The ability to economically desalinate seawater in arid regions of the
world has become a vital advancement to overcome the problem on
freshwater availability, quality, and reliability. In contrast with the major capital
and operational costs for desalination plants represented by conventional
open ocean intakes, subsurface intakes allow the extraction of high quality
feed water at minimum costs and reduced environmental impact. A seabed
filter is a subsurface intake that consists of a submerged slow sand filter, with
benefits of organic matter removal and pathogens, and low operational cost.
A site investigation was carried out through the southern coast of the
Red Sea in Saudi Arabia, from King Abdullah University of Science and
Technology down to 370 kilometers south of Jeddah. A site adjacent to the
Shoaiba desalination plant was selected to assess the viability of constructing
a seabed filter. Grain sieve size analysis, porosity and hydraulic conductivity
permeameter measurements were performed on the collected sediment
samples. Based on these results, it was concluded that the characteristics at
the Shoaiba site allow for the construction of a seabed filtration system.
A seabed filter design is proposed for the 150,000 m3/d Shoaiba III
expansion project, a large-scale Reverse Osmosis desalination plant. A filter
design with a filtration rate of 7 m/d through an area of 6,000 m2 is proposed to meet the demand of one of the ten desalination trains operating at the
plant. The filter would be located 90 meters offshore where hydraulic
conductivity of the sediment is high, and mud percentage is minimal. The thin
native marine sediment layer is insufficient to provide enough water filtration,
and consequently the proposed solution involves excavating the limestone
rock and filling it with different layers of non-native sand and gravel of
increasing grain size.
An initial assessment of the area around Shoaiba showed similar
sedimentological conditions that could lead into the application of comparable
seabed filter design concepts to supply the entire feed water requirement of
the plant. Considerations for the construction of a seabed filter should include
technical feasibility and life cycle assessment, i.e. capital costs, operating
costs and environmental impacts.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/234971 |
| Date | 06 1900 |
| Creators | Rodríguez, Luis Raúl |
| Contributors | Missimer, Thomas M., Biological and Environmental Sciences and Engineering (BESE) Division, Amy, Gary L. |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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