Combined Chloramines---- where do they go

[Ed Buell]

If I understand this right, combined chloramines are created when the chlorine we add to the pool
actually react with something in the pool and the resultant is a dead something and the chloramines.

I also think I understand that the chloramines are what causes the "chlorine smell" and irritating
situation in the pool.

I'm seeing none in my tests and am thankful for that.

Where do the chloramines go....i.e. how are they removed from the pool.


Thanks again for you help.

reporting here from south west Florida

 

[JasonLion]

Combined chlorine reacts with a second chlorine to break things down further. Depending on what is being broken down it takes a total of two or more chlorines before it is broken down to something non-organic.

The initial reaction, where the first chlorine binds to form a combined chlorine happens more quickly than the subsequent reactions. Sometimes that results in measurable CC levels, especially if you run out of chlorine before things run to completion.

 

[duraleigh]

Great answer, JasonLion. I learned from it as well.

 

[jblizzle]

The sun also breaks down the CC, correct? It is not only the chlorine that lowers the CC levels.

 

[Smykowski]

Yes. Tapatalk's search functions is no bueno, so I can't reference it myself, but chemgeek has done lots of posts on this.

Also why indoor pools have to be treated a little different then outdoor pools....no sunlight to do its thing.

 

[pooladdict]

Excellent work guys, really like how once attacked, more chlorine is needed to get rid of it. Is that the oxidization we all talk about?

 

[JasonLion]

Yes, this oxidation.

 

[chem geek]

Chlorine reacts very quickly with ammonia to produce monochloramine which is a Combined Chlorine (CC). As Jason noted, further reaction with additional chlorine that takes place more slowly ultimately results mostly in nitrogen gas (or some nitrate) and chloride salt. The formation of CC is not oxidation, but the further reaction with chlorine to produce the end products is oxidation.

There's also chlorine reacting with nitrogenous organics such as urea, but the principle is basically the same where CC is formed and then further reaction with chlorine oxidizes it to final products.

The UV in sunlight can react with some types of CC (mostly dichloramine) to break it down. The UV in sunlight also breaks down chlorine and when it does it produces hydroxyl radicals that are powerful oxidizers that can oxidize some bather waste that chlorine doesn't handle that well on its own.

 

[Ed Buell]

thanks for the answers. The entirety of the chemical reactions contained in a pool is very interesting.

Thankfully with the help of all of you TFP folks, my pool has worked great ever since we bought the house last november. My pool contractor apparently
has done a good job while we are up north.

It took a little to convince him to use the liquid chlorine only in the pool, but since I have gotten the CYA down to a reasonable level, all seems well.