Hydrothermal carbonization of rambutan peel (<i>Nephelium lappaceum L.</i>) as a Green and low-cost adsorbent for Fe(II) removal from aqueous solutions
N. Normah, Novie Juleanti, Neza Rahayu Palapa, Tarmizi Taher, Pintauli Mariani Siregar, Alfan Wijaya, Aldes Lesbani
Abstract
This study aims to utilise rambutan peel waste and convert it into hydrochar then applied as an adsorbent to remove Fe(II) contaminants from aqueous solutions. Rambutan peel hydrochar (RP-HC) was prepared by hydrothermal treatment of raw RP at 200 °C. The prepared samples were characterised using XRD, FT-IR, BET, and SEM. The sample contains a lot of -NH and -OH active sites which will affect the performance of crude RP-HC and RP as adsorbents for the removal of Fe(II) from aqueous solutions. The results of the adsorption study showed that the adsorption of Fe(II) using RP-HC had a maximum adsorption capacity of 25.126 mg/L, while the RP was 14.553 mg/L and the adsorbent regeneration study showed that the adsorption effectiveness of RP and RP-HC was stable until the third cycle.