High-Efficiency Desalination & Industrial Process Solutions
Explore our field-proven reverse osmosis, purified water, and volume reduction systems engineered for global industrial and municipal deployments.
Overcoming Global Water Stress Through Advanced Desalination Engineering
A rigorous examination of energy flux reduction, isobaric energy recovery, and high-recovery membrane dynamics in modern SWRO plant architectures.
Isobaric Energy Recovery (ERD)
Modern SWRO demands low specific energy consumption (SEC). By integrating ceramic isobaric pressure exchangers (PX) and positive displacement turbochargers, Tongjie plants recycle hydraulic energy from the concentrated reject brine stream back into the high-pressure feed, reducing net power consumption from legacy 8.0 kWh/m³ down to ≤ 2.8–3.2 kWh/m³.
- Up to 98% energy transfer efficiency
- Minimizes OPEX for remote microgrid operation
Pretreatment & Biofouling Control
Feedwater variations across open ocean and coastal intakes expose reverse osmosis membranes to seasonal algal blooms (red tides) and particulate fouling. Tongjie engineers automated dual-media filtration (sand-anthracite) coupled with hollow-fiber ultrafiltration (UF) polishing to sustain a Silt Density Index (SDI15) consistently under 2.5.
- Continuous oxidation-reduction potential (ORP) tracking
- Automated CIP & chemically enhanced backwash (CEB)
Metallurgical Integrity in Harsh Brine
Handling 35,000 to 45,000 mg/L TDS seawater under 60–75 bar pressures causes rapid pitting in conventional stainless steel. Tongjie exclusively utilizes Super Duplex Stainless Steel (2507 / UNS S32750) and 2205 Duplex for high-pressure wetted headers, paired with non-metallic high-pressure FRP membrane vessels rated to 1200 PSI.
- PREN (Pitting Resistance Equivalent Number) > 42
- ASME B31.3 piping compliance with full radiographic testing
CE Certification Rigor: PED, Machinery & Electrical Directives
Navigating the stringent technical compliance landscape required by European Union authorities, EPC contractors, and global engineering inspection agencies.
The Anatomy of CE Conformity for Desalination Plants
For international buyers and European utility developers, CE certification is not simply a decorative sticker; it represents full legal and technical verification across key European Directives:
- Pressure Equipment Directive (PED 2014/68/EU): Covers high-pressure membrane housings, cartridge filter vessels, pulse dampeners, and manifold piping operating at pressures up to 83 bar. Every vessel holds third-party hydrostatic pressure testing certifications and material traceability heat numbers.
- Machinery Directive (2006/42/EC): Rigorous evaluation of moving parts, high-pressure plunger pumps, booster assemblies, and automatic valve actuators. Includes comprehensive HAZOP (Hazard and Operability Analysis) and safety interlock architectures.
- Low Voltage (2014/35/EU) & EMC (2014/30/EU): Fully compliant PLC panels (Siemens S7-1500 / Allen-Bradley ControlLogix) with CE-rated VFD drives, isolated signal conditioning, and surge suppressors tested against industrial electromagnetic interference.
Factory Acceptance Testing (FAT) & Quality Dossier
Tongjie mitigates project delivery risks through exhaustive pre-commissioning at our Shanghai manufacturing campus before container loading and international dispatch:
- Full Hydraulic & Electrical Load Testing: Systems undergo complete pressurized wet testing using simulated salinity feedwater to evaluate pump harmonics, PX energy transfer, and membrane flux dynamics.
- NDT & Weld Quality Verifications: Duplex and Super Duplex high-pressure piping assemblies undergo dye penetrant inspection (DPI) and radiographic examination (RT) according to ASME Section IX standards.
- Comprehensive Technical Construction File (TCF): Every unit is shipped with full P&IDs, electrical schematics, CE Declaration of Conformity, calibration records, and bilingual maintenance manuals.
Regional Demands & Engineering Tailoring Across Global Basins
How feedwater salinities, thermal fluctuations, and local regulatory protocols dictate process engineering across major maritime and industrial zones.
Middle East & GCC Basins
Conditions: Arabian Gulf and Red Sea TDS levels reach 42,000–48,000 mg/L with water temperatures exceeding 38°C. High salinity and heat reduce osmotic driving forces and elevate scaling risks.
Solution: High-pressure pumps rated to 80+ bar, specialized seawater RO membranes with high boron rejection (>93% at pH 8), and pre-cooling heat exchange modules.
