Résumé:
The objective of this study is to develop a combined method of adsorption and
Electro-Fenton oxidation for the removal of Amoxicillin (AMX) and Paracetamol (PCM)
from synthetically prepared solutions. The biosorbent, derived from Brahea Edulis palm
leaf fibers (FBE), was employed as an adsorbent agent in the first stage of treatment for
each pollutant individually. The FBE biosorbent was characterized using FTIR, SEM,
BET, and XRD, revealing an irregular, rough surface morphology with a well-formed
porous structure and a specific surface area of 124 m²/g. The optimal conditions for the
adsorption of AMX were found to be at pH 6, with an FBE concentration of 6 g/L, an
initial adsorbate concentration of 50 mg/L, and a contact time of 90 minutes, achieving a
removal efficiency of approximately 58%. In contrast, the removal rate for PCM by
adsorption reached over 89%. Thermodynamic analysis indicated that the adsorption of
AMX is spontaneous and endothermic, with a reaction enthalpy of 37.155 kJ/mol, while
the adsorption of PCM is spontaneous and exothermic, with an enthalpy of 17.085 kJ/mol.
The kinetic study showed that the adsorption process of both pharmaceutical pollutants
follows a second-order model. Additionally, the adsorption isotherm modeling
demonstrated that the Langmuir model best describes the adsorption process for both AMX
and PCM, compared to the Freundlich and Temkin models.
In the second part of this study, the feasibility of applying the Electro-Fenton
process for treating AMX and PCM in an aqueous solution was assessed. The optimal
conditions for the Electro-Fenton reaction, using a platinum anode and a carbon felt
cathode, were determined as follows: a ferrous iron concentration of 0.1 mM, a current
intensity of 300 mA, and a pH of 3, with an initial concentration of 0.13 mM for AMX and
0.33 mM for PCM. Under these optimal conditions, the degradation rates reached 96% for
AMX and 94% for PCM, with energy consumptions of 8.25 kWh/kg for AMX and 8.42
kWh/kg for PCM.
In the final part of the study, the treatment of these pollutants using the ElectroFenton process followed by FBE filtration was evaluated. The degradation efficiencies
achieved by the Electro-Fenton process were 96% for AMX and 94% for PCM. SEM
analysis of the FBE after filtering the oxidized solutions revealed that iron had been
adsorbed into the pores of the FBE. The presence of iron in the adsorbent pores indicates
that FBE can be effectively used as an adsorbent to remove the residual iron generated by
the Electro-Fenton process.
