Continuous Cultivation - Bioprocess Engineering: Kinetics, Biosystems, Sustainability and Reactor Design - page 657

TABLE P12.19

Time, h X , g/L P , g/L

0 0.3 < 0.01

<

3 1.0 0.01

6 2.3 < 0.01

8 4.0 0.010

9 5.1 0.025

10 6.5 0.060

10.5 7.0

11 7.4 0.10

12 7.7 0.17

13 7.8 0.26

14 0.36

15 8.0 0.47

16 8.0 0.54

17 0.58

18 0.60

1m 3 /h with substrate at 2000 mg/L is treated in an
upflow packed bed containing immobilized bacteria in the form of biofilm on small
ceramic particles. The effluent substrate level is desired to be 30 mg/L. The rate of
substrate removal is given by the following equation:
r S ¼ r max XS

12.20. A wastewater stream of Q ¼

K S þ S
The particles are very small and the immobilized bacteria are of a very thin film and
thus the effectiveness factor can be considered to be 100%. By using the following infor-
mation, determine the required height of the column ( H ) for a bed diameter of 2 m.

h 1 m 2 ; K S ¼ 200 m 2 = m 3 r max ¼ 0:5 ; X ¼ 0:1 g = mg = L ; a ¼ 100

12.21. Table P12.21 shows data for the production of a secondary metabolite from a small-
scale batch reactor. There is a stream of substrate available at 250 L/h of the same
medium as that generating the batch fermentation data. Assume that two reactors,
each with 2000-L working volume, are available. You will use exactly the same culture
conditions (medium, pH, temperature, and so on) as in the batch reactor.
(a) Determine the outlet concentration of the product.
(b) Compare that obtained in part (a) to the value predicted if a single 4000-L reactor
was used.