Efficient removal of atrazine in water with a Fe3O4/MWCNTs nanocomposite as a heterogeneous Fenton-like catalyst

Abstract

Fe₃O₄ and multi-walled carbon nanotube hybrid materials (Fe₃O₄/MWCNTs) were synthesized by a coprecipitation combined hydrothermal method. The nanocomposites were applied for adsorption and degradation of atrazine (ATZ) in the presence of H₂O₂. The obtained catalysts were characterized by TEM, XRD, BET, XPS and Raman spectroscopy. The effects of solution pH, catalysts dosage, H₂O₂ concentration and iron leaching on the degradation of ATZ were investigated. Fe₃O₄/MWCNTs showed a higher utilization efficiency of H₂O₂, higher ability of adsorption for ATZ and higher degradation efficiency of ATZ than Fe₃O₄ nanoparticles in the batch degradation experiment. The degradation efficiency increased with the solution pH decreasing from 8.0 to 3.0. The catalytic results showed that Fe₃O₄/MWCNTs presented good performance for the degradation of ATZ, achieving 81.4% decomposition of ATZ after 120 min at reaction conditions of H₂O₂ concentration 3.0 mmol L⁻¹, catalysts dosage 0.1 g L⁻¹, ATZ concentration 10.0 mg L⁻¹, pH 5.0 and T 30 °C. Three degradation products (desethylatrazine, desisopropylatrazine, and 2-hydroxyatrazine) were detected during a heterogeneous Fenton reaction in solution. The stability, and reusability of Fe₃O₄/MWCNTs for ATZ degradation were also investigated.