Reverse osmosis is unforgiving: a few hours of wrong antiscalant dose or a chlorine excursion can shorten membrane life by years. Pretreatment dosing is the cheapest insurance in the train.
The Operating Reality
An RO train doses antiscalant ahead of the membranes, adjusts pH for boron or silica control, feeds biocide to control biofouling, and may add bisulphite for dechlorination.
Why Manual Dosing Falls Short
Manual antiscalant feed either overdoses (wasting chemical, risking fouling from the additive itself) or underdoses (letting scale form on the membrane surface). Precision dosing keeps recovery stable.
How Automatic Chemical Dosing Fits
- Plunger metering at ±0.5% accuracy holds low antiscalant doses repeatable, which is the dose range where manual error is largest.
- pH and ORP feedback lets the controller correct for feedwater changes instead of waiting for a lab result.
- Twelve chemical classes are supported on one skid, so antiscalant, pH correction and biocide run together.
Selection Checklist
- Define the control signal first (pH, ORP, conductivity or flow-proportional) before sizing the pump.
- Size the metering pump to the lowest expected dose with margin, not to the peak dose.
- Confirm chemical compatibility of wetted parts (316L, PVC, PVDF) with every product to be fed.
- Provide containment, leak detection and dry-running protection in the dosing room design.
- Integrate the skid with PLC, DCS or remote telemetry so dose is visible in the control room.
Related Products
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FAQ
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