Equilibrium, kinetics, and thermodynamics study of phenol adsorption onto Phoenix dactylifera leaf adsorbents

Phenol is known to be toxic pollutant causing adverse impact on human health and environment. Thus, the present study aimed to remove the phenol from aqueous solutions utilising natural palm date natural leaf (NL) and palm date leaf chemically activated with H3PO4 activated carbon leaf (ACL). Brunauer-Emmett-Teller analysis, Fourier-transform infrared, X-ray diffraction, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy are techniques used to characterize the sorbents. The phenol removal capacity of NL and ACL was investigated in batch experiments taking phenol content (10-70 mg/L), time (15-240 min), pH (2-12), adsor-bent dose (0.1-0.6 g), and temperature (25 degrees C-65 degrees C). The maximum decontamination efficiencies of (42.4%) and (91.5%) on NL and ACL, respectively, were obtained at a pH of 6, temperature 25 degrees C and adsorbent dose of 0.4 g for each. The kinetic and equilibrium adsorption data of phenol fit well to the pseudo-second-order model and Temkin isotherm, respectively. Furthermore, the utmost phe-nol sorption capacity of 7.645 and 13.369 mg/g was attained for NL and ACL, respectively. The results of studied diffusion models revealed that the mechanism of phenol adsorption onto NL and ACL was not only controlled by film diffusion but also by intraparticle diffusion. Also, a thermo-dynamic study identified the non-spontaneous and exothermic nature of adsorption. The research determined that NL and ACL could be promising and potential adsorbents for the removal of phenol from contaminated water.