Reverse osmosis is driven by pressure higher than the osmotic pressure of the feed solution, allowing water molecules to permeate through a dense separation membrane while most dissolved salts, colloids, and organic matter are retained. It is a core unit for industrial desalination, pure water production, and advanced wastewater reuse.
Separation Principle
- Under operating pressure higher than the osmotic pressure, water molecules permeate in reverse through the dense membrane layer, while dissolved salts are retained on the concentrate side.
- Desalination relies on solution-diffusion and charge repulsion mechanisms, with monovalent ion rejection also at a relatively high level.
- Feedwater requires pretreatment to control turbidity, residual chlorine, and scaling tendency, ensuring membrane element life and stable flux.
Product Features
- High desalination rate and controlled permeate conductivity make it suitable for reuse water production and advanced desalination.
- Flexible modular configuration allows stage and pass combinations according to treatment scale and recovery requirements.
- Forming a stepped process with ultrafiltration and nanofiltration effectively controls membrane fouling and concentrate discharge volume.
- Can be combined with energy recovery devices to reduce specific energy consumption per unit of permeate under medium-to-high salinity conditions.
Application Industries
- Advanced desalination of high-salinity wastewater and reuse water production.
- Pure water and ultrapure water production for the electronics, power, and chemical industries.
- Front-end concentration and volume reduction in ZLD systems, reducing the scale of downstream evaporation and crystallization.
- Desalination treatment for municipal water reuse and industrial circulating cooling water.
Specifications and Models
| Parameter | Unit | Typical value |
|---|---|---|
| Salt rejection rate | % | 98–99.5 (typical) |
| Operating pressure | MPa | 1.0–6.0 (typical, depending on salt content) |
| Recovery per membrane element | % | 10–15 (typical) |
| Feedwater residual chlorine requirement | mg/L | < 0.1 (typical) |
| Feed water SDI₁₅ requirement | — | ≤ 5 (typical) |
| Operating temperature | ℃ | 5–45 (typical) |
The data in the table are common ranges for similar equipment and are for selection reference only; specific specifications, models, materials, connections, and control methods must be confirmed during the selection stage based on water quality, treatment scale, and site conditions.