#Question id: 14268
#SCPH05 I Biotechnology
An activated-sludge waste treatment system is required to reduce the amount of BOD5 from 1000 mg/l to 20 mg/l at the exit. The sedimentation unit concentrates biomass by a factor of 3. Kinetic parameters are µm = 0.2 h-1 , Ks = 80 mg/l, kd = 0.01 h-1 , and Y M X/S = 0.5 g MLVSS/g BOD5. The flow of waste water is 10000 l/h and the size of the treatment basin is 50,000 l. What is the value of the solids residence time?
#Question id: 14269
#SCPH05 I Biotechnology
An activated-sludge waste treatment system is required to
reduce the amount of BOD5 from 1000 mg/l to 20 mg/l at the exit. The
sedimentation unit concentrates biomass by a factor of 3. Kinetic parameters
are µm
= 0.2 h-1 , Ks = 80 mg/l, kd = 0.01 h-1 , and Y M X/S
= 0.5 g MLVSS/g BOD5. The flow of waste water is 10000 l/h and
the size of the treatme nt basin is 50,000 l. What value of the recycle ratio
must be used?
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#Question id: 14270
#SCPH05 I Biotechnology
Consider a well-mixed waste treatment system for a small-scale system. The system is operated with a reactor of 1000 l and flow rate of 100 l/h. The separator concentrates biomass by a factor of 2. The recycle ratio is 0.7. The kinetic parameters are µm = 0.5 h-1 , Ks = 0.2 g/l, Y M X/S = 0.5 g/g, and kd = 0.05 h-1 . What is the exit substrate concentration?
#Question id: 14271
#SCPH05 I Biotechnology
Penicillin is produced by P. chrysogenum in a fed-batch culture with the intermittent addition of glucose solution to the culture medium. The initial culture volume at quasi-steady state is V0 = 500 l, and glucose-containing nutrient solution is added with a flow rate of F = 50 l/h. Glucose concentration in the feed solution and initial cell concentration are S0 = 300 g/l and X0 = 20 g/l, respectively. The kinetic and yield coefficients of the organism are mm = 0.2 h-1 , KS = 0.5 g/l, and YX/S = 0.3 g dw/g glucose. Determine the concentration of cells at quasi-steady state when t = 10 h.
#Question id: 14272
#SCPH05 I Biotechnology
Penicillin is produced by P. chrysogenum in a fed-batch culture with the intermittent addition of glucose solution to the culture medium. The initial culture volume at quasi-steady state is V0 = 500 l, and glucose-containing nutrient solution is added with a flow rate of F = 50 l/h. Glucose concentration in the feed solution and initial cell concentration are S0 = 300 g/l and X0 = 20 g/l, respectively. The kinetic and yield coefficients of the organism are mm = 0.2 h-1 , KS = 0.5 g/l, and YX/S = 0.3 g dw/g glucose. If qP = 0.05 g product/g cells h and P0 = 0.1 g/l, determine the product concentration in the vessel at t = 10 h
#Question id: 14273
#SCPH05 I Biotechnology
Nicotiana tabacum cells are cultured to high density for
production of polysaccharide gum. The reactor used is a stirred tank,
containing initially 100 litres medium. The maximum specific growth rate of the
culture is 0.18 d-1 and the yield of biomass from substrate is 0.5 g
g-l. The concentration of growth-limiting substrate in the medium is
3% (w/v). The reactor is inoculated with 1.5 g l- 1 cells and
operated in batch until the substrate is virtually exhausted; medium flow is
then started at a rate of 4 l d-1. Fed-batch operation occurs under
quasi-steady-state conditions. Estimate the batch culture time. ____________________