Adsorptive Separation of Lysozyme from Aqueous Solutions Using Sulphonyl and Carboxyl Functionalized Stearyl Alcohol Grafted Epichlorohydrin

In the present work ability of the two novel adsorbents, sulphonyl and carboxyl functionalized stearyl alcohol-grafted epichlorohydrin, SA-g-E-SO₃H, SA-g-E-COOH; to remove lysozyme (LYZ) from aqueous solution was assessed. The adsorbent characterization was done using FTIR, XRD, SEM and TGA analyses. The adsorption efficiency was influenced by solution pH and the optimum operating pH was found to be 4.0 for SA-g-E-SO₃H and 5.0 for SA-g-E-COOH and their adsorption efficiency was evaluated using the various isotherm and kinetics models. The Sips isotherm model and pseudo-second-order kinetic model were found to be the best for describing the equilibrium and kinetic behaviors of the adsorption process. Batch adsorption/desorption studies in acidic medium, for over six cycles showed excellent regeneration capability of the adsorbents and could lead to the development of viable and promising technology for the adsorptive recovery of LYZ from aqueous solutions. The efficiency of the adsorbents for the LYZ adsorption was verified using egg white. The result obtained from this study revealed that adsorption ability of 25 mg of SA-g-E-COOH is 98.4 % which is more than that of SA-g-E-SO₃H (96.2 %). The efficiency of SA-g-E-SO₃H to remove LYZ from aqueous solution was found to be higher compared to SA-g-E-COOH.