Why It Matters
Concentration of feed in the RO reject stream supersaturates CaCO3, CaSO4, BaSO4 and silica at the tail membranes, cutting flux. Design uses threshold antiscalants dosed to feed to suppress nucleation in the concentrate
Solution Approach
Concentration of feed in the RO reject stream supersaturates CaCO3, CaSO4, BaSO4 and silica at the tail membranes, cutting flux. Design uses threshold antiscalants dosed to feed to suppress nucleation in the concentrate RawSource supplies the base chemicals that go into these programs. We can help with product selection, grade matching, and sourcing from multiple origins for supply security.
Typical Treatment Workflow
1
System Assessment
Characterize operating conditions—fluid composition, temperature, pressure, flow rates—and benchmark current treatment performance.
2
Chemistry Selection
Match base chemicals to your operating envelope. Factor in compatibility with existing programs, regulatory constraints, and downstream impacts.
3
Dosage & Delivery
Determine optimal treat rates through jar testing or field trials. Configure packaging (drums, totes, ISO tanks) to match consumption and storage logistics.
4
Monitoring & Adjustment
Track KPIs—coupon rates, residuals, separator performance, water quality. Adjust chemistry and dosage as conditions change.
Recommended Chemistries (5)
Hydroxyethylidene Diphosphonic Acid
CAS 2809-21-4
Phosphate Esters & Derivatives
Primary CaCO3 scale inhibitor
HEDP threshold-inhibits CaCO3/CaSO4 in the RO reject at low dose; widely accepted as membrane-compatible
Melting Point: 198-199 Boiling Point: 578.8 Solubility: 1.15e+01 g/L
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DTPMPA (Diethylenetriamine Penta(methylenephosphonic acid))
CAS 15827-60-8
Phosphate Esters & Derivatives
High-temperature phosphonate
Strong against sulfate scales (BaSO4/CaSO4) and stable at the high LSI of the concentrate; protects tail elements
Physical Description: Solid; 49-51% Aqueous solution: Clear amber to …
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Polyepoxysuccinic Acid (PESA)
CAS 51274-37-4
Phosphate Esters & Derivatives
Chelation / Sequestration
Phosphorus-free polycarboxylate antiscalant (low eutrophication/discharge concern) effective on carbonate and sulfate scales in membrane plants
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HPAA (2-Hydroxyphosphonoacetic Acid)
CAS 23783-26-8
Phosphate Esters & Derivatives
Chelation / Sequestration
Threshold inhibitor with good calcium tolerance, broadening scale coverage across variable RO feedwaters
Physical Description: Brown liquid. Slight acrid odor
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Sodium Hexametaphosphate (SHMP)
CAS 10124-56-8
Specialty Additives
Chelation / Sequestration
Classic low-cost polyphosphate that sequesters Ca2+/Ba2+ and threshold-inhibits carbonate scale on RO feed
Physical Description: Polymeric sodium metaphosphates: Clear hygrosco… Solubility: CLEAR, HYGROSCOPIC GLASS; MP 628 °C; SOL IN WAT… Decomposition: When heated to decomposition it emits toxic fum…
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