Featured Purification & Membrane Water Systems
Explore our heavy-duty industrial Reverse Osmosis (RO), Ultra-Pure Water (UPW), and produced water recycling units designed and manufactured directly in our Shanghai plant for worldwide delivery.
Industrial Seawater Purification: Engineering Architecture & Thermodynamics
Modern seawater desalination requires balancing high hydraulic pressures against the osmotic pressure of complex hyper-saline feeds. As a wholesale manufacturing and turnkey EPC engineering partner, Shanghai Tongjie Environmental Protection Technology Co., Ltd. (operating since 2010) engineers membrane-based separation platforms that convert raw marine brine (TDS ranging from 32,000 mg/L to beyond 48,000 mg/L in regions like the Arabian Gulf) into potable, process-grade, or boiler-feed water conforming to WHO drinking water limits and ASTM D1193 reagent-grade baselines.
The core of our purification architecture is driven by Thin-Film Composite (TFC) polyamide reverse osmosis membranes, paired with isobaric Energy Recovery Devices (ERDs) and multi-parameter Programmable Logic Controller (PLC) SCADA platforms. By strictly controlling the Silt Density Index (SDI < 3.0) and minimizing concentration polarization across spiral-wound and Disc-Tube RO (DTRO) channels, our plants achieve up to a 99.8% nominal salt rejection rate while slashing Specific Energy Consumption (SEC) to below 2.8 kWh/m³.
Thermodynamic Optimization
Utilizing state-of-the-art ceramic isobaric energy recovery devices, feed-flow kinetic energy is exchanged directly to incoming seawater at up to 96% mechanical efficiency, radically reducing high-pressure pump motor sizing and total operational costs.
Advanced Anti-Fouling Train
Incorporates customized dissolved air flotation (DAF), automatic self-cleaning disc filters, and PVDF hollow-fiber ultrafiltration (UF) pretreatments that virtually eliminate biological biofouling and particulate colloidal fouling in turbulent marine environments.
Precision Boron & Bromide Removal
Multi-pass configurations integrate pH adjustments or selective chelating ion-exchange polishing to extract volatile uncharged boric acid molecules, lowering permeate boron levels below 0.5 mg/L to protect municipal users and agricultural assets.
Strategic Supply Chain & Manufacturing Advantages in China
Procuring industrial-scale seawater purification plants and containerized mobile systems directly from Shanghai Tongjie provides international EPC contractors, municipal water authorities, and industrial facility developers with unmatched cost-efficiency, fabrication speed, and rigorous engineering compliance:
1. Unrivaled Metallurgical & High-Pressure Supply Clustering
Seawater desalination requires specialized anti-corrosive alloys due to high chloride concentrations. Our manufacturing base in Shanghai leverages tier-one domestic supply clusters for Super Duplex Stainless Steel (2507, UNS S32750), 2205 Duplex, Titanium Grade 2, and high-pressure FRP membrane housing vessels rated up to 1200 PSI (83 bar). This geographic integration shortens procurement lead times for specialized piping and valving by 40% compared to Western assemblers.
2. Modular Containerization & Plug-and-Play Factory Pre-Commissioning
We avoid costly, unpredictable field assembly on overseas job sites by completing 100% of skid welding, piping, instrumentation, and Factory Acceptance Testing (FAT) within our Shanghai workshop. Systems are housed within insulated, sea-freight-ready 20-foot and 40-foot HQ shipping containers coated with marine-grade C5-M anti-corrosion paint systems, ready to produce water within 48 to 72 hours of arrival on site.
3. Class II Contracting & Rigorous Quality Systems
Tongjie holds prestigious Class II national contracting qualifications in both Environmental Protection Engineering and Mechanical & Electrical Installation. Accredited under ISO 9001 (Quality Management), ISO 14001 (Environmental Systems), ISO 45001 (Occupational Safety), and European CE directives, our plants fulfill European, Middle Eastern, and North American project compliance standards without modification.
4. End-to-End OEM & ODM Private-Label Capabilities
Global distributors, municipal suppliers, and regional engineering contractors rely on our factory for custom branding, tailored human-machine interfaces (Siemens / Allen-Bradley / Schneider PLC HMI translated into English, Arabic, Spanish, French), specific pipe schedules, and white-label engineering submittals formatted directly for owner approval.
