An effluent at a flow rate of 2670 m /d from a sewage treatment plant is to be disinfected. The laboratory data of disinfection studies with a chlorine dosage of 15 mg/l yield the model Nt = No e 0.145t where Nt = number of microorganisms surviving at time t (in min.) and No = number of micro-organisms present initially (at t = 0). The volume of disinfection unit (in m ) required to achieve a 98% kill of micro-organisms is _______

An effluent at a flow rate of 2670 m /d from a sewage treatment plant

1.	An effluent at a flow rate of 2670 m /d from a sewage treatment plant is to be disinfected. The laboratory data of disinfection studies with a chlorine dosage of 15 mg/l yield the model Nt = No e 0.145t where Nt = number of microorganisms surviving at time t (in min.) and No = number of micro-organisms present initially (at t = 0). The volume of disinfection unit (in m ) required to achieve a 98% kill of micro-organisms is _______
A.	55 m
B.	52 m
C.	53 m
D.	50 m
Answer» E.

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