Reverse Osmosis (RO)
Reverse Osmosis (RO) is a membrane process used to remove virtually all dissolved mineral salts, as well as a significant portion of organic substances, microorganisms, and other contaminants from water or treated wastewater. It is one of the key stages in advanced water treatment, enabling safe reuse or preparation for industrial applications.
RO technologies minimize the release of polluted water back into ecosystems by enabling the upgrading and purification of treated wastewater for reuse or for industrial purposes. The process involves forcing water through a semi-permeable membrane, separating impurities and producing two streams: purified water and concentrated brine.
When applied to treated wastewater, RO provides an additional purification step to remove dissolved salts, organic substances, and other contaminants, allowing for reuse or safe discharge to the environment.
Operating Principle
• Natural osmosis occurs when water passes through a semi-permeable membrane from a less concentrated solution to a more concentrated one.
• Reverse osmosis reverses this process by applying pressure higher than the osmotic pressure, forcing water from the more concentrated solution to the less concentrated one.
• The membrane allows water molecules to pass through while retaining over 95–99% of dissolved salts and low-molecular-weight organic compounds.
Technical Specifications
• Filtration range:
• Removal of particles >0.0001 μm
• Elimination of ions (Ca²⁺, Na⁺, Cl⁻, SO₄²⁻, etc.)
• Reduction of nitrates, fluorides, and heavy metals
• Removal of viruses, bacteria, and micro-particles (UF is typically used before RO for prefiltration)
• Operating parameters:
• Operating pressure: approx. 8–20 bar (low salinity) to 40–80 bar (seawater desalination)
• Salt rejection efficiency: 95–99+%
• Water recovery rate: typically 50–85%, depending on feedwater quality and system design
• Membrane module construction:
• Most commonly spiral-wound modules
• Polyamide thin-film composite (TFC) membranes, resistant to high pressure and chemicals
Applications in Water Reuse
• Removal of dissolved salts after ultrafiltration/nanofiltration
• Production of low-conductivity process water for industrial applications (e.g. cooling, boiler feed, food production, pharmaceuticals)
• Potable water production from treated wastewater in Direct Potable Reuse (DPR) and Indirect Potable Reuse (IPR) systems
• Zero Liquid Discharge (ZLD) systems – maximizing recovery and minimizing brine discharge
Typical Process Stages in Wastewater Reuse
• Biological treatment – removal of organic compounds and nitrogen
• Ultrafiltration (UF) – removal of suspended solids and pathogens
• Reverse osmosis (RO) – removal of salts and micro-contaminants
• (Optional) UV disinfection or chlorination – ensuring microbiological safety
• Storage/distribution
Key Advantages of RO in Wastewater Reuse
• Very high efficiency in removing salts and contaminants
• Consistent water quality regardless of fluctuations in treated wastewater parameters
• Direct production of water meeting potable or industrial water standards
We ensure that our systems are designed for minimal maintenance, long service life, and trouble-free operation, reducing operating costs while increasing performance and efficiency. As part of our equipment or full technology line selection process, we offer site-specific assessments and custom-designed technology solutions.
RO technologies minimize the release of polluted water back into ecosystems by enabling the upgrading and purification of treated wastewater for reuse or for industrial purposes. The process involves forcing water through a semi-permeable membrane, separating impurities and producing two streams: purified water and concentrated brine.
When applied to treated wastewater, RO provides an additional purification step to remove dissolved salts, organic substances, and other contaminants, allowing for reuse or safe discharge to the environment.
Operating Principle
• Natural osmosis occurs when water passes through a semi-permeable membrane from a less concentrated solution to a more concentrated one.
• Reverse osmosis reverses this process by applying pressure higher than the osmotic pressure, forcing water from the more concentrated solution to the less concentrated one.
• The membrane allows water molecules to pass through while retaining over 95–99% of dissolved salts and low-molecular-weight organic compounds.
Technical Specifications
• Filtration range:
• Removal of particles >0.0001 μm
• Elimination of ions (Ca²⁺, Na⁺, Cl⁻, SO₄²⁻, etc.)
• Reduction of nitrates, fluorides, and heavy metals
• Removal of viruses, bacteria, and micro-particles (UF is typically used before RO for prefiltration)
• Operating parameters:
• Operating pressure: approx. 8–20 bar (low salinity) to 40–80 bar (seawater desalination)
• Salt rejection efficiency: 95–99+%
• Water recovery rate: typically 50–85%, depending on feedwater quality and system design
• Membrane module construction:
• Most commonly spiral-wound modules
• Polyamide thin-film composite (TFC) membranes, resistant to high pressure and chemicals
Applications in Water Reuse
• Removal of dissolved salts after ultrafiltration/nanofiltration
• Production of low-conductivity process water for industrial applications (e.g. cooling, boiler feed, food production, pharmaceuticals)
• Potable water production from treated wastewater in Direct Potable Reuse (DPR) and Indirect Potable Reuse (IPR) systems
• Zero Liquid Discharge (ZLD) systems – maximizing recovery and minimizing brine discharge
Typical Process Stages in Wastewater Reuse
• Biological treatment – removal of organic compounds and nitrogen
• Ultrafiltration (UF) – removal of suspended solids and pathogens
• Reverse osmosis (RO) – removal of salts and micro-contaminants
• (Optional) UV disinfection or chlorination – ensuring microbiological safety
• Storage/distribution
Key Advantages of RO in Wastewater Reuse
• Very high efficiency in removing salts and contaminants
• Consistent water quality regardless of fluctuations in treated wastewater parameters
• Direct production of water meeting potable or industrial water standards
We ensure that our systems are designed for minimal maintenance, long service life, and trouble-free operation, reducing operating costs while increasing performance and efficiency. As part of our equipment or full technology line selection process, we offer site-specific assessments and custom-designed technology solutions.