Facile preparation of a porous biochar derived from waste crab shell with high removal performance for diesel

Abstract

In this study, a porous biochar material derived from waste crab shell was prepared by one-step hydrothermal carbonization and acetic acid activation method at 180°C, which was characterized by SEM, BET, XRD and FTIR. The results show that the as-prepared crab shell biochar (CSB) exhibits a fluffy irregular layered structure with abundant pores and oxygen-containing functional groups, which can facilitate the adsorption of diesel using CSB. In addition, batch adsorption experiments had been performed, effects of initial diesel concentration, adsorption time, adsorbent dosage and pH on the diesel adsorption using CSB were analyzed, which could be observed that CSB has high removal efficiency for diesel, and the maximum removal rate is up to 80.1%. The adsorption isotherms and kinetic studies were also investigated to determine the adsorption mechanism of diesel using CSB, the results show that the Langmuir model and the pseudo-second-order model are more suitable for describing the adsorption of diesel using CSB, indicating that the adsorption of diesel oil by CSB is monolayer chemical adsorption. This study will provide a theoretical basis for the high-value utilization of waste crab shell, which has a great potential in the treatment of oil spill.