Industry Trends: Next-Generation Desalination & Brine Upcycling
The international water sector is experiencing a paradigm shift from traditional thermal evaporation and high-OPEX membrane desalination toward zero-carbon, intelligent, and resource-recovery architectures. Tongjie's R&D center actively tracks and commercializes several key emerging trends:
| Technological Pillar | Legacy Industry Standard | Tongjie Advanced Factory Standard | Quantified Value & Information Gain |
|---|---|---|---|
| Energy Recovery (ERD) | Francis turbines or pelton wheels (60–75% efficiency) | Isobaric Ceramic Pressure Exchangers (>96% efficiency) | Reduces specific energy to 2.5–2.9 kWh/m³; cuts lifetime OPEX by 35%. |
| Renewable Integration | Grid-dependent or continuous diesel generator running | Off-Grid Hybrid Solar PV + Battery Storage with variable flux control | Eliminates grid constraints; zero-emission water production for remote islands. |
| Brine Recovery / ZLD | Direct coastal discharge of hypersaline reject brine | OARO (Osmotically Assisted RO) + DTRO + Mechanical Vapor Recompression (MVR) | Achieves Zero Liquid Discharge; enables industrial salt recovery and mineral harvesting. |
| Fouling Prevention | Continuous chemical biocide (chlorine) & SMBS de-chlorination | Non-chemical cavitation + physical degasification membranes + automatic Clean-in-Place (CIP) | Extends membrane lifespan from 3 to 6+ years; eliminates chemical residual hazards. |
| Operational Intelligence | Manual periodic testing & localized gauge inspection | Cloud-connected Digital Twin SCADA with predictive flux decay modeling | Predicts membrane scale 3 weeks prior; enables proactive CIP scheduling and 99.5% uptime. |
Macro-Scale Industry Engineering Solutions: Multi-Stage Treatment Train
Every seawater purification system engineered by Tongjie follows a mathematically validated multi-barrier train designed around the client's comprehensive water analysis report (including TDS, seasonal temperature variations, turbidity, SDI, silica, heavy metals, and hydrocarbons). Below is the comprehensive engineering architecture applied across our large-scale facilities:
Intake, Coagulation & Dissolved Air Flotation (DAF)
Deep-sea or beach-well intake water enters the pre-screening stage. For open-intake scenarios affected by red tides, algae blooms, or seasonal turbidity spikes, our skid-mounted DAF units coagulate and float suspended solids, grease, and microalgae to the surface for continuous removal, shielding downstream membranes from acute organic shock loads.
Ultrafiltration (UF) Polishing & Security Micron Filtration
The water passes through pressurized or submerged PVDF hollow-fiber ultrafiltration modules with a nominal pore size of 0.02 to 0.04 microns. This step achieves a continuous Silt Density Index (SDI15) of < 2.5 and turbidity < 0.1 NTU. Prior to the high-pressure pumps, a secondary safety barrier of 5-micron and 1-micron melt-blown polypropylene cartridge filters prevents any stray abrasive particulates from reaching the RO elements.
First-Pass High-Pressure SWRO with Isobaric Energy Recovery
Pressurized by multi-stage centrifugal or positive displacement pumps up to 60–75 bar, feed water flows through ASME Section X-certified FRP vessels housing 8-inch high-rejection SWRO membranes. An integrated isobaric pressure exchanger harnesses the pressure of the reject brine, transferring it to incoming feed water at >96% efficiency, significantly cutting electrical demand.
Second-Pass BWRO & Electrodeionization (RO + EDI Polishing)
For applications demanding potable purity (boron < 0.5 mg/L) or boiler-feed / electronic ultrapure water (< 0.1 µS/cm or 18.2 MΩ·cm), the permeate undergoes a second brackish water RO (BWRO) pass paired with continuous Electrodeionization (EDI). Continuous electrical regeneration eliminates the need for hazardous acid and caustic chemical regenerants.
Remineralization, Disinfection & Brine Upcycling / ZLD
Permeate intended for drinking networks is remineralized via calcite limestone dissolution filters and injected with sodium bicarbonate to restore the Langelier Saturation Index (LSI) to a non-corrosive neutral state, followed by UV and chlorine dioxide disinfection. Meanwhile, the hyper-saline reject stream is concentrated via specialized Disc-Tube RO (DTRO) up to 120 bar and routed to MVR crystallization units for complete Zero Liquid Discharge (ZLD).
Localized Application Scenarios & Sectoral Deployments
Tongjie's seawater purification systems are engineered to withstand extreme climates, remote geographies, and demanding industrial conditions across key global sectors:
Island Municipalities & Coastal Resorts
Compact, low-noise containerized SWRO units operate reliably on small islands in Southeast Asia, the Caribbean, and the South Pacific. With container-integrated acoustic dampening, automated clean-in-place (CIP) cycles, and mineralizer stages, units deliver WHO-standard drinking water directly to municipal distribution networks or luxury resorts without relying on costly mainland freshwater barging.
