Phenol removal from aqueous solution by activated carbon produced from avocado kernel seeds

Activated carbon derived from avocado kernels (AAC) was evaluated for its ability to remove phenol. The Brunauer–Emmett–Teller (BET) surface area of the AAC was 206 m2 g−1 and the total pore volume was 0.100 cm3 g−1. The kinetic of the adsorption process was described by a pseudo-second-order rate model. The maximum uptake was obtained at pH values between 4 and 8.5. The optimum adsorbent dose obtained was 0.1 g. The thermodynamic parameters exhibited the feasibility and the spontaneous nature of the adsorption process. Adsorption isotherms showed that the interaction of phenol with AAC surface was described by a localized monolayer adsorption. The adsorption mechanism was discussed based on experimental results, and the π–π interactions were considered to be an important parameter in the adsorption process. The adsorbent regeneration was investigated using several types of desorbing agents, but no agent show any promising result. The results showed that the prepared activated carbon was an effective adsorbent for phenol removal from aqueous solution.

► Avocado kernel seeds activated carbon (AAC) was used as adsorbent.
► The maximum adsorption capacity of phenol on AAC is 90 mg g−1.
► The negative ΔG° indicated that the adsorption was a spontaneous process.
► The π−π interactions is an important parameter in the adsorption process.