Acid-modified adsorbents from sustainable green-based materials for crude oil removal

Abstract

This research was carried out to study the sorption capacity of crude oil using acidmodified green-based adsorbents originated from kenaf core and coconut shell. The adsorbent modification was impregnated in the lauric acid, phosphoric acid, and citric acid solution via the conventional method known as wetness impregnation technique. A comparison study of oil sorption capacity between acid-modified kenaf core and acid-modified coconut shell were conducted to identify a better adsorbent for crude oil adsorption. Variable Pressure Scanning Electron Microscopy (VPSEM) equipped with Energy Dispersive X-Ray Spectroscopy (EDX) were utilized to study the morphological characteristics and element compositions for both the unmodified and acid-modified adsorbents. Besides, Fourier Transform Infrared Spectroscopy (FTIR) was used to address the presence, absence, and/or shrink of certain functional groups for both unmodified and acid-modified adsorbents. Based on these three acids used, lauric acid was the best acid modifier than phosphoric acid and citric acid that performed the highest oil adsorption capacity. The VPSEM images of acid-modified adsorbents determined the presence of new pores and thinner walls across the hollow fibres compared to the unmodified adsorbent. Besides, FTIR results proved the presence of new peaks on the green-based adsorbents that confirmed the successful of acid impregnation procedure. This study have proposed that acid-modified greenbased adsorbents has high potential to tackle the issues of crude oil spillage. The higher adsorption performance of kenaf core than coconut shell demonstrates that kenaf core can be a low-cost and competitive adsorbent in various applications and expertises.