Mediterranean & Southern Europe
Conditions: Moderate TDS (37,000–39,000 mg/L) combined with strict EU environmental directives restricting chemical backwash discharge and acoustic emissions near coastal tourism centers.
Solution: Sound-attenuated container enclosures (< 72 dBA at 1 meter), low-chemical or chemical-free UF backwash protocols, and CE-certified ultra-low energy recovery devices.
Southeast Asia & Pacific Rim
Conditions: Remote island archipelagos, eco-resorts, and naval stations with unstable electrical grids, high humidity, and monsoon-driven turbid runoff carrying heavy suspended solids.
Solution: Integrated containerized SWRO coupled with hybrid off-grid photovoltaic/diesel microgrids. Self-cleaning coagulant dosing skids and rugged sand-bed filtration.
Americas & Australian Mining
Conditions: Coastal processing hubs, lithium extraction, and remote copper mining requiring freshwater for ore washing, dust suppression, and high-purity boiler feedwater.
Solution: Modular container trains with integrated second-pass brackish RO, mixed-bed EDI polishing, and containerized SCADA systems linked to central mining operations via satellite.
Engineering Comparison: Membrane Architecture & System Topologies
Evaluate how containerized SWRO compares across capital cost, installation velocity, footprint, and operational energy against alternative water treatment models.
| Plant Topology | Feed Salinity Range | Target Recovery Rate | Specific Energy (SEC) | Civil Infrastructure Required | Commissioning Timeline |
|---|---|---|---|---|---|
| Containerized SWRO (Tongjie ISO Series) | 32,000 – 45,000 mg/L TDS | 40% – 48% | 2.8 – 3.2 kWh/m³ | Minimal (Flat reinforced slab only) | 5 – 10 Days (Plug-and-Play) |
| Permanent Civil SWRO Facility | 32,000 – 45,000 mg/L TDS | 45% – 50% | 3.0 – 3.6 kWh/m³ | Extensive concrete, deep intake piping | 12 – 24 Months |
| Disc Tube Reverse Osmosis (DTRO Skid) | 40,000 – 120,000 mg/L TDS | 65% – 85% | 6.5 – 11.0 kWh/m³ | Skid foundation / Sheltered pad | 15 – 20 Days |
| Thermal Distillation (MED / MSF) | 35,000 – 60,000 mg/L TDS | 25% – 35% | 12.0 – 18.0 kWh-eq/m³ | Heavy industrial boiler / turbine interface | 18 – 36 Months |
| Two-Pass Industrial RO + EDI Skid | 500 – 3,000 mg/L TDS | 75% – 85% | 1.2 – 1.8 kWh/m³ | Indoor cleanroom / utility floor | 7 – 14 Days |
Tailored Engineering for Mission-Critical Water Production
Real-world integration scenarios demonstrating how our CE-certified manufacturing framework solves extreme water treatment and environmental compliance challenges.
Island & Coastal Municipality Supply
Remote communities face seasonal population spikes from tourism and severe dry seasons. Tongjie containerized SWRO units arrive with built-in air conditioning, lighting, and internal piping.
- Produces WHO-standard potable water (< 200 mg/L TDS)
- Automated calcite remineralization & sodium hypochlorite disinfection
Oilfield Produced Water & Frac Flowback
Unconventional shale extraction generates millions of liters of hypersaline flowback fluid laden with heavy hydrocarbons, barium, and suspended solids. Tongjie combines hydrocyclone de-oiling, chemical softening, and Disc Tube Reverse Osmosis (DTRO).
- Effluent oil content reduced to ≤ 5 mg/L
- Suspended solids ≤ 1 mg/L for subsurface reinjection compliance
Semiconductor & Pharma Ultrapure Feed
Before water can be polished into 18.2 MΩ·cm ultrapure water (UPW) or Water for Injection (WFI), high-salinity feed water must be stripped of divalent salts, silica, and TOC.
- Double-pass RO coupled with continuous Electro-deionization (EDI)
- Complete audit trail data logging meeting 21 CFR Part 11 requirements
Next-Generation Technology Roadmap & AI Autonomous Plant Operation
Pioneering the convergence of digital twins, artificial intelligence, and biomimetic membrane membranes to achieve true zero-footprint water processing.
