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A municipal wastewater treatment plant is designed for carbonaceous BOD (cBOD) removal and nitrification. The wastewater

Posted: Mon May 16, 2022 2:13 pm
by answerhappygod
A municipal wastewater treatment plant is designed for
carbonaceous BOD (cBOD) removal and nitrification. The wastewater
characteristics and kinetic coefficients are described in the table
below. The aeration tank DO concentration is 2.0 mg/L and MLVSS
concentration is 2500 mg/L. The temperature is 15°C. Assume that
the concentration of influent NH4-N that is nitrified accounts for
80% of influent TKN. Calculate the following parameters as a
function of SRT (i.e., derive mathematical expressions of the
following parameters as a function of SRT, respectively, and show
your calculation in detailed steps), and plot them as a function of
SRT by varying SRT from 3 to 20 days with 1 day interval. The
parameters to plot are:
(a) Effluent cBOD concentration (mg/L).
(b) Effluent NH4-N concentration (mg/L).
(c) Aeration tank volume (m3).
(d) Hydraulic retention time, Θ (hours).
(e) Total solids production as kg TSS/d (assume Xe = 0 mg/L and
VSS/TSS = 0.75).
(f) Oxygen requirement as kg/d.
Wastewater characteristics
Flow rate = 20,000 m3 /d
cBOD = 352 mg/L
TKN = 40 mg/L
Temperature = 15°C
Kinetic coefficients of heterotrophic bacteria at
20°C
µm=6 g VSS/g VSS∙d
θ
for µm = 1.07
Ks=20 mg cBOD/L
θ
for Ks = 1.00
Y=0.4 g VSS/g VSS
θ
for kd =1.04
Kd=0.12 g VSS/g VSS∙d
Kinetic coefficients of nitrification at
20°C
µnm=0.75 g VSS/g VSS∙d
θ for µn,m =1.07
Kn=0.74 mg NH4-N/L
θ for Ks,n=1.053
Yn=0.12 g VSS/g NH4-N
θ for kd,n =1.04
Kd,n=0.08 g VSS/g VSS∙d
θ for Ko = 1.00
Ko=0.5 mg O2/L
Please solve the e and f part