Experimental Investigation and Kinetic Modeling of p‐Nitrophenol and Phenol by Kissiris‐Immobilized Ralstonia eutropha in a Batch Reactor

Co‐metabolic degradation of p ‐nitrophenol (PNP) and phenol by kissiris‐immobilized Ralstonia eutropha cells was studied in a batch bioreactor operated in recycling mode (30°C, initial pH of 7.7, aeration rate of 0.5 vvm, and recycling flow rate of 25 mL min −1 ). Decreasing trends of specific degradation rates of phenol ( q Sg ) and PNP ( q Sng ) with an increase of initial PNP concentration, were mathematically modeled considering the competitive inhibition between growth and non‐growth substrates and self‐inhibition of non‐growth substrate. A non‐linear regression on the equations used in defining of q Sg , and q Sng , was used to estimate the relevant kinetic parameters. On the best fitted curve, the kinetic parameters were q max Sg = 0.032 g Phenol g Cell −1 h −1 , K m Sg = 442.9 mg L −1 , q max Sng = 0.0056 g Phenol g Cell −1 h −1 , K m Sng = 181.2 mg L −1 , and K Sng = 0.489 mg L −1 . These parameters were used for dynamic prediction of the substrates concentration feature during co‐metabolic degradation experiments.