Biodegradation kinetics of ferrous(II) cyanide complex ions by immobilizedPseudomonas fluorescens in a packed bed column reactor

Combined external mass transfer and intrinsic biodegradation effects on the observed biodegradation rate were investigated for ferrous (II) cyanide co mplex (ferrocyanide) ions removal with calcium-alginate gel immobilized Pse udomonas fluorescens in a packed bed column reactor. Assuming first-order b iodegradation kinetics, observed first-order biodegradation rate constants (k(p)) were calculated at different flow rates. To investigate the effect o f external film diffusion on the observed biodegradation rate, several exte rnal mass transfer correlation models of the type J(D) = KNRe-(1-n) were te sted and the mass transfer coefficients (k(l)) were calculated as a functio n of the mass flux (G) and the Reynolds number (N-Re) at different K and n values. The intrinsic first-order biodegradation rate constants (k) and the surface areas per unit weight of dried cells for mass transfer (a(m)) were determined from ilk, versus 1/G(n) plots at the same n values. Combining t he k and k,a, values, the observed first-order biodegradation rate constant s (k(p)) were calculated again at the same n values and compared with the k , values determined from experimental data. The mass transfer correlation J (D) Science Ltd. All rights reserved.