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Sorption, kinetics and thermodynamics studies of atrazine herbicide removal from water using iron nano-composite material
Ali, I.; ALOthman, Z.A. & Al-Warthan, A.
Abstract
Atrazine organic pollutant has been found in
several water resources of the world. It is highly toxic and
carcinogenic in nature. Atrazine is removed by adsorption
on iron composite nanoparticles. The composite nanoparticles
were synthesized, analyzed and applied for atrazine
uptake from water. Residual atrazine was monitored by gas
chromatography–mass spectrometry. The maximum atrazine
removal (95 %) was achieved using contact time
30.0 min, concentration 30.0 µg/L, pH 7.0, dose 2.5 g/L
and temperature 20.0 °C. The adsorbent was selective for
atrazine adsorption. The results obeyed Langmuir, Freundlich,
Temkin and Dubinin–Radushkevich isotherms.
∆G° values were -6.05, -6.11 and -6.15 kJ/mol at 20, 25
and 30 °C temperatures, respectively. The value of ∆S°
was -2.45 × 10-3 kJ/mol K. It showed decline in entropy
of atrazine uptake. The adsorption followed pseudo-second-
order kinetics. The adsorption mechanism was liquid
film diffusion. The proposed adsorption method is inexpensive,
fast and reproducible. It can be used to remove
atrazine from any water sample/source.
Keywords
Adsorption; Atrazine; Gas chromatography– mass spectrometry; Iron composite nanoparticles; Isotherms; Kinetics; Thermodynamics; Water treatment
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