Question

11-1 Determine the inactivation rate constant for total coliform for one of the fol- lowing four treated effluents (sample to be selected by instruetor) assiming Chickis law efflue raturé was 2 Time, min Log of organisms remaining Sample 0.0 4.0 8.0 0.0 0.0 6 11.8 17.2 0.0 6 5 4 3 2 12 24 36 47.8 60.2 5 16.6 25.2 35 40 13 17 20 25 30.4 10 Combined chlorine residual, mg/L

Answer 1

At time t = 0 min rightarrow log(Nt) = 7 Nt = no. of micro organisms remained Nt = 1067 chicks law N_0 initial no. of organisms at t = 0 Nt = N_0 e^-kt At t = 0 = > 10^7 = N_0 e^-k (0) N_0 = 10^7 At t = 12 min = > log Nt = 6 Nt = 10^6 Nt = N_0 e^-kt 1066 1067 e^-k times 12 Inactivation rate constant = k = 0.192/min k = 11.5/hr