Disinfection Flashcards
The addition of oxygen, removal of hydrogen, or the removal of electrons from an element or compound.
Oxidation
Any substance, such as base metal (iron) or the sulfide ion (S), that will readily donate (give up) electrons.
Reducing Agent
The total concentration of chlorine in water, including the combined chlorine (such as inorganic and organic chloramines) and the free available chlorine.
Total chlorine
Chlorine combined with other substances, mainly ammonia.
Combined chlorine residual
Organic substances (produced by living organisms) that cause or speed up chemical reactions. Organic catalysts or biochemical catalysts.
Enzymes
An aerobic process in which bacteria oxidize the ammonia and organic nitrogen in water into nitrite and then nitrate.
Nitrification
The concentration of chlorine present in water after the chlorine demand has been satisfied.
Residual chlorine
The cloudy appearance of water caused by the presence of suspended and colloidal matter.
Turbidity
Compounds formed by the reaction of hypochlorous acid (or aqueous chlorine) with ammonia.
Chloramines
What is not a type of physical disinfection?
a. Chlorine
b. Heat
c. Ultrasonic waves
d. Ultraviolet rays
Chlorine
What is not a chemical disinfectant?
a. Bromine
b. Carmine
c. Ozone
d. Sodium hydroxide
Carmine
What is a limitation of prechlorination?
a. May control algal and slime growths
b. May control mudball formation
c. May increase chlorine contact time
d. May increase the formation of THMs in raw water
May increase the formation of THMs in raw water
Why do you not use wrenches longer than
6 inches (15 cm), pipe wrenches, or wrenches with an extension to open chlorine container valves?
a. These wrenches are only available in metric sizes
b. These wrenches are too costly
c. These wrenches do not fit on chlorine container valves
d. You could exert too much force and break the valve
You could exert too much force and break the valve
What should be done to the water supply pump when the hypochlorinator is shut down?
a. Operate the water supply pump as usual
b. Start the pump slowly to ease into full operation
c. Turn water supply pump off
d. Turn water supply pump on at full operation
Turn water supply pump off
If consumers complain about chlorine tastes in their drinking water, what is the most likely cause of this problem?
a. The chlorine dose is inadequate
b. The chlorine dose is the wrong mix of chemicals
c. The chlorine dose is too high
d. The chlorine dose was added too late in the treatment process
The chlorine dose is inadequate
