Disinfection and Sanitizers Flashcards

Chloramines (combined chlorine) are formed when free chlorine reacts with:

Answer: Nitrogen-containing compounds such as urine, sweat, and ammonia

Chlorine combines with nitrogen-containing bather waste (urine, perspiration, body oils) to form chloramines.

High combined chlorine (chloramine) levels in pool water typically cause:

Answer: Eye irritation, skin irritation, and a strong 'chlorine' odor

Chloramines, not free chlorine, are responsible for the characteristic pool smell, red eyes, and skin irritation experienced by swimmers.

Breakpoint chlorination is defined as:

Answer: Adding sufficient chlorine to oxidize and destroy all combined chlorine, leaving a free residual

Breakpoint chlorination is the process of adding enough chlorine (roughly 10× the combined chlorine level) to destroy all chloramines and establish a free chlorine residual.

To reach breakpoint and destroy combined chlorine, you must add approximately how much chlorine relative to the combined chlorine reading?

Answer: 7.6 to 10 times the combined chlorine level

Breakpoint requires adding chlorine at approximately 7.6–10 times the combined chlorine concentration to fully oxidize the chloramines.

How is total chlorine calculated?

Answer: Free chlorine plus combined chlorine

Total chlorine = free chlorine + combined chlorine; it represents all chlorine species present in the water.

Under the Model Aquatic Health Code, what combined chlorine (chloramine) level should trigger corrective action such as superchlorination?

Answer: Greater than 0.4 ppm

The MAHC requires pools to take corrective action (superchlorinate or close) when combined chlorine exceeds 0.4 ppm.

Superchlorination (shock treatment) is most appropriately performed:

Answer: After heavy use, when combined chlorine is elevated, or as a routine weekly treatment

Shock is used to destroy accumulated chloramines after heavy use, and as a preventive weekly maintenance measure to maintain water quality.