Seawater Desalination Plants
for Coastal, Island, and Remote Sites.
When a project site has coastline but no freshwater infrastructure, desalination often becomes the most reliable supply route — the engineering question is how to engineer a system that holds up under variable salinity, limited power, restricted access, and brine disposal constraints. We confirm source TDS, intake type, SDI risk, high-pressure pump class, ERD economics, product water standard, storage reserve, and brine disposal before specifying seawater desalination plants matched to your site constraints.
*available on request for applicable pressure vessel components
Seawater Desalination Plants for Resort, Community, or Industrial Site — Find Your Configuration.
Three pre-engineered seawater desalination plant configurations matched to site type and output application. Find the description that fits your project — then request the full specification from our engineering team.
Island hotel, coastal resort, or remote accommodation
Self-contained supply · Peak occupancy buffer · 150–500 m³/day
- Running a coastal resort, island hotel, or remote lodge where water barge delivery is unreliable or prohibitively expensive during peak occupancy
- Need consistent product water at 150–300 ppm TDS with pH stabilisation and remineralisation — guest-facing water quality and plumbing protection
- Freshwater supply reliability directly affects occupancy, guest experience, and operational continuity
Seawater intake → Pretreatment → SWRO membrane + ERD → pH and mineral conditioning → Buffer storage → Property distribution
After you submit — an engineer reviews within 24–48 h. No complete water analysis required to start; send available data and we will identify what is still needed before final sizing.
Remote community or island drinking water supply
WHO / national standard · Potable distribution · Community scale
- Island or coastal community currently dependent on rainfall collection, trucked water, or unreliable seasonal surface supply
- Need WHO-compliant or national standard drinking water at reliable daily output volume — UV sterilisation, chlorination, and remineralisation required
- The system must operate with local operators; training, remote monitoring, and consumable supply planning are part of the project scope
Seawater intake → Pretreatment → SWRO + ERD → Post-treatment to WHO potable standard → Community storage → Distribution
After you submit — an engineer reviews within 24–48 h. No complete water analysis required to start; send available data and we will identify what is still needed before final sizing.
Containerized desalination plant for coastal industry or offshore platform
500+ m³/day · Process water · ASME pressure rated · Modular expansion
- Power generation, aquaculture, food processing, or offshore platform requiring freshwater from a seawater source at volumes municipal supply cannot guarantee
- Process water quality may require TDS below 50 ppm after polishing — boiler feed, cooling makeup, or ingredient water beyond standard SWRO permeate
- Site is remote or offshore; containerized format, ASME-rated pressure components, and expansion headroom are engineering requirements from the outset
Seawater intake → Enhanced pretreatment → SWRO + ERD → Post-treatment to process specification → Product storage → Process circuits
After you submit — an engineer reviews within 24–48 h. No complete water analysis required to start; send available data and we will identify what is still needed before final sizing.
Not sure which scenario fits? Describe your site, source water, and daily demand below — our engineers will confirm the right configuration and respond with a site-specific proposal.
From seawater intake to product water — the complete seawater desalination plants treatment route.
A correctly engineered seawater desalination system is a treatment train where each stage conditions the water for the next. Every stage has a defined output quality and a defined failure mode — skipping or undersizing any stage affects product quality, membrane life, or regulatory compliance.
| Stage | Key Operating Parameter | Engineering Consequence if Undersized / Omitted |
|---|---|---|
| Pretreatment (multimedia + cartridge) | Typically designed to achieve SDI below 3 at the SWRO membrane inlet — reliably and within the selected membrane manufacturer’s maximum feed SDI limit. Coagulation and 5 µm cartridge filtration mandatory; DAF added where algal bloom or high turbidity risk exists. | SDI above the membrane manufacturer’s maximum inlet limit accelerates particulate fouling on feed spacers; CIP intervals compress and membrane life shortens materially below design expectation. |
| High-pressure pump + ERD | SWRO operating pressure 800–1,000 psi (55–69 bar); pump, vessel, and piping rated for SWRO pressure class. Pressure exchanger ERD transfers ~90% of hydraulic energy from brine back to feed stream — industry reference: ~3–4 kWh/m³ with ERD versus ~8–10 kWh/m³ without. | Oversizing the pump without ERD compounds operating cost on diesel-powered remote sites; undersized ERD negates the energy savings that make off-grid SWRO economically viable. |
| SWRO membrane array | SWRO elements rated for full-strength seawater TDS 33,000–45,000 ppm; salt rejection typically 99.5–99.8% under design conditions; product TDS 150–500 ppm before post-treatment. Staging, elements per vessel, and recovery set by source TDS and product demand. See our seawater desalination systems for membrane specifications. | Specifying BWRO elements for seawater-strength feed causes rapid salt rejection decline and produces product TDS far above potable or process specification within the first operating year. |
| Post-treatment train | Raw SWRO permeate is low in minerals, has suppressed pH from dissolved CO₂ permeation, and is aggressive to unprotected pipework. Potable: pH adjustment, calcite or limestone remineralisation, UV disinfection, and chlorination to WHO or national standard. Boron control evaluated where strict limits apply. | Untreated SWRO permeate distributed without pH and mineral correction corrodes pipe fittings, fails WHO conductivity or corrosivity limits, and leaves distribution infrastructure exposed to accelerated degradation. |
| Product water storage | Minimum 30 minutes peak building or community demand as buffer volume. SWRO produces at a continuous rate; storage absorbs demand peaks without cycling the high-pressure pump. Sized with two-day operating reserve as common basis for remote and isolated sites. | Undersized storage forces the treatment plant to match instantaneous peak demand — high-pressure pump short-cycling reduces seal and bearing service life; membrane flux variation accelerates fouling. |
Our seawater desalination systems are configured to your source TDS, intake type, recovery target, and brine disposal constraints — not to a standard product table. Whether the application is a large salt water desalination plant serving a coastal community or a containerized SWRO unit deployed to a single-facility island site, the engineering process starts from tested feed water quality and documented site operating constraints.
