Reverse Osmosis (RO) Drinking Water Plant — 2,500 m³/day
At a glance
- End use: Potable/drinking water
- Capacity: 2,500 m³/day permeate
- Process: Media filtration → Micron filtration → Two-stage RO → pH & mineral adjustment → Chlorine dosing (disinfection + residual)
- Our role: Process design, project management, commissioning
- Key challenges: High hardness (Ca, Mg) and dissolved iron
- Outcome: Stable operation at the designed recovery with low fouling rates and compliant product water
Background & objectives
A client required a robust drinking-water system capable of reliably producing 2,500 m³/day of permeate. Our engineers were engaged to design, project manage, and commission a complete RO-based treatment train to deliver potable water aligned with applicable drinking water guidelines.
Challenges
- High hardness (Ca²⁺, Mg²⁺): Elevated scaling potential on RO membranes, particularly at higher recoveries.
- Dissolved iron: Risk of oxidised iron precipitating and causing particulate fouling/pressure drop across membranes.
- Reliability at target recovery: Achieving the desired recovery without compromising membrane life or cleaning frequency.
Solution approach
Pretreatment engineered for stability
- Media filtration selected to remove oxidised iron and reduce particulate load.
- Micron (cartridge) filtration downstream to polish particulates and protect the RO.
RO configuration & recovery management
- Two-stage RO layout to balance flux and recovery while controlling concentrate scaling risks.
- Recovery setpoint chosen from ion-balance and scaling‐tendency evaluations to ensure sustainable operation at the design duty.
Scaling & fouling control
- Antiscalant dosing optimised for the raw-water chemistry (hardness species), enabling target recovery with low fouling rates.
- Operating envelope defined (pressure, permeate flux, differential pressure limits) to maintain stable performance.
Post-treatment for potable use
- pH and mineral adjustment for corrosion control and palatability.
- Chlorine dosing for final disinfection and residual protection in the distribution system.
Process flow
Raw water → Media filter → Micron filter → RO Stage 1 → RO Stage 2 → pH & mineral adjustment → Chlorine dosing → Storage/Distribution
