Additional Homework Problems

CDP7-EB

  Experiments showed [Biotech. Bioeng., 17, 1137 (1975)] that the denitrifying ability of the bacterium Micrococcus denitrificans was retained even after these bacteria were encapsulated in a liquid surfactant membrane. These immobilized cells created an emulsion when suspended in water; each drop was viewed as a "bag of enzymes" that followed simple Michaelis-Menten kinetics. The following laboratory batch reactor data were obtained on the denitrification of various aqueous solutions of nitrite ion, all containing the same volume fraction of cell emulsion (concentration of cells in emulsion was 50 mg of wet cells/ml of emulsion);
     
   

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    The aqueous effluent from Acme Chemical Co. contains 0.25 M nitrite ion. Management wishes to fill an available 500-ft3 concrete basin (modeled as a well-mixed batch reactor) with this effluent, and then subject it to denitrification with a similar volume fraction of emulsion containing a similar charge of cells as was done in the lab. If the cells remain active for only 68 h, will it be possible to reduce the nitrite level to 500 ppm? If not, what parameter could be changed to achieve this reduction? (J. Pochodylo, University of Michigan, 1983)


[2nd Ed. P12-18]