SWRO or BWRO — how the routing decision is made
Not every elevated-salinity source requires SWRO. The routing decision turns on measured source TDS and seasonal variation. A coastal groundwater aquifer consistently below 8,000 ppm TDS with no confirmed seasonal surge is a brackish water RO systems application — lower pressure, lower energy, lower capital. Any source confirmed above 10,000 ppm, or a boundary case where dry-season readings may exceed 10,000 ppm, must be engineered as SWRO from the outset. Specifying BWRO into seawater-strength feed is the most common planning error in coastal projects.
Container format and capacity — preliminary planning reference
A 20ft ISO container format typically accommodates 100–500 m³/day; a 40ft unit scales to approximately 500–2,500+ m³/day. These are preliminary planning ranges for initial project evaluation only. Final container format depends on pretreatment depth, recovery, ERD configuration, post-treatment, chemical storage, maintenance clearance, and site climate control requirements. Modular parallel units allow capacity expansion without decommissioning the operating train — intake, manifold, electrical capacity, storage, and brine outfall should be sized for the expansion target from Phase 1.
Engineering variables reference.
Every SWRO system design starts with site-specific data. The ranges below are industry references for engineering context, not guaranteed values. Actual design parameters are confirmed through project review against tested source water, power, brine disposal, and application data.
| Parameter | Typical Range | Engineering Consequence | Configuration Approach |
|---|---|---|---|
| Source water TDS | 33,000–45,000 ppm (open seawater); coastal wells vary by intrusion depth | Determines operating pressure, membrane element selection, and product TDS before post-treatment; seasonal variation of ±2,000–5,000 ppm affects pressure planning. | Measured at site with seasonal cycle documented; design pressure and membrane selection confirmed from worst-case TDS, not annual average. |
| Operating pressure | 800–1,000 psi (55–69 bar) | Pump, pressure vessel, piping, and seals must be rated for SWRO pressure class — far above BWRO’s 150–600 psi range; ASME-rated components where project specification requires. | Pump and pressure vessel selection confirmed from source TDS, temperature, and recovery target; pressure class verified at design stage. |
| Recovery rate | 35–45% | SWRO recovery limited by osmotic pressure; higher recovery compresses brine TDS and increases HP pump load; brine volume at 40% recovery equals 60% of feed flow. | Recovery target set after reviewing source TDS, brine disposal constraints, product demand, and energy budget. |
| Pretreatment SDI target | SDI below 3 at SWRO membrane inlet — typical design target; confirmed against selected membrane manufacturer’s maximum feed SDI limit | SDI above the membrane manufacturer’s maximum inlet limit accelerates fouling and compresses CIP intervals; pretreatment must achieve SDI below 3 reliably across seasonal source variation. | Beach well reduces SDI load where geology permits, but SDI, iron, manganese, sulfide, and microbiology must still be confirmed by site testing. Open sea intakes require coagulation, DAF where algal risk, multimedia filtration, and 5 µm cartridge. |
| Energy with ERD | Approx. 3–4 kWh/m³ under design conditions — typical design reference, not a guaranteed site value; actual energy depends on feed TDS, recovery, pump efficiency, temperature, and ERD model | Without ERD, industry reference figures are roughly 8–10 kWh/m³; at a remote diesel site this difference controls generator sizing, fuel logistics, and operating economics. | Pressure exchanger ERD selected from flow rate, recovery, and energy target; ERD integration confirmed at design stage before pump and generator sizing is finalised. |
| Container format capacity | 20ft: 100–500 m³/day; 40ft: 500–2,500+ m³/day — preliminary planning ranges only | Under-specified container capacity means peak demand is not met or parallel units must be added earlier than planned; expansion headroom should be confirmed at Phase 1 design. | Final format depends on pretreatment depth, recovery, ERD, post-treatment, chemical storage, maintenance access, and site climate control; ranges used for initial project scoping only. |
| Post-treatment standard | Application-dependent: WHO / national potable, industrial process, aquaculture species specification | Raw SWRO permeate at 150–500 ppm TDS is low in minerals, has suppressed pH, and is aggressive to unprotected distribution pipework — post-treatment is mandatory for potable and most industrial use. | pH adjustment, calcite or limestone remineralisation, UV disinfection, and chlorination for potable; EDI or mixed bed polishing for boiler feed; species-specific conditioning for aquaculture. |
