatment Laboratory StudiesLime is effective for removing silica from RO and nanofiltration concentrates.Vibratory Shear Enhanced Processing (VSEP)Membrane treatment system using vibrating membranes to produce shear waves that reduce the potential for membrane fouling.Sea Water Reverse Osmosis (SWRO)RO membranes used for sea water used to remove salts from concentrate. Initial pilot testing done in batch mode.VSEP - vibratory shear enhanced processingIs a membrane treatment system utilizing vibrating membranes to produce shear waves that reduce the potential for fouling at the membrane surface.ADVANTAGESResistance to foulingAbility to handle water with high solids concentrationDISADVANTAGESExtra maintenance required for the system.SWROVery effective for recovering most of the water from the concentrate of the KBH desalination plant.A batch treatment system of concentrate would be difficult to operate.
12Recovering Water from Concentrate Automated Seawater Reverse Osmosis (ASWRO)Fully automated system that uses RO to remove salts from concentrate in batch mode.Automated Continuous Flow Seawater Reverse OsmosisFuture research topic.Automated continuous flow seawater reverse osmosis would be preferred.Research would be needed to evaluate feasibility of continuous flow.
13VSEP Pilot Test Unit - Single Membrane (from New Logic website)
14Picture of Small Seawater RO Unit Used for Conducting Initial Tests SWRO UnitFeed TankHeat ExchangerA heat exchanger was used to keep the feed solution from overheating.Concentrate from the KBH plant was put into 30 gallon feed tank, acid and anti-scalent were added.Concentrate recycled back to the feed tank until the desired recovery was achieved.Picture of Small Seawater RO Unit Used for Conducting Initial Tests
15Picture of Fully-Automated Batch Treatment Seawater RO System
16Cartridge FiltersCartridge filters used to filter the influent water prior to RO treatment.Membranes manufacturers will typically recommend using 5 micron (or smaller) cartridge filters to protect membranes.Frequent replacement of cartridge filters represents a significant operation and maintenance expense.Tight cartridge filters may be too conservative.
18Cartridge Filters (case study) EPWU evaluated cartridge filters ranging in size from 5 to 30 microns in a controlled laboratory environment.5 micron cartridge filter clogged more frequently than the larger sizes while not offering greater protection of the RO membrane.As a result of this case study, EPWU uses a 15 micron filter that requires fewer changeouts than the 5 micron filter.EPWU is saving $100,000 annually by using the 15 micron filter. No problems have been reported with using the larger cartridge filter.
19This is a picture of the laboratory set up at the KBH Desalination plant for the Cartridge Filter study.Cartridge Filters
20Center for Inland Desalination Systems (CIDS) Center for Inland Desalination Systems (CIDS) is a center that is studying desalination-related issues.CIDS has several regional partners, including UTEP, El Paso Water Utilities Public Service Board, Consortium for Hi-Technology Investigations in Water and Wastewater (CHIWAWA), and Veolia Water Solutions and Technologies.
21Center for Inland Desalination Systems (CIDS) Desalination-related issues studied by CIDSRecovery of concentrate produced during the desalination processDeveloping small-scale portable desalt equipment to be used in remote locationsDeveloping energy efficient water treatment technologies
22Zero Discharge Desalination (ZDD) ZDD offers the potential to maximize the volume of product water from a brackish source.This effort will be a partnership between UTEP, Veolia Water Solutions & Technologies, and the City of Alamogordo.ZDD technology is capable of desalination with yields as high as 97% using a proprietary silica removal system.High recovery processes are needed because of high waste disposal costs, limited water supply, and environmental concerns associated with brine.
23Capacitive Deionization CDI has been reported to potentially be a cost effective alternative to membrane technologiesLower energy requirement, no membrane fouling, no chemicals neededDuring the flow, the ions in the saline water move towards anion/cation exchange membranes depending upon the polarity of the ions.CDI has shown a lot of promise, but is not widely used because of the low water recovery ratio.
24Capacitive Deionization The schematic shows the capacitive deionization processIt is a process of using electric current, an exchange membrane to remove salts from water.Perhaps we will see more interest in this technique in the years ahead.
25Desalination Concentrate Management Policy Analysis - CHIWAWA Review and analysis of regulatory and policy barriers to concentrate management.Clean Water Act and Safe Drinking Water Act were established before desalination was widely utilized to produce usable water supplies.Recommendations will be made to facilitate development of brackish water desalination and concentrate management in the U.S.
26Desalination Research Organizations Multi-State Salinity CoalitionCHIWAWA (Consortium for High Technology Investment on Water and Wastewater)Water Reuse FoundationWater Research FoundationBureau of ReclamationTexas Water Development Board
27Conclusion Identify desalination research needs. Current state and federal funding for research is limited.Stakeholders have limited funding to participate in research projects.Effective partnershipsPool resources of matching funds and in-kind services to create opportunities for continued research.