Water and Wastewater.com Help Forum - Ammonia Removal

Water and Wastewater.com Help Forum - Ammonia Removal

"I work at a military installation in the midwest and we have been required to test for ammonia since last year and we have been consistently at or over our levels ever since. It is a 3 MGD, primary clarifiers, 4 standard rate tricking filters, anaerobic digesters, secondary clarifiers, sand filtration. We have tried various biological parameters (PH, breakpoint chlorination, lime, etc.) with little success. We even added mechanical aerators to our chlorine contact chambers but the effects were minimal. Was wondering if someone else could offer some suggestions for our nagging ammonia problems. "

Answer
Dear Moeagle,
as a pacifist I would say the only sustainable solution to your problem is to shut down the military installation.
As a chemical engineer I like to remark that you have an oversupply of nitrogen nutrients.
Ammonia liberates when the pH gets alkaline. Therefore application of lime is contra productive. Further, I cannot see how chlorination should improve the situation, it would be more straight forward to add hydrochloric acid directly. Would not recommend that either.
Using an active sludge process one would establish a working nitrification/denitrification process.
Given your configuration I would suggest to include a trickling filter filled with bark mulch (a substrate deficient with nitrogen nutrients) in front of your process.

Kind regards
T. Sobisch

Victor Santa Cruz
Moeagle/Sobisch:

The addition of Cl transforms NH3-N into mono/di chloramines and there comes a point in the disinfections process (primarily) where endpoint chlorination occurs. This is one process to reduce ammonia in wastewater treatment plant effluents. Air stripping is one way to reduce ammonia. A step or cascading effect removes some of the ammonia. Depending on the constituents present in the primary influent such as alkalinity, DO, and BOD nitrification may or may not occur. You will lose alkalinity with nitrification and the minimum alkalinity that must be present in your primary influent should be ~70 mg/L. Trickling filters are capable of removing some of this ammonia.

Further comments ???