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Adsorption kinetics and thermodynamics of organophosphorus profenofos pesticide onto Fe/Ni bimetallic nanoparticles
Mansouriieh, N.; Sohrabi, M. R. & Khosravi, M.
Abstract
Bimetallic Fe/Ni nanoparticles were synthesized
and used for the removal of profenofos organophosphorus
pesticide from aqueous solution. These novel bimetallic
nanoparticles (Fe/Ni) were characterized by scanning electron
microscopy, energy-dispersive X-ray analysis spectroscopy,
X-ray diffraction, and Fourier transform infrared
spectroscopy. The effect of the parameters of initial pesticide
concentration, pH of the solution, adsorbent dosage, temperature,
and contact time on adsorption was investigated.
The adsorbent exhibited high efficiency for profenofos
adsorption, and equilibrium was achieved in 8 min. The
Langmuir, Freundlich, and Temkin isotherm models were
used to determine equilibrium. The Langmuir model showed
the best fit with the experimental data (R2 = 0.9988).
Pseudo-first-order, pseudo-second-order, and intra-particle
diffusion models were tested to determine absorption
kinetics. The pseudo-second-order model provided the best
correlation with the results (R2 = 0.99936). The changes in
the thermodynamic parameters of Gibb’s free energy,
enthalpy, and entropy of the adsorption process were also
evaluated. Thermodynamic parameters indicate that profenofos
adsorption using Fe/Ni nanoparticles is a spontaneous
and endothermic process. The value of the activation
energy (Ea = 109.57 kJ/mol) confirms the nature of the
chemisorption of profenofos onto Fe/Ni adsorbent.
Keywords
Chemisorption; Environmental remediation; Isotherm model; Thermodynamic parameters
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