Chloramine

[Randy Holmes-Farley]

I'm not sure what you are saying or why you are worrying over this? Why do you think that ammonia is "burning" DI resins?

Those of us using normal RO/DI systems do not detect chloramine and only find substantial ammonia when the DI depletes.

Bear in mind that what you posted is a sales brochure from 15 years ago from a company that sells carbon for dialysis applications.

 

[slow_leak]

I am depleting DI resins every 3-4 months since city switched to chloramine.

I was roughly showing contact time is much greater with larger carbon housings, allowing for the preferred reaction. Brochure was of interest because it indicated how activity of catalytic carbon is measured. I am sure that has not changed much. I was also indicating 2 - 10" carbon housings is not of much value increasing contact time.

4 resin cartridges a year will be a near wash with up front cost of larger carbon chamber.

 

[Randy Holmes-Farley]

How much water is 3-4 months and what is the TDS of the incoming water?

I wouldn't assume that ammonia is the primary culprit on the DI depletion. I'm certain it is not in mine since the post RO water has TDS around 5-9 ppm in my system, and that certainly is not mostly ammonia.

 

[slow_leak]

I use a lot of water for 75 gpd system.

I am leaning towards using two DI cartridges, since refills are cheap. Water TDS has not changed much in my area.

 

[Randy Holmes-Farley]

OK, but I'll just point out that even if all of the ammonia from all of the chloramine got to the DI (and it won't, since the RO membrane will reject most of it), it represents a small number of ions. I expect that less than the equivalent of 1 ppm TDS is coming from chloramine ammonia in typical systems.

 

[bertoni]

I went through a local shift to chloramine and never noticed any difference in my RO/DI at all, although my area did have low TDS (40-50 ppm) tap water.

 

[drummereef]

Randy, how does this fare for drinking water systems that do not have a DI stage? Should chloramine specific carbon filters be used to reduce/eliminate ammonia that could possibly getting past the RO membrane into the drinking water?

 

[Randy Holmes-Farley]

I do not know if such systems pass ammonia out or not. A trace of ammonia is not a tox concern for people.

From the FDA:

The FDA (1973) determined that concentrations of ammonia and ammonium compounds normally present in food do not suggest a health risk; ammonia and ammonium ions are recognized to be integral components of normal metabolic processes. However, some restrictions have been placed on levels of ammonium salts allowable in processed of foods. Maximum allowable levels in processed foods are as follows: 0.04–3.2% ammonium bicarbonate in baked goods, grain, snack, foods and reconstituted vegetables; 2.0% ammonium carbonate in baked goods, gelatins and puddings; 0.001% ammonium chloride in baked goods and 0.8% in condiments and relishes; 0.6–0.8% ammonium hydroxide in baked goods, cheeses, gelatins and puddings; 0.01% monobasic ammonium phosphate in baked goods; and 1.1% dibasic ammonium phosphate in baked goods, 0.003% in nonalcoholic beverages, and 0.012% for condiments and relishes.

 

[Ron Reefman]

OK, now I'm getting confused. Does the 'tds creep' issue happen all the time the RO/DI system is turned off, i.e. the DI is being affected even without RO water moving thru it? Or is it that the 'tds creep' happens at the RO membrane and is then pushed thru the DI when it's turned on again?

I have a 'T' between my RO and DI with shutoff valves going to the DI and to a 'by pass' drain. I close both after using the RO/DI system to make water. When I want to start making water again I open the 'by pass' valve for a couple of minutes while I do a flush of the RO system and for the first minute or two of RO production. Then I open the DI valve and close the by pass valve. Isn't that a typical RO/DI procedure? Doesn't that minimize/eliminate the tds creep issues?

 

[Randy Holmes-Farley]

Yes, TDS creep happens any time the flow stops.

It happens when ions just upstream of the RO membrane have lots of time to slowly diffuse across. So ions get across it slowly, and then the TDS on the downstream side of the membrane rises. Eventually, the TDS will be the same on both sides of the membrane, and that burst of ions when you first turn it back on will help deplete the DI resins.

Your system will reduce or eliminate creep issues, but many setups do not do that. Mine has no such flush system. How important that is may depend on the TDS of the incoming tap water.

 

[drummereef]

I do not know if such systems pass ammonia out or not. A trace of ammonia is not a tox concern for people.

From the FDA:

The FDA (1973) determined that concentrations of ammonia and ammonium compounds normally present in food do not suggest a health risk; ammonia and ammonium ions are recognized to be integral components of normal metabolic processes. However, some restrictions have been placed on levels of ammonium salts allowable in processed of foods. Maximum allowable levels in processed foods are as follows: 0.04–3.2% ammonium bicarbonate in baked goods, grain, snack, foods and reconstituted vegetables; 2.0% ammonium carbonate in baked goods, gelatins and puddings; 0.001% ammonium chloride in baked goods and 0.8% in condiments and relishes; 0.6–0.8% ammonium hydroxide in baked goods, cheeses, gelatins and puddings; 0.01% monobasic ammonium phosphate in baked goods; and 1.1% dibasic ammonium phosphate in baked goods, 0.003% in nonalcoholic beverages, and 0.012% for condiments and relishes.

Thanks Randy! I guess that's if you believe the FDA is telling the truth... or not. :lol:

 

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing.