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Relationship between chloride concentration and sodium hypochlorite concentration

Can I determine what the concentration of sodium hypochlorite in solution is from chloride analysis data? Is this a simple stochiometric relationship? this question is in relation to membranes with a chemical incompatibility to sodium hypochlorite >200ppm. The food processing industry uses sodium hypochlorite to disinfect processing equipment and pipes.

Elaine Pidgeon
- Brisbane, Australia
2003

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Yes, if no Cl-containing byproducts, and corrections are made for volumetric changes and initial chloride concentration. In terms of mass, e.g., grams, Residual NaOCl = Initial NaOCl � 2.10 x [final Cl � initial Cl] If no volume change, the equation is valid for concentration, e.g., ppm. Do some analyses before relying on this equation; I would not be surprised to find some sodium chloride in sodium hypochlorite cleaners.

You should still use a carbon filter to protect the membrane system. Consider adding an ORP meter and alarm on the feed line to the filter to detect hypochlorite spikes.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2003