Reverse osmosis water purification systems remove 95-99% of dissolved salts, 99%+ of organics, and effectively all bacteria and particulates — delivering the consistent water quality needed for filter cloth washing, laboratory dilution, boiler makeup, and pharmaceutical process water. Here is how an industrial RO system is sized and what to specify.
How Industrial RO Works
Tap or well water passes through three barrier stages: pre-treatment (sediment filter + activated carbon + softener or anti-scalant injection), the RO membrane stage, and post-treatment (storage tank + UV lamp + polishing filter). At the heart, a high-pressure pump (10-25 bar) forces water across a semi-permeable thin-film composite (TFC) polyamide membrane. Pure permeate passes through, while concentrated reject brine flushes contaminants away.
Typical recovery (permeate ÷ feed) is 50-75% for brackish water and 35-45% for seawater. Senjie industrial RO units run continuously at 70-85% efficiency with proper anti-scalant dosing.
When to Choose RO vs Ultrafiltration vs Deionization
RO is the right answer for total dissolved solids (TDS) reduction. For removing suspended solids and colloids only — like polishing filter press filtrate before discharge — filter cloth filtration or ultrafiltration is faster and cheaper. For ultra-pure water (less than 0.1 µS/cm), follow RO with mixed-bed ion exchange or EDI (electrodeionization).
Common Applications
- Filter cloth washing — preventing mineral scale buildup on filter media (extends cloth life 2-3x)
- Process makeup water — for chemical and pharmaceutical batches
- Laboratory dilution — analytical-grade water for QC labs
- Boiler feed — preventing scale in low-pressure steam generators
- Battery & semiconductor — ultra-pure water for cell assembly
- Cooling-tower makeup — extending cycles of concentration
- Bottled water — feed for beverage production
Specifications & Customization Options
- Capacity: 0.25 – 100 m³/h permeate
- Membrane type: Brackish water (BW), seawater (SW), low-fouling (LE) TFC polyamide
- Pre-treatment options: Multi-media filter, activated carbon, softener, anti-scalant dosing
- High-pressure pump: Stainless-steel multistage centrifugal, VFD-controlled
- Pressure vessel material: FRP standard, 316L stainless for sanitary duty
- Control: PLC + HMI with online conductivity, ORP, and flow monitoring
- Post-treatment: UV disinfection, EDI for ultra-pure, mixed-bed polisher
FAQs
How long do RO membranes last? 3-5 years with proper pre-treatment. The biggest killers are chlorine attack (degrades polyamide within hours), scale (calcium carbonate or sulfate fouling), and biofouling. Monitor permeate conductivity weekly — a 15% rise from baseline signals end-of-life.
What feedwater pretreatment do I need? At minimum: 5 µm sediment filter, activated carbon (chlorine removal), and anti-scalant dosing. For hard water (TH above 200 mg/L CaCO₃), add a softener or use scale-inhibiting chemistry to prevent CaCO₃ and CaSO₄ scaling on the membrane.
What is the reject water for? Reject brine has 2-3x the TDS of the feed but is still usable for non-process duties: floor washing, irrigation of salt-tolerant plants, dust suppression, or in some plants, cooling-tower blowdown makeup.
Need an RO system specified for your plant? Send Senjie a water analysis (TDS, hardness, chloride, silica, free chlorine, SDI), target permeate quality, and required flow — we’ll design a multi-stage RO system from our water treatment catalog.