Sodium hypochlorite (NaOCl, available at a strength of 14%) is used as a disinfectant at a water treatment plant that processes 25 mgd of water. When added to water, sodium hypochlorite undergoes the reactions shown below. The facility would like to achieve an initial hypochlorite dose of 4.5 mg/L OCl- and will disinfect the water pH=7.0. The disinfection chamber will have a L:W:D ratio of 60:1:1.

Reaction #1: NaOCl-> Na+ OCl- no pKa...reaction proceeds to

completion

Reaction #2: HOCl -> H+ + OCl- pKa = 7.6

a. Based on Reaction #1, how much NaOCl (in gal/min) will be required to achieve the target dose?