Chlorine is used for primary disinfection at a water treatment plant that treats
ID: 477094 • Letter: C
Question
Chlorine is used for primary disinfection at a water treatment plant that treats 0.2 m^3 s^-1 of reservoir water. Giardia (a protozoan) is the primary pathogen of concern, and the Giardia inactivation rate constant for free chlorine disinfection is 0.53 min^-1. The plant achieves 3-log removal (i.e., three orders of magnitude such that C_out = 0.001*C_in where C_l is number of Giardia cells per liter) of Giardia at pH 6.0 - 9.0 in a well-mixed chlorine contact chamber. What is the volume of the contact chamber? What total volume of contact chamber would be needed if chlorine treatment were constructed as five separate CMFR chambers in series? The volume reported should be the total volume of all five separate chambers.Explanation / Answer
mole balance:v0*CA0-v0*CA-rAV=0
The v0 is the volumetric flow rate , V is the volume of the reactor
v0*CA0-v0*CA=kCAV
CA0-CA=(kCAV)/v0
CA0-0.001CA0=(0.53*0.001CA0*V)/0.2
1-0.001=0.00265 V
volume of the reactor is 376.98 m3