Ultra-Pure Water (UPW) treatment

Lenntech designs and delivers ultra‑pure water (UPW) production systems for industrial applications requiring the highest water quality standards, including process design, engineering, equipment supply, installation, and commissioning.

Ultra‑pure water is required in industries where even trace concentrations of dissolved solids, organic compounds, or particles can impact product quality or process performance. Lenntech systems are engineered to achieve extremely low levels of Total Dissolved Solids (TDS), Silica, Total Organic Carbon (TOC), and particles, ensuring reliable operation in highly sensitive applications.

Application context

Ultra‑pure water is used in industries with stringent water quality requirements, including:

• Microelectronics and semiconductor manufacturing
• Hydrogen production (electrolysis make‑up water)
• Pharmaceutical and biotechnology processes
• Power generation and high‑pressure boilers

Typical feed water sources include:

• Municipal water or treated industrial water
• Pre‑treated process water

Key challenges include:

• Achieving extremely low conductivity and TDS levels
• Removing trace organic compounds (TOC)
• Controlling particles and bacteria
• Ensuring consistent water quality 24/7
• Maintaining system stability in continuous operation

In particular, hydrogen production (electrolysis) requires high‑purity make‑up water, similar in quality to UPW systems used in microelectronics.

Typical Lenntech solution

A typical Lenntech UPW system consists of a multi‑barrier process combining advanced filtration, membrane separation, ion exchange, and electro‑deionization technologies, designed for maximum purity and reliability.

Pretreatment

• Multimedia filtration (MMF) or equivalent
• Removal of suspended solids and turbidity
• Protection of downstream systems

Illustration of a multimedia filtration unit

Membrane Separation

• Reverse osmosis (RO), often multi‑stage
• Reduction of dissolved salts and organic compounds
• High‑efficiency removal of TDS

Illustration of a Reverse Osmosis unit

Polishing and Deionization

• Electrodeionization (EDI)
• Ion exchange (IEX) polishing units
• Membrane degassers for dissolved gases removal

Advanced Purification

• Ion exchange (IEX) to prevent TDS build-up in the recirculation loop – especially for electrolyzer applications
• UV oxidation for TOC reduction
• Final filtration for ultra‑low particle concentration

Distribution Loop

• Continuous recirculation (UPW loop)
• Controlled materials (e.g. stainless steel, high‑purity plastics)
• Maintenance of water quality up to point of use

This multi‑step approach ensures removal of contaminants down to trace or ppb levels, meeting the most demanding industrial requirements.

Process Flow Diagram

A typical Lenntech system for ultrapure water treatment is illustrated below:

Design complexity and process control

Ultra‑pure water systems require advanced engineering and precise control due to the extremely low contaminant levels targeted.

Key design considerations include:

• Multi‑barrier treatment trains combining multiple technologies
• Material selection to prevent contamination (electropolished stainless steel, PP, high‑purity piping)
• Full system redundancy to ensure uninterrupted operation
• Continuous monitoring of critical parameters:
  • Conductivity / resistivity
  • Silica
  • TOC (Total Organic Carbon)
  • Particle concentration
  • Temperature and flow

Maintaining very low TDS and TOC levels requires:

• Careful integration of RO, EDI, IEX, UV, and filtration systems
• Minimization of dead zones and stagnation in piping
• Continuous recirculation in distribution loops
• Preventive maintenance and cleaning strategies

The design and assembly of such systems is highly complex, requiring precise integration of multiple process units, instrumentation, automation, and high‑purity materials.

Example system configuration

Flowrate: 30 m³/h

Feed water: Ground water

Technologies:

• Multimedia filtration (MMF)
• Reverse osmosis (RO)
• Electrodeionization (EDI)
• Ion exchange (IEX)
• Ultrafiltration (UF)
• UV oxidation
• Membrane degassing

System configuration:

• Fully automated plant with advanced monitoring (TOC, particles, resistivity)
• Multi‑stage treatment with full redundancy (2 × 100%)
• Modular skid‑based installation (more than 15 skids)
• Continuous UPW distribution loop

Effluent quality:

• Conductivity < 0.06 µS/cm
• TOC < 10 ppb
• Ultra‑low particle concentration
• Controlled temperature

Application: Ultra‑pure water production for microchip manufacturing

Outcome:
The system ensures continuous production of ultra‑pure water with extremely low levels of dissolved solids, organics, and particles, meeting strict semiconductor industry standards while ensuring 24/7 operational reliability.

A more described reference project sheet is available here.

Applications / Reuse of treated water

Ultra‑pure water is used for:

• Semiconductor and microelectronics manufacturing
• Hydrogen production (electrolyzer make‑up water)
• Pharmaceutical and laboratory applications

Benefits include:

• Protection of sensitive industrial processes
• Consistent and reliable product quality
• Reduced fouling and contamination risks
• High process efficiency and stability

Lenntech scope of supply

Lenntech delivers complete UPW production systems, including:

• Process design and technology selection
• Detailed engineering and system integration
• Equipment supply (membranes, EDI, filtration, instrumentation)
• Modular skid‑based construction
• Installation and commissioning
• Advanced monitoring and automation
• After‑sales support and preventive maintenance

9. Optional configurations and flexibility

Depending on application and required purity level, systems may include:

• Multi‑pass RO configurations
• Advanced TOC removal systems (UV oxidation)
• Degassing units for dissolved gases
• Redundant process lines (100% backup)
• High‑purity distribution loops
• Integration with hydrogen production systems

System configurations are tailored to meet strict industry standards and continuous operation requirements.

10. Why choose Lenntech for ultra‑pure water systems

Lenntech combines technical expertise and system integration capabilities that make it well suited for ultra‑pure water applications:

• Proven experience in high‑purity water systems for demanding industries
• Strong expertise in membrane, EDI, and advanced polishing technologies
• Ability to design and deliver complex, multi‑stage treatment systems with full redundancy
• Extensive experience in low TDS, Silica and TOC control at ppb levels
• Capability to integrate advanced instrumentation and real‑time monitoring systems
• Flexible solutions including modular, skid‑mounted systems
• Experience in emerging applications such as hydrogen production

Lenntech supports clients from initial process design through to full‑scale implementation, ensuring reliable and continuous production of ultra‑pure water.