Improvement of anionic and cationic dyes removal in aqueous solution by Indonesian agro-waste oil palm empty fruit bunches through silylation approach

Abstract

In this study, oil palm empty fruit bunch (OPEFB) waste has been successfully utilized and chemically pretreated as a powerful adsorbent for removing anionic and cationic dyes in aqueous media. The extracted- and silylated-OPEFB, denoted as tOPEFB and s-OPEFB respectively, were prepared and morphologically, chemically and physically characterized using TEM, FTIR, XRD, BET, and TGA. The tOPEFB was contained α-cellulose confirmed by FTIR and XRD. This material has good adsorption toward methylene blue, having adsorption capacity (Qm) of 192.31 mg g−1, but it was weak to adsorb procion red dye (Qm = 20.70 mg g−1). Surface modification of tOPEFB not only provided a new amine functional group as indicated by FTIR analysis, but also improved the BET surface area of material up to 30.53%. As results, a high Qm of s-OPEFB was achieved toward procion red (Qm = 208.33 mg g−1) and methylene blue (Qm = 149.25 mg g−1). It confirmed that the surface engineering by silylation approach offered a positive impact on material properties, which directly improved their adsorption performance toward both anionic and cationic dyes.