ABSTRACT
The amount of chlorine added is called the dosage. It is common to hear that “X" number of pounds of chlorine were dosed on a given day to the plant diluent. Much of this chlorine is used up. It’s used to kill some of the bugs. It’s also used up in reactions with the leftover food in the effluent. Either way, a lot of the chlorine that is put into the water gets used up. The amount of chlorine that gets used up is called the chlorine demand. The demand is the amount of chlorine that gets used up when the chlorine is added to the plant effluent. The amount of chlorine that is still left in the water is called the chlorine residual. The chlorine residual is the chlorine left after the chlorine demand has been satisfied.
