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WaterSolutions Membranes Troubleshooting - High Salt Passage

Symptom	Possible Causes	Solution
High Salt Passage and High Flow (Low Feed Pressure)	Membrane Barrier Layer Oxidation	Replace affected elements and eliminate source of oxidant. Lead elements will be damaged first and can be localized with probing (72KB PDF).
	Membrane Barrier Layer Delamination (back-pressure)	Replace affected elements. Damaged elements can be localized with profiling (77KB PDF) and probing (77KB PDF).
	Improper Disinfection (iron present)	Replace affected elements. Elements should be cleaned of iron (39KB PDF) or other metals (279KB PDF) before any cleaning with potentially oxidizing disinfectants. Lead elements will be damaged first and can be localized with probing (77KB PDF).
	Acute Mechanical Damage to Elements	Replace affected elements. Damaged elements can be localized with profiling (77KB PDF) and probing (77KB PDF).
High Salt Passage and Normal Flow	Leaking or Missing O-rings	Localize leaking seals with profile and probe. Replace worn or cut o-ring seals. Use proper lubricant and shim (37KB PDF) to minimize movement and wear on seals.
	Membrane Surface Abrasion	Probe (77KB PDF) will indicate the damage. Correct pretreatement, replace elements.
	Broken Internal Parts	Localize leaking parts with profile (77KB PDF) and probe (77KB PDF). Replace broken parts including elements if product water tubes are found broken. Use proper lubricant and shim (37KB PDF) to minimize movement and wear on seals.
High Salt Passage and Low Flow (High Feed Pressure)	Organic Fouling	Check feed water for high levels of organics, or oil, or operating at excessive recovery. Clean elements. Refer to prevention guidelines. Good for some organics, not for polyelectrolytes. Difficult to remove some organics like oils. Can try detergents with pH 12.
	Carbonate Scale	Clean elements at pH 2 following standard procedures. May need extensive and repetitive cleanings. May not be economical to attempt repeated cleanings, therefore replace elements. Weighing tail element can give a measure of extent of scaling. Refer to scale control (30KB PDF).
	Sulfate Scale	Clean elements. May need extensive and repetitive cleanings. May not be economical to attempt repeated cleanings, therefore replace elements. Weighing tail element can give a measure of extent of scaling. Refer to scale control (30KB PDF).
	Membrane Plugging and Surface Abrasion with Foreign Material (like sand)	Probe will indicate the damage. Correct pretreatment and replace elements.
	Silica (colloidal)	Clean (279KB PDF) elements. Very difficult to clean, modify pretreatment, lower recovery.
	Iron Oxide Fouling	Clean (55KB PDF) elements.
	Other Heavy Metal Oxide Fouling	Clean (279KB PDF) elements.
	Iron Sulfide Fouling	Clean (279KB PDF) elements. Eliminate source of air.
	Calcium Fluoride Scale	Clean (279KB PDF) elements.
	Phosphate Scaling	Overfeeding phosphate, difficult to impossible to clean, replace elements.
	Silica Scale	Clean (279KB PDF) elements. Very difficult to clean, modify pretreatment, lower recovery.

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