hypochlorite oxidation of ammonia: ORP control
hypochlorite oxidation of ammonia: ORP control
(OP)
I am developing a program to remove NH3 from wastewater (ammonia; 500-600mg/L) by using sodium hypochlorite to oxidize ammonia. Has anyone any experience with this kind of application? A literature search shows that it can be done at pH 7 - 8 and controlled by ORP. I cannot find any ORP value to use to control the reaction. Any information will be greatly appreciated.





RE: hypochlorite oxidation of ammonia: ORP control
The stoichiometric amount of chlorine to ammonia is approximately 10:1. So you will be adding a large amount of chlorine.
Assuming the conncentration is constant, you can add chlorine in proportion to the flow. A chlorine residual analyser can be used to limit overfeeding of chlorine.
Have you considered alternative methods of disposal? Ammonia is commonly used as a nutrient in the activated sludge process. You may be able to dispose of this material for little cost.
http://www.rmtech.net/Aqua%20Ammonia.htm
RE: hypochlorite oxidation of ammonia: ORP control
What kind of residence time is needed and what are the by products: chloramines?
Thanks Bernard
RE: hypochlorite oxidation of ammonia: ORP control
Breakpoint chlorination would have have to be used. This means that enough chlorine would have to be added to oxidize the chloramines. There would be a small amount of chloramines present. Some choramines are resistant to ozidation.