AI Predictive Membrane Fouling & Digital Twins
By capturing thousands of high-frequency sensor readings (trans-membrane pressure, differential pressure across stages, conductivity decay, and temperature), Tongjie's proprietary neural models anticipate organic and colloidal fouling 72 to 120 hours before flux degradation occurs.
- Automated dynamic anti-scalant dosing calibration
- Extends operational membrane life by 25–35%
Green Hydrogen Electrolyzer Coupling
Green hydrogen plants require ultra-pure, demineralized water (approx. 9 liters of high-purity water per kilogram of H2). Tongjie is deploying containerized SWRO units directly integrated with PEM and alkaline electrolyzer balance-of-plant (BOP) systems in coastal offshore wind hubs.
- Conductivity < 0.1 μS/cm direct electrolyzer feed
- Thermal recovery loops using electrolyzer waste heat
Mineral Recovery & Brine Valorization (Mining Brine)
Rather than treating SWRO concentrate as industrial waste, future-forward plants transform high-TDS reject brine into mineral resources. Through selective electrodialysis and nanofiltration, our ZLD research trains isolate strategic ions including magnesium, calcium, and lithium.
- Near-Zero Liquid Discharge brine concentration up to 220,000 ppm
- Precipitation of commercial-grade magnesium hydroxide
Comprehensive Technical Answers for Procurement & EPC Teams
Critical questions evaluated by chemical engineers, site utility directors, and international purchasing agents before committing capital.
How does Tongjie guarantee CE compliance under the Pressure Equipment Directive (PED)?
All pressurized elements operating above 0.5 bar (including ASME-coded 1200 PSI membrane pressure vessels, cartridge housing chambers, and Super Duplex manifolds) undergo independent notified body review under Module H / H1 or equivalent conformity paths. Every pressure component is accompanied by hydrostatic test reports, material EN 10204 3.1 inspection certificates, and structural calculation dossiers.
What is the typical specific power consumption (kWh/m³) achieved on standard seawater?
For standard ocean seawater (35,000 mg/L TDS at 25°C) operated at a 42% recovery rate, our containerized SWRO units equipped with isobaric pressure recovery devices (PX) achieve a net specific energy consumption (SEC) of 2.8 to 3.2 kWh/m³ across the reverse osmosis high-pressure skid.
How does the system mitigate severe biofouling caused by red tides or algal blooms?
Tongjie engineers deploy a multi-barrier defense consisting of coagulant dosing, automatic dual-media depth filtration, and pressurized hollow-fiber ultrafiltration (UF). In regions prone to intense harmful algal blooms (HABs), we integrate dissolved air flotation (DAF) upstream to remove intact algal cells without releasing intracellular organic matter that fouls SWRO membranes.
What is the expected delivery and commissioning schedule for containerized SWRO plants?
Standard containerized systems (from 100 m³/day up to 2,000 m³/day) feature a factory manufacturing lead time of 6 to 10 weeks. Because the units are fully prefabricated, pre-wired, and wet-tested during Factory Acceptance Testing (FAT) in Shanghai, site erection requires only connecting raw seawater, product discharge, brine disposal, and main power feeds—enabling freshwater production within 5 to 10 days of arrival.
Can the desalination systems operate on off-grid renewable power (Solar PV / Wind)?
Yes. Tongjie has engineered variable-frequency drive (VFD) power control algorithms capable of adapting to fluctuating power curves generated by off-grid photovoltaic and wind hybrid systems. The control system modulates high-pressure pump speeds dynamically while protecting membranes from sudden pressure surges or rapid osmotic depressurization cycles.
What metallurgy is employed to resist pitting corrosion in warm seawater environments?
All high-pressure piping headers, couplings, and valves exposed to high-pressure seawater and concentrated brine are manufactured from Super Duplex 2507 (UNS S32750) or 2205 Duplex Stainless Steel, with a Pitting Resistance Equivalent Number (PREN) above 42. Low-pressure suction piping utilizes schedule 80 PVC, CPVC, or Super Austenitic 904L stainless steel.
Modular Water Systems & High-Salinity Solutions
Precision-built systems delivering continuous uptime for offshore drilling, semiconductor fabrication, and critical regional infrastructure.
Submit Feedwater Profile for Custom Process Projection
Engage directly with Tongjie senior membrane process engineers. Receive complete mass balance calculations, P&IDs, electrical consumption profiles, and equipment GA drawings tailored to your exact site specifications.