Thermodynamics, kinetics, and adsorption properties of biomolecules onto carbon-based materials obtained from food wastes

Abstract

In this research, adsorption of Candida rugosa lipase enzyme (CRLE) onto activated carbon obtained from apple bark was carried out, and the thermodynamic parameters of adsorption process were investigated. The surface structural change of lipase enzyme and activated carbon was studied. The thermodynamic functions such as enthalpy, entropy, Gibbs free energy, and activation energy were investigated in their experimental work. The thermodynamic parameters of Delta G*, Ea, Delta H*, and Delta S* were calculated as - 75.56, 13.42, - 15.29 kJ mol(-1), and 202.2 J mol(-1) K-1 for CRLE adsorption, respectively. The experiment results showed that the adsorption process of CRLE on activated carbon is spontaneous and exothermic. The maximum adsorption capacity according to CRLE was 5.5 pH. The maximum adsorption capacity of active carbon was found to be 96.2 mg/g at pH 5.5, 309.5 K, and initial enzyme concentration of 5.0 x 10(-3) M. The protein molecules at this point are very stable that is close to the isoelectric point of lipase enzyme. As a result, we can say that the activated carbon can be used as an effective adsorbent for the adsorption of CRLE.