Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

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Demineralizer

Please explain why cation exchanger is located before anion exchanger and whether they can be swapped.

Regards,

Abdulghani
- Jubail, Saudi Arabia
2002

You do the cation exchange first because the anions are more universally soluble than the cations. If the sulphate or nitrate or chloride was soluble in the original incoming stream it will probably remain soluble when you replace the cations with hydrogen, acidifying the stream. If you remove the anions first, the cations are quite likely to precipitate as an hydroxide and make a mess.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

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