Efficient oil removal from water using carbonized rambutan peel: Isotherm and kinetic studies

Tóm tắt

The study aims to assess the diesel oil adsorption capacity of activated carbon derived from rambutan peel, a prevalent agricultural by-product in Vietnam. The adsorption process will be investigated using various adsorption isotherms (Langmuir, Freundlich, Temkin, Dubin-Radushkevich), adsorption kinetics (pseudo-first order and pseudo-second order). The characterization analysis of RPAC revealed the following values: BET surface area of 786.0143 m2/g, BJH adsorption cumulative volume of pores at 0.05392 cm3/g, and BJH adsorption average pore diameter of 55.2432 nm. Individual assessments of factors influencing oil removal efficiency and adsorption capacity identified the optimal initial oil concentration at 1% volume/volume, an optimum contact time of 60 minutes, and an equilibrium adsorption time of 80 minutes. The optimal adsorbent dosage was 250 mg, and the ideal pH was 6. The adsorption process adhered to the Langmuir isotherm with an R² value of 0.9993, yielding a maximum adsorption capacity of 5,712.0 mg/g. The pseudo-second-order model provided a better fit for RPAC’s oil adsorption process with an R² value of 0.9969.