[Riley_5000]

Hi

I have a high total ammonia water (336mg/l as N) in my feed water. I want to know how much NH3 removal I can get if increase the pH in my Neutralization reactor? How do I calculate this (partial pressures probably).

The water pH is currently 3.2. I've managed to work out that at a pH of 8.5 my total free (unionised) NH3 is 62.15mg/l.

How can I calculate how much of this NH3 will leave to atmosphere as gas?

Thanks

[eugenedakin]

Hello Riley_5000,

Unfortunately, there is a very high chance that there is little to no correlation based on a pure pH measurement.  The solubility and retention of Ammonia greatly depends on temperature, concentration of ammonia in the air phase, types of contaminants in the water (salts, emulsifiers, treating chemistry, corrosion products etc.).  Agitation also is a factor (more agitation causes more ammonia to be removed from the solution).

I wish you the best with your calculation.

Sincerely,

Eugene

[Gerard]

i agree with eugene...
uhm there is a research with the nitrogen uptake of ulva lactuca the amount of nitrogen uptake in tropical areas are greater than that of colder seas...
research for ulva on the net...

[technologist]

Eugene is right & U can understand it as below.

1. PH adjustment is ammonia removal or any other gas removal is to break the chemical bonding with H+ ions or OH- ions.

2. Once the chemical bonding is broken than ohysical removal is like other processes where the separation is goerned by other operating parameters.

3. If you dont go for step-1 U need much higher energy for separation which is a sum of chemical energy + physical separation energy.

So just by adjusting pH U can only say that free or dissolved ammonia (Not ammonium NH4+ ion) is this much which can be separated by physical process. (Thats why free ammonia terms is used)...

Hope it is clear

[C6H8O7]

Hello Riley_5000,

Unfortunately, there is a very high chance that there is little to no correlation based on a pure pH measurement.  The solubility and retention of Ammonia greatly depends on temperature, concentration of ammonia in the air phase, types of contaminants in the water (salts, emulsifiers, treating chemistry, corrosion products etc.).  Agitation also is a factor (more agitation causes more ammonia to be removed from the solution).

I wish you the best with your calculation.

Sincerely,

Eugene

I like how you use simplified terms to describe solutions to problems that are easy and clear to understand without sacrificing any relevant knowledge.

So by your answer it would seem any type of formula would need to account for numerous factors that in most common laboratories would be impractical to execute unless a good share of the factors were set as a constant?


I have seen similar fluctuations in some of my early experiments involving NaOh with regards to temperature and agitation and most of all time.

[eugenedakin]

Hello C6H8O7,

Good question!

So by your answer it would seem any type of formula would need to account for numerous factors that in most common laboratories would be impractical to execute unless a good share of the factors were set as a constant?

Yes, you can either: 1) take into account the numerous factors, or 2) keep the above factors constant and measure the rate of ammonia evolution 

Good thinking!

Sincerely,

Eugene