A new approach to evaluate kinetic parameters and mass transfer coefficient in continuous stirred tank reactors.Application to antibiotic separation

Abstract

A method is proposed to evaluate kinetic parameters and mass transfer cofficients for adsorption processes carried out in continuous stirred tank reactors.This method,employing a biphasic model,does not linerize nonliner solute concertration versus time data not does it assume the assistence of equilibrum in a typical nonquilibrum situation as is currently done.For a nonlinear adsorption isotherm the coupled differiental equation need to be solved numerically,but using an elegent analytical solution it ia possible determine rate constant and mass transfer coefficient in the case of nonlinear kinetic with a linear adsorption isotherm.This solution(bihasic model linear ishorum)is obtaind and compared with solutions incorporating(i)a linear model(linear isthorm)and(ii)a numircal solution(non linear isthorm)for recovery of the antibiotic novobiotic and stirred tank reactors.For novobiocin adsortion versus time data,use of the biphasic model results in a lower presentage error than either the linear model or the numerical simlution;futher,it provides a far superior the of short time adsorption behavior.Hence we strongly advocate that the biphasic model be routinely employed along with linear model and numerical simlution of langmuir/friundich isotherms for intepretion of adsorption data