EVERY DROP COUNTS. Desalination plants help ensure water security in drought-prone and arid areas, supporting communities, agriculture, and economic development.
¹Source: International Desalination and Reuse Association (IDRA), Desalination and Reuse Handbook 2023
²Source: Discovery: The Largest Desalination Plants in the World
- Corrosion of concrete reinforcement due to chloride attack: Chlorides from salt can penetrate concrete and cause corrosion of the embedded steel reinforcement. When chlorides reach the steel, they break down its protective layer, causing rust. The rust expands, creating internal pressure that leads to concrete cracking, spalling, and structural damage.
- Sulphate attack: Sulphates react with calcium hydroxide and tricalcium aluminate (a component of cement) in the concrete and form expansive compounds like ettringite and gypsum, which can cause the concrete to crack and deteriorate.
- Leaching of calcium compounds: Seawater can cause leaching of calcium hydroxide from the cement matrix. This leaching weakens the concrete structure by reducing its density and strength, making it more porous and susceptible to further chemical attacks.
- Soft water: After salt extraction, soft water becomes slightly acidic and has high dissolving capacity, which can potentially harm concrete and metallic elements.
- Other attacks: These include carbonation, magnesium attack, freeze-thaw cycles (in cold climates), abrasion, etc.
1. Seawater Intake
Large pipes that extend into the sea to collect water are the most commonly used method.
Screens and filters remove large debris and marine life to prevent damage to the plant's equipment.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
2. Pretreatment
Prepares the seawater for the desalination process by removing suspended solids and microorganisms.
- Coagulation and flocculation tanks: Chemicals are added to coagulate and aggregate suspended particles.
- Sedimentation tanks: Allow larger particles to settle out.
- Filtration units: Often include multiple media filters (sand, gravel) and cartridge filters to remove finer particles.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
3. Reverse Osmosis
Reverse osmosis (RO) removes dissolved salts and minerals from seawater using semi-permeable membranes under high pressure.
This process separates the water into two streams: purified water with a very low salt concentration and highly concentrated saline byproduct called brine.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
Liquid-applied floors
4. Brine Discharge
Manages the discharge of the concentrated brine (high-salt byproduct) back into the sea.
- Discharge pipes: Transport the brine to a designated discharge point.
- Diffusers: Spread the brine over a larger area to minimize environmental impact.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
5. Post Treatment
Ensures the desalinated water meets quality standards for consumption.
- Re-mineralisation: Adds essential minerals (such as calcium and magnesium) to the water to improve taste and ensure it meets health standards.
- pH adjustment: Balances the pH of the water, often using lime or carbon dioxide.
- Disinfection: Uses chlorine or ultraviolet light to eliminate any remaining microorganisms.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
6. Storage & Distribution
Delivers the treated water to storage or directly to consumers.
- Pumping stations: Move the water from the plant to distribution networks.
- Pipelines: Transport the water to storage facilities or the distribution network.
- Storage tanks.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Waterproofing mortars
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
7. Plant Buildings
Desalination plants are industrial plants with large amounts of technical rooms supporting the main desalination process and ensuring the smooth operation of the facility. These can house equipment, systems, and components that provide essential utilities, storage, and maintenance functions. There are also office and control buildings, which serve as hubs for administrative tasks, operational monitoring, and control system management to ensure efficient plant performance.
Enabling sulphate, chloride and abrasion-resistant concrete
Sulphate-resistant repair mortars approved for seawater contact
Reactive coating (different products according to the areas where the plant is located)
Liquid-applied polyurea (PUA) membranes
Waterbars
Hydrophilic gaskets
Joint sealant
Joint and crack sealing system
Industrial flooring systems
Systems Plus Knowhow: Sika's Holistic Approach to Water Infrastructure
Sika empowers water infrastructure owners, architects, engineers, operators, and contractors with comprehensive support, ensuring project success.
Our commitment extends beyond providing high-quality products; we offer:
Expert Guidance
- In-depth technical advice and assistance throughout the project lifecycle.
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Cost-Effective Solutions
- Sika's expertise minimies overall project costs by optimising performance and extending service life.
Comprehensive Product Portfolio
Sika delivers a complete range of durable and reliable solutions specifically engineered for demanding water infrastructure applications, including:
- Concrete admixtures
- Waterproofing membranes
- Concrete protection coatings
- Watertight joint systems
- Concrete repair and reinforcement systems
