Dear Shiva, I suggest two ...
Published by Marco Rognoni, Owner at WET, Water Edge Technologies
Dear Shiva,
I suggest two alternative techniques, both more friendlt than using bacteria:
a) in the case of a small flow of water: Just stripping by air in a degassing tower filled with random plastic rings. The high solubility of Ammonia in water and the rather small concentration require for a huge amount of air, and therefore this technique is not suggested for high flow of water
b) filtration through cationic exchanging resins. This technique is well suitable for high flow of water. The necessary regeneration cycle (by acid: example HCl) is justified by the high flow rate of the water to be treated by exchanging ammonia with H+ provided by the regenerated resins.
1 Comment
Shiva, why do you need to remove the ammonia? Is the water for drinking, an industrial process, or is it wastewater?
Marco, why do you say that air-stripping and ion exchange are "more friendly than using bacteria"?
1. Nitrifying bacteria are autortophic, that is they cannot use external organic carbon and are, therefore, safe to use (non-pathogenic). They oxidise the ammonia to nitrate, via nitrite. The WHO guideling value for nitrate (as NO3-) is 50 mg/L (50 ppm), so 30 ppm ammonia (as NH3?) will produce 109 ppm nitrate (as NO3-). So,if required for drinking, some denitrification will be required.
2. Air-stripping surely required pH adjustment into the alkaline region, to convert ammonium to ammonia gas for stripping, and adjusting back to neutral for consumption. Also, transporting ammonia into the atmosphere is not a good idea, from a pollution point of view.
3. Ion exchange creates a waste stream that has to be disposed of, surely that is expensive?
Published by Mike Dempsey, Managing Director, Advanced Bioprocess Development Ltd.