| Brine concentration and disposal | 55–65% of feed volume; approx. 2× feed TDS | At 40% recovery from 35,000 ppm feed, brine is approximately 65,000 ppm at 60% of feed flow; brine disposal pathway must be resolved before plant configuration is finalised. | Final disposal route confirmed by local environmental permitting, hydrodynamic modelling, receiving-water sensitivity, diffuser design, and monitoring. Sensitive habitats — coral reefs, seagrass, mangroves, shellfish areas, marine protected zones — must be identified before finalising outfall route. |
| LSI / alkalinity / corrosion control | Target LSI or CCPP slightly positive for distribution stability; alkalinity added with pH adjustment | Low-mineral SWRO permeate is aggressive to unprotected cement-lined pipe, mild steel, and galvanised fittings in distribution networks. | Calcite contactor, CO₂ addition, or NaOH with remineralisation; corrosion inhibitor only where permitted by local drinking water regulation. |
| Boron / borate | Measured in full seawater analysis; limit confirmed by WHO guideline (2.4 mg/L) or local drinking water regulation | Single-pass SWRO may not reliably meet strict boron limits — boric acid is weakly ionised at neutral pH and passes membrane more readily than fully ionised anions. | Evaluate pH adjustment, second-pass RO, boron-selective resin, blending strategy, or local regulatory acceptance during design review. |
Engineering credentials & export capability.
Founded in 2016, Qingdao Hiju Thermal Power Co., Ltd operates from a 70,500 sqm facility with 21,000 sqm of dedicated production workshop space. Our engineering team comprises 78 technicians and 28 engineers structured to handle full project scope — from design review through factory testing to export documentation.
We hold CE, ISO 9001 and ASME-related manufacturing documentation for applicable pressure-rated components. For SWRO applications where project specifications require pressure-vessel documentation at high operating pressure, ASME-compliant components can be supplied on request. CE and ISO 9001 are standard compliance documentation for seawater desalination export projects — reviewed at tender stage across Southeast Asia, the Middle East, Africa, South America, and Central Asia.
Our systems have been exported to clients in more than 20 countries and regions, with primary markets in Southeast Asia, the Middle East, Africa, South America and Central Asia. Review our completed engineering projects to verify project type, application and export geography without relying on marketing claims, or browse our full range of industrial water treatment plant solutions by application sector.
Submit your water treatment requirements.
Getting the right system specification requires site-specific data that cannot be substituted by nominal capacity estimates or regional averages. Send the inputs below — our engineering team confirms intake type, pretreatment scope, pump class, ERD selection, and post-treatment configuration as a project memo.
Source water & output inputs
- Source water quality — Measured TDS at intake, with seasonal variation if available. Full analysis: hardness, alkalinity, sulfate, chloride, silica, SDI or turbidity, pH, boron, and temperature.
- Intake type — Open sea, beach well, tidal estuary, enclosed bay, or other. Distance and elevation from intake to plant location.
- Required daily production — m³/day or GPD; peak vs. average demand and operating hours per day.
- Output standard — Potable (WHO, national standard), industrial process specification, aquaculture species target, or other.
- Brine disposal — Coastal outfall, deep well injection, evaporation pond land area, or ZLD requirement.
Site & project inputs
- Location — Country, coastal or island setting, coordinates or nearest port; any environmental or permitting constraints known.
- Power supply — Grid, diesel generator, solar PV, or hybrid. Available amperage and any fuel delivery frequency constraint.
- Installation space — Available footprint for container, storage tank, and intake piping; building or open site.
- Expansion plan — Expected modular expansion beyond the initial installation; target capacity for Phase 2 or 3.
- Project scope — Required delivery date; OEM, ODM, or white-label requirement; certification needs for procurement or local approval.
For rapid dialogue in Southeast Asia, the Middle East, Africa, or South America, contact our engineering team via WhatsApp or email with your source water analysis and site power data.
For coastal communities and island settlements where the output requirement is WHO-compliant drinking water for distribution to households, our municipal and community drinking water solutions cover the compliance documentation, distribution design, and monitoring framework for regulated community supply projects. water filtration system for drinking
For coastal aquaculture facilities and irrigated agricultural sites where SWRO product water is used as the makeup source for fish tanks, shrimp ponds, or irrigation circuits, our aquaculture and irrigation water treatment solutions address the species-specific TDS, ion balance, and pathogen control requirements downstream of the desalination system. agriculture water filtration
Explore by product category
Every piece of equipment used in the configurations above belongs to one of these six product families. Browse the full range, specifications, and configuration options.