Oil fouling occurs when oil coats the surface of ion exchange resin beads, making it difficult for ions to pass through. This can cause the resin to lose its efficiency and become less effective.

 Oil fouling occurs when oil coats the surface of ion exchange resin beads, making it difficult for ions to pass through. This can cause the resin to lose its efficiency and become less effective. 

Causes

Oil field water: Softeners used to treat oil field water are often fouled by oil. 

Dissolved oil: Even when there is no free oil in the water, dissolved oil can still foul the resin. 

Emulsions: Emulsions can plug and foul the resin, similar to suspended solids. 

Cleaning 

Non-ionic surfactants: Lightly fouled resins can be cleaned with a non-ionic surfactant like Triton X-100 or dishwashing detergent.

Backwashing: The resin should be thoroughly backwashed.

Agitation: Agitate the resin while it's soaking in the surfactant solution.

Rinsing: Rinse the resin until foaming stops.

Regeneration: Regenerate the resin before using it again.

Prevention 

Inspect, sample, and clean the resin regularly.

Use high quality water.

Use water pretreatment to remove contaminants from the water source.