Facile synthesis of metal incorporated chitin for the recovery of oil from oil-in-water emulsion using adsorptive method

Abstract

This work describes the removal of oil from oily wastewater using the metal entrapped biopolymer such as lanthanum modified chitin (La-Ct) and zirconium modified chitin (Zr-Ct) investigated by batch adsorption studies. Various parameters viz., contact time, pH, sorbent dosage, initial oil concentration and temperature on the oil removal capacity were optimized. The characterizations of all the sorbents were done using FTIR, SEM with EDAX, XRD, TGA and contact angle measurement. At room temperature, both metal modified sorbents showed higher oil removal capacity than chitin (Ct). The maximum oil removal percentage of 27, 69 and 82% were obtained using 12 g L−1 of Ct, La-Ct and Zr-Ct respectively at pH 3 with 4% initial oil concentration. The pH of the sorption studies revealed that oil sorption was favored in acidic condition. The four isotherm models namely Freundlich, Langmuir, Dubinin–Radushkevich and Tempkin were applied to examine the isotherm behavior. Langmuir isotherm was fitted well with the experimental data. Thermodynamic studies revealed that adsorption process is endothermic and spontaneous in nature. This present work provides a potential platform for the expansion of oil sorption studies.