INVESTIGATION OF THE COMBINED EFFECTS OF EXTERNAL MASS-TRANSFER AND BIODEGRADATION RATES ON PHENOL REMOVAL USING IMMOBILIZED P-PUTIDA IN A PACKED-BED COLUMN REACTOR

A quantitative analysis of external mass transfer combined with a biod egradation reaction and correlation of the experiment with theory was performed for phenol removal using calcium-alginate gel-immobilized P. putida in a packed-bed column reactor Assuming first-order biodegrada tion kinetics, pseudo first-order biodegradation rate constants (k(p)) were calculated. To investigate the effect of external film diffusion on the biodegradation rate, various mass transfer correlation models of the type j(D) = KNRe-(l-n) were systematically tested and the mass transfer coefficients (k(m)) were calculated as a function of the mass flux (G) and the Reynolds number (N-Re) at different n values. The in trinsic first-order biodegradation rate constants (k) and the surface areas per unit weight of dried cells for mass transfer (A(m)) were det ermined from 1/k(p) vs. I/G(n) plots at the same n values. Finally, co mbining the k values with k(m)A(m) values, the pseudo first-order biod egradation rate constants (k(p)) were calculated again and compared wi th the k(p) values determined from experimental data; thus, it was dec ided that the mass transfer correlation j(D) = 1.625 Re-0.507 accurate ly predicted our experimental data. (C) 1998 Elsevier Science Inc.