Humic Acid–Fe(Hydr)oxide Composites Supported on Montmorillonite: Synthesis, Characterization, and Atrazine Adsorption

BORGNINO, LAURA; BIA, GONZALO; ORTIZ, PATRICIA I.; PFAFFEN, VALERIA

JOURNAL OF CHEMICAL AND ENGINEERING DATA

AMER CHEMICAL SOC

Año: 2017 vol. 62 p. 3793 - 3801

0021-9568

Much progress has been made involving the interaction of atrazine (Atz) with natural geosorbents likeFe(hydr)oxides, organic matter, and clay minerals. However, the properties of the humic acid−Fe(hydr)oxides-clay compositesdiffer from their individual member phases, exerting an influence on the adsorption capacity and stability of the system. In thiswork, the evaluation of Atz adsorption onto humic acid−Fe(hydr)oxide supported on montmorillonite (HA−FeM) wasperformed. A combination of the X-ray diffraction pattern and batch adsorption experiments at different pH and ionic strengthconditions were performed. The identification of the surface groups involved in the interaction FeM−Atz was carry out using Xrayphotoelectron spectroscopy. The presence of Fe(hydr)oxides and humic acid improve the adsorption capacity ofmontmorillonite. Acidic pH and high ionic strength conditions further increases the adsorption. The heterogeneity of the surfacesites and cooperative effect contributes to the adsorption process. However, the hydrophobic character of the herbicide is the keyfactor controlling adsorption. The results obtained from this work give insights about the adsorption mechanism of Atz ontohumic acid Fe(hydr)oxides-clay composites and provide information about the potentiality of this type of material to be used toremove organic pollutants present in the aquatic environment.