Coastal Chemical, Refining & Power Plants
Thermal and nuclear power stations, along with petrochemical complexes, require continuous demineralized water for high-pressure boilers and cooling tower makeup. Our dual-pass SWRO + EDI plants purify raw coastal seawater into boiler-feed water with silica < 5 ppb and conductivity < 0.1 µS/cm, completely decoupling industrial operations from municipal water supply constraints.
Offshore Oil Platforms & Marine Vessels
Marine environments demand non-sparking explosion-proof electrical controls (ATEX/IECEx certified) and ultra-compact, vibration-resistant footprints. Tongjie fabricates lightweight skid systems utilizing Super Duplex 2507 stainless steel and marine-grade titanium, providing drilling crews with reliable utility and drinking water in the Gulf of Mexico, North Sea, and Southeast Asian oilfields.
Mining & Remote Construction Infrastructure
Mining operations along arid coastlines (such as in Chile, Peru, and Western Australia) demand rugged systems that handle high suspended solids, heavy metal spikes, and dust. Our containerized plants include automated backwashing multimedia filters and solar-ready DC electrical buses, enabling continuous off-grid operation at mining camps and remote mineral processing facilities.
Emergency Relief & Military Camps
In disaster response scenarios, containerized plants can be transported by standard flatbed truck, airfreight, or sea container ship. Equipped with on-board diesel generation, self-priming intake pumps, and rapid quick-connect hose manifolds, these systems produce safe, pathogen-free water within hours of deployment on disaster-struck coastlines.
Zero Liquid Discharge & Mineral Extraction
Beyond conventional desalination, our hyper-high-pressure membrane systems concentrate brine reject streams to TDS levels exceeding 140,000 mg/L. This concentrated stream feeds downstream crystallizers for commercial table salt production, industrial sodium sulfate extraction, or lithium/magnesium chemical recovery in advanced circular economy plants.
Global Enterprise Procurement: Quality Protocols & RFP Criteria
International engineering, procurement, and construction (EPC) contractors evaluating wholesale seawater purification manufacturers must verify critical structural, electrical, and process guarantees to eliminate project execution risks. When issuing requests for proposals (RFPs), procurement managers should reference these essential factory benchmarks:
Factory Acceptance Testing (FAT) Rigor
Never accept water treatment skids that have only undergone visual dry inspection. At Tongjie’s Shanghai facility, every system undergoes a dynamic wet test: high-pressure hydrostatic testing at 1.5 times the maximum design pressure for 4 hours, continuous 24-hour sensor loop calibration, PLC emergency-stop fail-safe verification, and factory water quality analytics across the pressure gradient.
Traceability & Material Certification (EN 10204 3.1)
High-chloride environments cause rapid catastrophic pitting and crevice corrosion if sub-standard stainless alloys are substituted. Tongjie provides complete mill test certificates (MTC) conforming to EN 10204 3.1 for all wetted pressure piping (Super Duplex 2507 / 2205), radiographic weld inspection reports, and ASME Section X documentation for all composite pressure vessels.
Control Automation & Cyber-Secure Connectivity
Overseas plants frequently operate in remote regions with lean operating teams. Our standard automation architecture features Siemens S7-1500 or Allen-Bradley ControlLogix PLCs integrated with redundant Ethernet/IP or Modbus TCP protocols, offering encrypted cloud-based remote telemetry, automatic fault logging, and secure remote diagnostic capabilities for off-site engineers.
Total Cost of Ownership (TCO) Sizing Models
Membrane replacement, electrical consumption, and antiscalant consumption make up more than 85% of a desalination plant's 20-year lifecycle cost. Tongjie balances initial capital expenditure (CAPEX) with operational expenditure (OPEX) by sizing conservative membrane flux rates (11.5–13.5 LMH), incorporating pressure-exchanger recovery, and running projection modeling on industry-standard platforms.
Advanced Modular Desalination & High-Salinity Concentration Systems
Explore additional membrane systems, including high-salinity brine concentrators, compact commercial SWRO skids, deoxygenation degassing modules, and zero-liquid-discharge (ZLD) crystallization packages:
Frequently Asked Questions: Technical Engineering & Factory Procurement
Direct answers to technical, operational, and commercial questions asked by international buyers, EPC contractors, and utility project managers before placing wholesale orders:
Request an Engineered Water Treatment Sizing & Factory Proposal
Submit your raw water chemistry analysis, site location, target product flow rate (m³/day or GPD), and purity requirements. Our senior membrane process engineers will generate a comprehensive design package—including mass-balance calculations, P&ID diagrams, energy recovery projections, and an itemized FOB/CIF quotation within 24 to 48 business hours.