| Abstract | The aim of this work is to investigate the efficiency of the phyllomanganate birnessite in degrading catechol after mechanochemical treatments. A synthesized birnessite and the organic molecule were grounded together in a high energy mill and the xenobiotic-mineral surface reactions induced by the grinding treatment have been investigated by means of X-ray powder diffraction, X-ray fluorescence, thermal analysis and spectroscopic techniques as well as high-performance liquid chromatography and voltammetric techniques.If compared to the simple contact between the birnessite and the organic molecule, mechanochemical treatments have revealed to be highly efficient in degrading catechol molecules, in terms both of time and extent. Due to the two phenolic groups of catechol and the small steric hindrance of the molecule, the extent of the mechanochemically induced degradation of catechol onto birnessite surfaces is quite high. The degradation mechanism mainly occurs via a redox reaction. It implies the formation of a surface bidentate inner-sphere complex between the phenolic group of the organic molecules and the Mn(IV) from the birnessite structure. Structural changes occur on the MnO 6 layers of birnessite as due to the mechanically induced surface reactions: reduction of Mn(IV), consequent formation of Mn(III) and new vacancies, and free Mn 2+ ions production. |
| Text | 206325 2012 10.1016/j.jhazmat.2011.11.054 ISI Web of Science WOS 000300262400019 Scopus 2 s2.0 84855344306 Birnessite Catechol Mechanochemistry Abiotic degradation Mechanochemical transformation of an organic ligand on mineral surfaces The efficiency of birnessite in catechol degradation Di Leo P., Pizzigallo MDR., Ancona V., Di Benedetto F., Mesto E., Schingaro E., Ventruti G. CNR IMAA, Consiglio Nazionale delle Ricerche Istituto di Metodologie per l Analisi Ambientale, C.da S. Loja, Zona Industriale, 85050 Tito Scalo PZ , Italy. Dipartimento di Biologia e Chimica Agroforestale e Ambientale, Universita di Bari Aldo Moro, Via Amendola 165/a, 70126 Bari, Italy. Consiglio Nazionale delle Ricerche Istituto di Ricerca sulle Acque, Via F. De Blasio 5, 70132 Bari, Italy. Dipartimento di Chimica, Universita di Firenze, Via della Lastruccia, 3, 50019 Sesto Fiorentino, Italy. Dipartimento di Scienze della Terra e Geoambientali, Universita di Bari Aldo Moro, Via Orabona, 4, 70125 Bari, Italy. The aim of this work is to investigate the efficiency of the phyllomanganate birnessite in degrading catechol after mechanochemical treatments. A synthesized birnessite and the organic molecule were grounded together in a high energy mill and the xenobiotic mineral surface reactions induced by the grinding treatment have been investigated by means of X ray powder diffraction, X ray fluorescence, thermal analysis and spectroscopic techniques as well as high performance liquid chromatography and voltammetric techniques.If compared to the simple contact between the birnessite and the organic molecule, mechanochemical treatments have revealed to be highly efficient in degrading catechol molecules, in terms both of time and extent. Due to the two phenolic groups of catechol and the small steric hindrance of the molecule, the extent of the mechanochemically induced degradation of catechol onto birnessite surfaces is quite high. The degradation mechanism mainly occurs via a redox reaction. It implies the formation of a surface bidentate inner sphere complex between the phenolic group of the organic molecules and the Mn IV from the birnessite structure. Structural changes occur on the MnO 6 layers of birnessite as due to the mechanically induced surface reactions reduction of Mn IV , consequent formation of Mn III and new vacancies, and free Mn 2 ions production. 201 Mechanochemical transformation of an organic ligand on mineral surfaces The efficiency of birnessite in catechol degradation Journal_of_Hazardous_Materials_Vol_201_pp_148_154_anno_2012.pdf Articolo in rivista Elsevier 0304 3894 Journal of hazardous materials Print Journal of hazardous materials Print J. hazard. mater. Print Journal of hazardous materials. Print paola.dileo DI LEO PAOLA valeria.ancona ANCONA VALERIA PC.P06.008.002 Metodologie integrate per lo studio archeometrico di siti di interesse archeologico |
