Common ion exchange problems and solutions.
Activated Carbons
Symptom: High pressure drop
Cause: Solids build-up
Action: Inspect top of bed for build-up
Symptom: Chlorine in effluent
Cause: Exhausted
Action: Re-bed carbon
Cations
Symptom: High pressure drop
Cause: Solids build-up
Action: Inspect top of bed for build-up
Symptom: Short runs
1. Cause: Resin loss
1. Action: Measure bed height, check internals for integrity, check backwash flow rate
2. Cause: Low resin capacity
2. Action: Oxidized or fouled resin: sample and test resin
3. Cause: Improper regeneration
3. Action: Check regeneration flow rates, contact time, and chemical volumes. Sample and test resin after regeneration for percent conversion to hydrogen form
Symptom: High conductivity from anion unit
Cause: Sodium leakage from cation unit
Action: Check inlet water analysis quarterly for seasonal changes, check regeneration
Anions
Symptom: High pressure drop
Cause: Solids build-up
Action: Inspect top of bed for build-up
Symptom: Short runs
1. Cause: Resin loss
1. Action: Measure bed height, check internals for integrity, check backwash flow rate
2. Cause: Low resin capacity
2. Action: Oxidized or fouled resin: sample and test resin
3. Cause: Improper regeneration
3. Action: Check regeneration flow rates, contact time, and chemical volumes. Sample and test resin after regeneration for percent conversion to hydrogen form
Symptom: Long rinses
Cause: Organic fouling
Action: Sample and test resins, perform caustic brine squeeze
Symptom: High silica
1. Cause: Sodium leakage from cation unit
1. Action: Check inlet water analysis quarterly for seasonal changes, check regeneration
2. Cause: Improper regeneration
2. Action: Check regeneration flow rates, contact time, and chemical volumes. Sample and test resin after regeneration for percent conversion to hydrogen form
NOTE: Off spec or poor performance that occurs abruptly is usually indicative of a mechanical malfunction or sudden change in inlet water conditions or regeneration chemicals. Gradual changes in performance are more likely to be caused by fouling or subtle changes in the inlet water analysis.