Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment

Handle URI:
http://hdl.handle.net/10754/623684
Title:
Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment
Authors:
Dehwah, Abdullah ( 0000-0002-0495-7577 ) ; Missimer, Thomas M.
Abstract:
Seabed gallery intake systems used for seawater reverse osmosis facilities employ the same principle of water treatment as slow sand filtration in freshwater systems. An investigation concerning the effectiveness of the active layer (top layer) in improving raw water quality was conducted by using a long-term bench-scale columns experiment. Two different media types, silica and carbonate sand, were tested in 1 m columns to evaluate the effectiveness of media type in terms of algae, bacteria, Natural Organic Matter (NOM) and Transparent Exopolymer Particles (TEP) removal over a period of 620 days. Nearly all algae in the silica sand column, 87% (σ = 0.04) of the bacteria, 59% (σ = 0.11) of the biopolymer fraction of NOM, 59% (σ = 0.16) of particulate and 32% (σ = 0.25) of colloidal TEP were removed during the last 330 days of the experiment. Total removal was observed in the carbonate sand column for algal concentration, while the bacterial removal was lower at 74% (σ = 0.08). Removal of biopolymers, particulate and colloidal TEP were higher in the carbonate column during the last 330 days with 72% (σ = 0.15), 66% (σ = 0.08) and 36% (σ = 0.12) removed for these organics respectively. Removal of these key organics through the 1 m thick column, representing the active layer, will likely reduce the rate of biofouling, reduce chemical usage and minimize operating cost in SWRO systems. The data show that the media will require several months at the beginning of operation to reach equilibrium so that high organic removal rates can be achieved. No development of a “schmutzdecke” layer occurred. The experimental results suggest that unlike freshwater slow sand filtration wherein most water treatment occurs in the upper 10 cm, in seawater systems treatment occurs throughout the full active layer depth of 1 m. The results of this study will help in designing and operating seabed gallery intake systems in varied geological conditions.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC)
Citation:
Dehwah AHA, Missimer TM (2017) Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment. Water Research 121: 95–108. Available: http://dx.doi.org/10.1016/j.watres.2017.05.014.
Publisher:
Elsevier BV
Journal:
Water Research
Issue Date:
11-May-2017
DOI:
10.1016/j.watres.2017.05.014
Type:
Article
ISSN:
0043-1354
Sponsors:
Funding for this research was provided by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors thank the Water Desalination and Reuse Center for the use of analytical equipment. Thanks are also extended to Ulrich Buttner for helping in designing the columns and Christiane Hoppe-Jones, Samir Al-Mashharawi, Moustapha Harb, Mohanned Al-ghamdi, Nizar Jaber, Noor Zaouri, Sheng Li and Abdullah Al-shahri for lab support.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0043135417303731
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC)

Full metadata record

DC FieldValue Language
dc.contributor.authorDehwah, Abdullahen
dc.contributor.authorMissimer, Thomas M.en
dc.date.accessioned2017-05-22T06:58:04Z-
dc.date.available2017-05-22T06:58:04Z-
dc.date.issued2017-05-11en
dc.identifier.citationDehwah AHA, Missimer TM (2017) Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment. Water Research 121: 95–108. Available: http://dx.doi.org/10.1016/j.watres.2017.05.014.en
dc.identifier.issn0043-1354en
dc.identifier.doi10.1016/j.watres.2017.05.014en
dc.identifier.urihttp://hdl.handle.net/10754/623684-
dc.description.abstractSeabed gallery intake systems used for seawater reverse osmosis facilities employ the same principle of water treatment as slow sand filtration in freshwater systems. An investigation concerning the effectiveness of the active layer (top layer) in improving raw water quality was conducted by using a long-term bench-scale columns experiment. Two different media types, silica and carbonate sand, were tested in 1 m columns to evaluate the effectiveness of media type in terms of algae, bacteria, Natural Organic Matter (NOM) and Transparent Exopolymer Particles (TEP) removal over a period of 620 days. Nearly all algae in the silica sand column, 87% (σ = 0.04) of the bacteria, 59% (σ = 0.11) of the biopolymer fraction of NOM, 59% (σ = 0.16) of particulate and 32% (σ = 0.25) of colloidal TEP were removed during the last 330 days of the experiment. Total removal was observed in the carbonate sand column for algal concentration, while the bacterial removal was lower at 74% (σ = 0.08). Removal of biopolymers, particulate and colloidal TEP were higher in the carbonate column during the last 330 days with 72% (σ = 0.15), 66% (σ = 0.08) and 36% (σ = 0.12) removed for these organics respectively. Removal of these key organics through the 1 m thick column, representing the active layer, will likely reduce the rate of biofouling, reduce chemical usage and minimize operating cost in SWRO systems. The data show that the media will require several months at the beginning of operation to reach equilibrium so that high organic removal rates can be achieved. No development of a “schmutzdecke” layer occurred. The experimental results suggest that unlike freshwater slow sand filtration wherein most water treatment occurs in the upper 10 cm, in seawater systems treatment occurs throughout the full active layer depth of 1 m. The results of this study will help in designing and operating seabed gallery intake systems in varied geological conditions.en
dc.description.sponsorshipFunding for this research was provided by King Abdullah University of Science and Technology, Thuwal, Saudi Arabia. The authors thank the Water Desalination and Reuse Center for the use of analytical equipment. Thanks are also extended to Ulrich Buttner for helping in designing the columns and Christiane Hoppe-Jones, Samir Al-Mashharawi, Moustapha Harb, Mohanned Al-ghamdi, Nizar Jaber, Noor Zaouri, Sheng Li and Abdullah Al-shahri for lab support.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0043135417303731en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Water Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Water Research, 10 May 2017. DOI: 10.1016/j.watres.2017.05.014. © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectSeawater reverse osmosisen
dc.subjectMembrane fouling/biofoulingen
dc.subjectGallery intakesen
dc.subjectSlow sand filtrationen
dc.subjectNatural organic matteren
dc.titleSeabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experimenten
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalWater Researchen
dc.eprint.versionPost-printen
dc.contributor.institutionU. A. Whitaker College of Engineering, Florida Gulf Coast University, 10501 FGCU Boulevard South, Fort Myers, FL, 33965-6565, United Statesen
kaust.authorDehwah, Abdullahen
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