Nanofiltration: Selective Treatment for Controlled Water Quality
Nanofiltration (NF) is a membrane filtration process intermediate between ultrafiltration and reverse osmosis.
It allows for the reduction of hardness, organic matter, micropollutants, and some dissolved salts, while preserving certain essential minerals.
This process stands out as an effective solution for the production of softened, partially demineralized, or weakly mineralized water, meeting industrial, hospital, or drinking water needs.
At SFEC, we design, manufacture, and maintain custom nanofiltration systems, integrated into global treatment chains.
Our objectives:
Optimize water quality according to process requirements
Reduce treatment costs and energy consumption
Ensure the longevity of installations and performance stability
Operating Principle of a Nanofiltration System
Nanofiltration relies on water passing through semi-permeable membranes with nanometric pores (approximately 0.001 µm).
Under pressure, these membranes allow water and small monovalent ions (Na⁺, Cl⁻) to pass through, but retain divalent ions (Ca²⁺, Mg²⁺) and large organic molecules.
Pre-filtration
Removal of particles and free chlorine to protect membranes
Pumping under moderate pressure (5 to 15 bars)
Water circulation through membrane modules
Selective Filtration
Separation between permeate (filtered water) and concentrate (reject)
Post-treatment
pH adjustment or sterilization depending on the final application
Our Custom Nanofiltration Solutions
SFEC offers several ranges of equipment adapted to industrial constraints and water quality objectives:
Industrial Nanofiltration Units
- Treatment capacity from a few m³/h to several hundred
- High-performance spiral-wound membranes
- Automatic control and digital supervision
Nanofiltration Systems for Process Water
- Selective reduction of hardness and conductivity
- Improvement of installation energy efficiency
- Integration into global treatment lines: softening, reverse osmosis, UV
Nanofiltration for Food Beverage and Hospital Applications
- Elimination of micropollutants and disinfection by-products
- Improvement of taste and microbiological purity
- Hygienic design compliant with sanitary standards
Combined Installations
- Coupling with softeners or reverse osmosis units for enhanced efficiency
- Energy recovery and optimization of discharges
Advantages of Nanofiltration
Nanofiltration improves water quality while optimizing industrial performance.
By selectively removing hardness, organic matter, and micropollutants, it reduces operating costs and durably protects installations.
Selective Hardness Reduction
Limits scale formation and extends equipment lifespan.
Elimination of 90 to 95% of organic matter and heavy metals
Improves the purity and stability of process water.
Significant reduction of micropollutants, pesticides, and nitrates
Ensures safer water compliant with sanitary requirements.
Reduced Energy Consumption
Operation at moderate pressure for high efficiency and controlled costs.
System Protection
Reduction of deposits, corrosion, and maintenance operations.
Areas of Application
Nanofiltration is applicable wherever water quality must be controlled to meet technical, sanitary, or environmental requirements:
- Pre-treatment before reverse osmosis
- Production of softened industrial water
- Treatment of tap or surface water
- Food Beverage Industry (drinks, washing, preparation)
- Hospitals and laboratories
- Reduction of nitrates and pesticides in drinking water
- Treatment of recycled and process water
Questions and Answers
What is the Difference between Nanofiltration and Reverse Osmosis?
Nanofiltration primarily retains divalent salts and organic molecules, while reverse osmosis eliminates almost all dissolved salts.
Does Nanofiltration Remove Limescale?
Yes, it retains the majority of calcium and magnesium ions responsible for hardness.
What Operating Pressure is Required?
Approximately 5 to 15 bars, compared to 15 to 70 bars for reverse osmosis.
Is Water from Nanofiltration Potable?
Yes, it retains residual mineral content favorable for consumption.
Is Pre-Treatment Necessary before Nanofiltration?
Yes, mechanical filtration and partial softening are often recommended to protect the membranes.
What is the Efficiency of a Nanofiltration Installation?
Between 70 and 85%, depending on the inlet water quality and system configuration.
SFEC, global water treatment expert
Nanofiltration often constitutes an intermediate or complementary step within a treatment chain:
SFEC supports you from technical study to maintenance, with personalized and scalable solutions, designed to meet your quality and performance challenges.
Do you wish to improve the quality of your water while reducing your operating costs?
Our engineers assist you with the design and installation of a nanofiltration unit tailored to your needs.