Synthesis of pectin/Fe ₂ O ₃ membrane from Pomelo peel for removal of Brilliant Green and Crystal Violet

This study successfully synthesized a pectin/Fe 2 O 3 membrane from the Da Xanh grapefruit peel. In this case, Fe 2 O 3 was synthesized using a green solvent, and pectin was synthesized from grapefruit peel. Results from the structural analysis methods of SEM, EDX, XRD, FTIR, and BET showed the Fe 2 O 3 material to be a hexagonal shape. The pectin/Fe 2 O 3 material had tiny holes attached to the surface, and the cut surface shows the membrane to be close-knit fibers. The elemental composition of material was determined through EDX and FTIR spectrum which indicated the connection between the components in the film. The best adsorption capacity of BG (27.792 mg g −1 ) and CV (23.433 mg g −1 ) dyes were evaluated at the best conditions: 4 g L −1 , temperature 50 °C, pH 5 for BG and pH 4 for CV, 120 min and concentration 150 mg L −1 . The adsorption process of the material occurred following the PSO model, according to the mechanism of chemical bonding and interaction with each other. The adsorption isotherm occurred in the D–R model with BG and the Langmuir model with CV, both of which were monolayer adsorption with CV as a homogeneous surface and with BG as a heterogeneous surface. Therefore, the pectin/Fe 2 O 3 membrane material synthesized by the green chemistry method was a potential material from pomelo peel waste that can replace other adsorbent materials and save costs.