Shuqaiq-II IWP is a combined RO water desalination and power plant facility. It operates
with an open intake that feeds the plant with 100,000 m3/h of raw water. The facility is
located 140 km north of Jizan, in a small bay where the run-off discharges of two wadis
converge. The run-off coming from the wadis are rich in alluvial sediments that
dramatically decrease the raw water quality at the intake point, causing periodic
shutdowns of the plant and increasing the operational cost due to membrane replacement.
Subsurface water intakes are an alternative for improving raw water quality, as they
provide natural filtering of the feed water as it flows through the systems. In this type of
system water flow through the sediment matrix is induced and during the percolation,
several physical, chemical and biological processes take place, cleaning the water from
particulate matter, resulting in high quality feed water that can be directly sent to the RO
process without any additional pretreatment.
A full hydrogeological profile of the seabed needs to be performed in order to determine
the applicability of one of these systems in each particular location. In this study, 1 km of
beach area at Shuqaiq-II IWP was surveyed. Ninety-one (91) samples from the shore and offshore sediments were collected and analyzed for hydraulic conductivity, porosity and
grain size distribution.
The laboratory analysis showed that the construction of the seabed galleries was
technically feasible, and the proposed intake system was design to meet the feed water
requirements for the RO facility (530.000 m3/d). The preliminary design consists of 17
cells in total, 16 of which will be in constant operation, and 1 alternate for whenever
maintenance is needed in one of the other cells. The seabed gallery design includes 5
layers of sands with a total depth of 5 m. A detailed underdrain design methodology is
presented. The system would be operated at an infiltration rate of 10 m/d and an average
hydraulic retention time of 7h. Each cell will have an area of 3.500 m2 that will supply
35.000 m3/d of feed water to each RO train.
Date of Award | Apr 2013 |
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Original language | English (US) |
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Awarding Institution | - Biological, Environmental Sciences and Engineering
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Supervisor | Thomas Missimer (Supervisor) |
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- SWRO pre-treatment
- sea bed gallery
- slow sand filteration (SSF)
- desalination
- water intake
- infiltration galleries