An Assessment of Subsurface Intake Systems: Planning and Impact on Feed Water Quality for SWRO Facilities

Handle URI:
http://hdl.handle.net/10754/626335
Title:
An Assessment of Subsurface Intake Systems: Planning and Impact on Feed Water Quality for SWRO Facilities
Authors:
Dehwah, Abdullah ( 0000-0002-0495-7577 )
Abstract:
Subsurface intake systems are known to improve the feed water quality for SWRO plants. However, a little is known about the feasibility of implementation in coastal settings, the degree of water quality improvements provided by these systems, and the internal mechanisms of potential fouling compounds removal within subsurface intake systems. A new method was developed to assess the feasibility of using different subsurface intake systems in coastal areas and was applied to Red Sea coastline of Saudi Arabia. The methodology demonstrated that five specific coastal environments could support well intake systems use for small-capacity SWRO plants, whereas large-capacity SWRO facilities could use seabed gallery intake systems. It was also found that seabed intake system could run with no operational constraints based on the high evaporation rates and associated diurnal salinity changes along the coast line. Performance of well intake systems in several SWRO facilities along the Red Sea coast showed that the concentrations of organic compounds were reduced in the feed water, similar or better than traditional pretreatment methodologies. Nearly all algae, up to 99% of bacteria, between 84 and 100% of the biopolymer fraction of NOM, and a high percentage of TEP were removed during transport through the aquifer. These organics cause membrane biofouling and using well intakes showed a 50-75% lower need to clean the SWRO membranes compared to conventional open-ocean intakes. An assessment of the effectiveness of seabed gallery intake systems was conducted through a long-term bench-scale column experiment. The simulation of the active layer (upper 1 m) showed that it is highly effective at producing feed water quality improvements and acts totally different compared to slow sand filtration systems treating freshwater. No development of a “schmutzdecke” layer occurred and treatment was not limited to the top 10 cm, but throughout the full column thickness. Algae and bacteria were removed in a manner similar to slow sand filtration, but it took many months to produce consistent reductions in NOM fractions and TEP. The data suggested that a thicker active layer (2m) is needed to facilitate a more rapid reduction in the main potential fouling organics.
Advisors:
Ng, Kim Choon ( 0000-0003-3930-4127 )
Committee Member:
Missimer, Thomas M.; Peinemann, Klaus-Viktor ( 0000-0003-0309-9598 ) ; Ghaffour, Noreddine ( 0000-0003-2095-4736 ) ; Amy, Gary
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Program:
Environmental Science and Engineering
Issue Date:
Dec-2017
Type:
Dissertation
Appears in Collections:
Dissertations

Full metadata record

DC FieldValue Language
dc.contributor.advisorNg, Kim Choonen
dc.contributor.authorDehwah, Abdullahen
dc.date.accessioned2017-12-10T11:47:29Z-
dc.date.available2017-12-10T11:47:29Z-
dc.date.issued2017-12-
dc.identifier.urihttp://hdl.handle.net/10754/626335-
dc.description.abstractSubsurface intake systems are known to improve the feed water quality for SWRO plants. However, a little is known about the feasibility of implementation in coastal settings, the degree of water quality improvements provided by these systems, and the internal mechanisms of potential fouling compounds removal within subsurface intake systems. A new method was developed to assess the feasibility of using different subsurface intake systems in coastal areas and was applied to Red Sea coastline of Saudi Arabia. The methodology demonstrated that five specific coastal environments could support well intake systems use for small-capacity SWRO plants, whereas large-capacity SWRO facilities could use seabed gallery intake systems. It was also found that seabed intake system could run with no operational constraints based on the high evaporation rates and associated diurnal salinity changes along the coast line. Performance of well intake systems in several SWRO facilities along the Red Sea coast showed that the concentrations of organic compounds were reduced in the feed water, similar or better than traditional pretreatment methodologies. Nearly all algae, up to 99% of bacteria, between 84 and 100% of the biopolymer fraction of NOM, and a high percentage of TEP were removed during transport through the aquifer. These organics cause membrane biofouling and using well intakes showed a 50-75% lower need to clean the SWRO membranes compared to conventional open-ocean intakes. An assessment of the effectiveness of seabed gallery intake systems was conducted through a long-term bench-scale column experiment. The simulation of the active layer (upper 1 m) showed that it is highly effective at producing feed water quality improvements and acts totally different compared to slow sand filtration systems treating freshwater. No development of a “schmutzdecke” layer occurred and treatment was not limited to the top 10 cm, but throughout the full column thickness. Algae and bacteria were removed in a manner similar to slow sand filtration, but it took many months to produce consistent reductions in NOM fractions and TEP. The data suggested that a thicker active layer (2m) is needed to facilitate a more rapid reduction in the main potential fouling organics.en
dc.language.isoenen
dc.subjectSubsurface intakeen
dc.subjectBiofoulingen
dc.subjectSWRO desalinationen
dc.subjectWell intake systemsen
dc.subjectseabed intake systemsen
dc.subjectnatural pretreatmenten
dc.titleAn Assessment of Subsurface Intake Systems: Planning and Impact on Feed Water Quality for SWRO Facilitiesen
dc.typeDissertationen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen
dc.contributor.committeememberMissimer, Thomas M.en
dc.contributor.committeememberPeinemann, Klaus-Viktoren
dc.contributor.committeememberGhaffour, Noreddineen
dc.contributor.committeememberAmy, Garyen
thesis.degree.disciplineEnvironmental Science and Engineeringen
thesis.degree.nameDoctor of Philosophyen
dc.person.id113232en
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