#Question id: 14313
#SCPH05 I Biotechnology
An industrial waste-water stream is fed to a stirred-tank
reactor continuously and the cells are recycled back to the reactor from the
bottom of the sedimentation tank placed after the reactor. The following are
given for the system: F = 100 l/h; S0 = 5000 mg/l; mm = 0.25 h-1 ; Ks = 200
mg/l; α (recycle ratio) = 0.6; C (cell
concentration factor) = 2; Y M X/S = 0.4. The effluent
concentration is desired to be 100 mg/l. Determine the cell concentration in the
reactor and in the recycle stream.
_____________
#Question id: 14314
#SCPH05 I Biotechnology
An industrial waste-water stream is fed to a stirred-tank
reactor continuously and the cells are recycled back to the reactor from the
bottom of the sedimentation tank placed after the reactor. The following are
given for the system: F = 100 l/h; S0 = 5000 mg/l; mm = 0.25 h^-1 ; Ks = 200
mg/l; α (recycle ratio) = 0.6; C (cell
concentration factor) = 2; Y M X/S = 0.4. The effluent
concentration is desired to be 100 mg/l. The effluent concentration is desired to be
100 mg/l. If the residence time is 2 h in the sedimentation tank, determine the
volume of the sedimentation tank and cell concentration in the effluent of the
sedimentation tank.
#Question id: 14314
#SCPH05 I Biotechnology
An industrial waste-water stream is fed to a stirred-tank
reactor continuously and the cells are recycled back to the reactor from the
bottom of the sedimentation tank placed after the reactor. The following are
given for the system: F = 100 l/h; S0 = 5000 mg/l; mm = 0.25 h^-1 ; Ks = 200
mg/l; α (recycle ratio) = 0.6; C (cell
concentration factor) = 2; Y M X/S = 0.4. The effluent
concentration is desired to be 100 mg/l. The effluent concentration is desired to be
100 mg/l. If the residence time is 2 h in the sedimentation tank, determine the
volume of the sedimentation tank and cell concentration in the effluent of the
sedimentation tank.
#Question id: 14329
#SCPH05 I Biotechnology
During exponential phase in batch culture, the growth rate of a culture is proportional to the concentration of cells present. When Streptococcus lactis bacteria are cultured in milk, the concentration of cells doubles in45 min. If this rate of growth is maintained for 12 h, what is the final concentration of cells relative to the inoculum level?
#Question id: 14330
#SCPH05 I Biotechnology
A radioactive isotope decays at a rate proportional to the
amount of isotope present. If the concentration of isotope is C (mg l-I),
its rate of decay is:
A solution of the isotope 32p is used to
radioactively label DNA for hybridisation studies. The half-life of 32p
is 14.3 days. According to institutional safety requirements, the solution
cannot be discarded until the activity is 1% its present value. How long will
this take?____________________
#Question id: 14331
#SCPH05 I Biotechnology
To ensure turbulent conditions and minimum mixing time during agitation with a turbine impeller, the Reynolds number must be at least 104. A stirred laboratory-scale fermenter with a turbine impeller 5 cm in diameter is operated at 800 rpm. If the density of broth being stirred is close to that of water, what is the upper limit for viscosity of the suspension if adequate mixing is to be maintained?