The chemical conditioning that makes a desalination feed membrane-safe — coagulant, acid, antiscalant, dechlorination and biocide, accurately dosed and controlled.
SWRO Intake & Pre-Treatment for Desalination
Chemical dosing turns screened, filtered seawater into a membrane-safe RO feed. Coagulant agglomerates fines for the filters; acid and antiscalant prevent scaling; sodium metabisulphite removes residual chlorine that would oxidise the membranes; and biocide dosing controls biofouling. Accurate, interlocked dosing is essential to membrane life.
Conditioning the feed across the train
Ferric chloride/sulphate ahead of media/UF to capture colloids.
Sulphuric acid trims pH to manage carbonate scaling and coagulation.
Threshold inhibitors stop CaCO₃, sulphate and silica scaling on the membranes.
Sodium metabisulphite removes residual oxidant before the RO.
Intermittent biocide controls biofouling in pre-treatment.
Accurate, interlocked dosing pumps with online feedback.
Typical engineering envelope
| Chemical | Typical Dose | Purpose |
|---|---|---|
| Ferric coagulant | 1–5 mg/L as Fe | Coagulation before filters |
| Sulphuric acid | to pH 6–7 | Scaling & coagulation control |
| Antiscalant | 1–3 mg/L | CaCO₃ / sulphate / silica scale |
| SMBS (dechlor) | ~1.8–3 mg/L per mg Cl₂ | Protect RO from oxidant |
| Biocide | Periodic shock | Biofouling control |
Continue across the SWRO intake & pre-treatment series
A companion stage of the SWRO pre-treatment train.
Read MoreA companion stage of the SWRO pre-treatment train.
Read MoreA companion stage of the SWRO pre-treatment train.
Read MoreA companion stage of the SWRO pre-treatment train.
Read MoreA companion stage of the SWRO pre-treatment train.
Read MoreThe intake-systems hub these stages belong to.
Read MoreOur desalination engineers design the complete intake and pre-treatment train — coagulation & dosing and every stage — to deliver a low-SDI, membrane-safe feed at minimum lifecycle cost.
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