I owe a couple of users here a apology you know who you are ,I recently stated in a thread on water changes that chloramine did not dissolve when airated but on further research i have found out this statement is incorrect so I've added some interesting info i found published by the San Frisco Publics Utilites commision:
Q 16: How much time will it take for both chloramine and chlorine to dissipate and at what ppm level? Can chloramine and/or ammonia be boiled out of water or dissipated by letting the water sit?
A: While both chlorine and chloramine residuals decrease with time. chloramine takes longer than free chlorine. The chloramine decomposition rate is also affected by the exposure to air and sunlight. Chloramine and ammonia, like chlorine, will eventually dissipate completely over time but it is not practical to let the water sit for these to dissipate. Unlike chlorine, which only takes a few days to dissipate when left to stand, chloramine may stay in water for a few weeks (SFPUC) and ammonia remains in the water even longer. It usually takes days for chloramine to be dissipated when exposed to air and sunlight.
Boiling the water will remove chlorine but it will take much longer to remove chloramine. There are chemicals available that quickly and effectively remove chloramine.
Q 17: Can charcoal filters remove ammonia?
A: Charcoal or granular activated carbon (GAC) treatment can reduce chloramine concentrations of 1 to 2 mg/L to less than 0.1 mg/L. GAC treatment may result in ammonia, chloride, and nitrogen gas as by-products of the adsorption process of chloramine and reaction with the carbon surface. The by-product concentrations will be low (e.g., less than 0.5 mg/L ammonia as nitrogen). However, it may be desirable to remove these by-products depending on water use (CDM, 2003).
To remove the low levels of chloramine by-products, GAC treatment should be followed by a reverse osmosis (RO) process. RO should not be used alone as the chloramine residual can damage the RO membrane elements. GAC treatment will remove the chloramine residual allowing RO to effectively remove portions of the other constituents. Owners of home RO units should contact the manufacturer of their units to determine if a GAC unit is installed upstream of the RO system.
GAC filters can also remove ammonia but nitrifying bacteria must establish themselves in the GAC column before ammonia removal can occur. Such an application would need to be followed by disinfection step with either a small RO unit or a UV lamp.
Q 16: How much time will it take for both chloramine and chlorine to dissipate and at what ppm level? Can chloramine and/or ammonia be boiled out of water or dissipated by letting the water sit?
A: While both chlorine and chloramine residuals decrease with time. chloramine takes longer than free chlorine. The chloramine decomposition rate is also affected by the exposure to air and sunlight. Chloramine and ammonia, like chlorine, will eventually dissipate completely over time but it is not practical to let the water sit for these to dissipate. Unlike chlorine, which only takes a few days to dissipate when left to stand, chloramine may stay in water for a few weeks (SFPUC) and ammonia remains in the water even longer. It usually takes days for chloramine to be dissipated when exposed to air and sunlight.
Boiling the water will remove chlorine but it will take much longer to remove chloramine. There are chemicals available that quickly and effectively remove chloramine.
Q 17: Can charcoal filters remove ammonia?
A: Charcoal or granular activated carbon (GAC) treatment can reduce chloramine concentrations of 1 to 2 mg/L to less than 0.1 mg/L. GAC treatment may result in ammonia, chloride, and nitrogen gas as by-products of the adsorption process of chloramine and reaction with the carbon surface. The by-product concentrations will be low (e.g., less than 0.5 mg/L ammonia as nitrogen). However, it may be desirable to remove these by-products depending on water use (CDM, 2003).
To remove the low levels of chloramine by-products, GAC treatment should be followed by a reverse osmosis (RO) process. RO should not be used alone as the chloramine residual can damage the RO membrane elements. GAC treatment will remove the chloramine residual allowing RO to effectively remove portions of the other constituents. Owners of home RO units should contact the manufacturer of their units to determine if a GAC unit is installed upstream of the RO system.
GAC filters can also remove ammonia but nitrifying bacteria must establish themselves in the GAC column before ammonia removal can occur. Such an application would need to be followed by disinfection step with either a small RO unit or a UV lamp.
