DOI: https://doi.org/10.55373/mjchem.v24i2.12

Keywords: Eggshell membrane; waste palm cooking oil; free fatty acids; Alizarin Red

Abstract

Eggshell membrane (ESM) was functionalized with waste palm cooking oil (WPCO) and used as an adsorbent (ESM@WPCO) for the removal of toxic Alizarin Red dye from aqueous solutions. SEM analysis of ESM@WPCO revealed a large microporous network of interwoven and coalescing shell membrane fibres. FTIR analysis confirmed the attachment of free fatty acids onto the surface of ESM. The protocol for Alizarin Red removal using ESM@WPCO was optimized for pH, adsorbent dosage, contact time and initial concentration. A maximum removal rate of 93% was achieved at pH 2, with an adsorbent dosage of 20 mg for 50 mg L-1 Alizarin Red, and a treatment time of 40 min. The adsorption isotherms were also analysed using Langmuir and Freundlich models, and it was found that the Freundlich model was better in describing the adsorption isotherm process, with an R2 value of 0.98. From this model, a maximum adsorption capacity (Kf) value of 8.41 mg g-1 was obtained. The adsorption kinetics followed a pseudo-second order model with an R2 value of 0.99. The results also revealed that ESM@WPCO was an effective adsorbent for the removal of Alizarin Red from aqueous solutions.