Ammonia removal from Pit Waters

[Dwee]

We have a discharge limit of 2mg/L on ammonia, which may present a problem for our pit seepage water. We do have a holding pond for storage, and a treatment plant for solids removal. What are best methods and your experiences in treating ammonia in cold water (approx 4deg C)?

 

[ChrisDerrick]

With NH4 at such low concentrations "Breakpoint Chlorination" should be investigated.

Try:
"Wastewater Engineering, Treatment, Disposal, and Reuse"
Metcalf and Eddy, published by McGraw Hill

or

"Chemistry for Environmental Engineering"
Sawyer, McCarthy, Parkin, published by McGraw Hill

Or

probably any good wastewater handbook

There is a good description of breakpoint chlorination in the text of these books.

good luck

 

[oxilume]

Dwee,

Break point chlorination is not the answer for removing ammonia from water. When ammonia is chlorinated the final product is nitrogen trichloride. See my US patent #5,832,361 with respect to the dangers of NCl3 (

http://www.uspto.gov).

Explosions have occured within the Chlor-Alkali industry. If anyone truely knew how to remove all ammonia from water it would be the answer for the medical industry with respect to water for injection (WFI). Ammonia passes through virtually every known type of filter (nano-filtration, RO, etc.)

At a low water temperature you may still beable to remove the ammonia to within your discharge limits of 2mg/l. Try this website:

http://www.revextechnologies.com

The Revex MTU is a unique patented stripper.

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Special note from member bimr posted Jan 12, 2006
:
Breakpoint chlorination is probably the best option. The trichloride species does not dominate in the chlorination reaction. The representative reaction is: 3HOCl + 2NH3 --> N2 + 3H2O + 3HCl It is only possible to get nitrogen trichloride when you are dosing with excess chlorine (weight ratios Cl2:N greater than 10:1) or you are at a pH below 4.4. Further, this is not typical in the optimum operating range for breakpoint chlorination of between 6-7 pH units. The trichloride reaction: 3NaOCl + NH3 --> 3NaOH + NCl3 Bubbling chlorine gas through a solution of ammonium nitrate (and other ammonium salts) is one method to obtain the yellow droplets of nitrogen trichloride. ----bimr