Pressurized multi-media filtration for desalination the clarification of seawater

1. Seaclean™
Filter
PRESSURIZED MULTI-MEDIA FILTRATION FOR DESALINATION
THE CLARIFICATION OF SEAWATER
PROTECT THE CORE OF REVERSE
OSMOSIS MEMBRANES WITH MULTI-
P-PPT-D-003-EN-1004
MEDIA FILTRATION

2. DESALINATION
DESSALEMENT
CONTENTS
Seaclean™
Filter
Seawater Pre-treatment Objectives
Seaclean™ Filter Description
Seaclean™ Filter in Treatment Lines
Product Performances
Advantages of Seaclean™ Filter
Case Study: Al Dur, Bahrain
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3. DESALINATION
DESSALEMENT
PRE-TREATEMENT OBJECTIVES
Seaclean™
Filter
To maximize the efficiency and lifespan of a
desalination plant using reverse osmosis,
pretreatment aims to prevent clogging of
osmosis membranes by:
• removing algae/suspended solids/colloids,
• obtaining a low clog power of water.
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4. DESALINATION
DESSALEMENT
Seaclean™ Filter DESCRIPTION (1/2)
Seaclean™
Filter • Seaclean™ Filter is a pressurized horizontal filter that
applies a downflow through 2 layers of media:
− A top layer of anthracite
– A bottom layer of sand
• The characteristics of Seaclean™ Filter:
– Diameter 4m
– Length 12,5 or 16 m
– Nominal surface area: 51 m² or 63m²
• Backwash is divided in 2 phases:
– One air phase
– One water phase
ANTHRACITE
SAND
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5. DESALINATION
DESSALEMENT
Seaclean™ Filter DESCRIPTION (2/2)
Seaclean™ • The innovation consists in applying the new Anthracite / Sand
Filter
pair while the pressurized twin-layer technique remains
unchanged.
• The first layer is used to screen out suspended solids.
• The second layer is used to reduce the SDI (Silt Density Index)
• There are 2 possible media combinations:
– Type A combination: Anthracite = 1.5mm / Sand = 0.28mm
– Type B combination: Anthracite = 1.2mm / Sand = 0.28mm
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6. DESALINATION
DESSALEMENT
Seaclean™ Filter IN TREATMENT LINES
Seaclean™ Seaclean™ Filter forms part of Reverse Osmosis pre-treatment
Filter
in seawater desalination line.
• Downstream from a flash flotation tank (Seadaf™) on water that has
occasional organic matter and algae bloom peaks:
Coagulant
Coagulant
H2SO4
H2SO4
Coag. aid
RO
Seaclean™
Seadaf™
• In direct filtration application for treating turbidity:
Coagulant
H2SO4
Coag. aid
RO
Seaclean™
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7. DESALINATION
DESSALEMENT
Seaclean™ PERFORMANCE (1/2)
Seaclean™ • FILTRATION VELOCITIES:
Filter
− Depending on the quality and temperature of the water
− Depending on whether or not the clarification stage is
included (flotation or sedimentation)
FILTRATION VELOCITY ON DUAL MEDIA FILTER
* Velocity n : nominal velocity range with all the filters in operation
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8. DESALINATION
DESSALEMENT
Seaclean™ PERFORMANCE (2/2)
Seaclean™ • BACKWASH VELOCITIES:
Filter
Backwash velocity during water alone phase at 20°C for media combinations.
(NES = Nominal Effective Size in mm)
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9. Seaclean™ Filter ADVANTAGES
DESALINATION
DESSALEMENT
Seaclean™
Filter
• FILTERED WATER OF A STABLE QUALITY:
– Good layer re-grading after washing
– Regular cycle times
• MINIMIZED DANGER OF MEDIA LOSS:
– Thanks to the optimized process
(filtration / backwash rate)
• WASH EQUIPMENT REDUCED TO A MINIMUM
• EFFICIENT REVERSE OSMOSIS PRE-TREATMENT
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10. CASE STUDY:
AL DUR, BAHRAIN
CONTEXT:
• Client: Hyundai Heavy Industries (GDF Suez
Energy Int. / Gulf Investment Corporation 50/50
consortium)
• Contract: BOO – Commissioning: 2011
• Electricity generating and seawater
desalination plant
DESIGN:
• Drinking water production capacity:
218,000 m3/jour
• Treatment line:
− Pumping
− 14 Seadaf™ flotation units
− 44 Seaclean™ units
− 26 reverse osmosis racks, 1st pass
− Energy recovery (Pelton Turbine)
− 12 reverse osmosis racks, 2nd pass
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