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  for Metal Finishing since 1989
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Mixed bed polisher regeneration effluent

Lately we are facing with high chemical oxygen demand result in our waste water treatment plant. We did trouble shoot the culprit of this subject. One of the potential source is Mixed Bed Polisher regeneration effluent where the results are between 400 to 600 ppm. The same result was found after we replaced with new resin.

Please advice on the cause of high COD in Mixed Bed Polisher regeneration effluent and the standard limit for this parameter

Harizan bt Hawari
FERTILIZER - GURUN, KEDAH
2005

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2005

While there is some amount of organic material that is released from ion exchange resins (particularly new resins), it is more likely the high COD concentration in your regeneration wastes is due to natural causes.

Ion exchange resins also remove and concentrate naturally occurring organic materials found in water (mainly on the anion resin) and releases most of them when they are regenerated.

Lyle Kirman
consultant - Cleveland Heights, Ohio

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If the M/B is a polisher, then presumably the water is deionized by either an R/O or dual bed system upstream. You may have excessive carbonates in your feed, resulting in a leakage of primarily CO2 from the primary system. Depending on how the oxygen demand is determined, the cause may not be entirely "organics" that are deemed objectionable for discharge.

Juzer Jangbarwala
2005