Scheda di dettaglio – i prodotti della ricerca
| Dato | Valore |
|---|---|
| Title | SEQUESTRATION OF CATECHOL AND PENTACHLOROPHENOL BY MECHANOCHEMICALLY TREATED KAOLINITE |
| Abstract | The pollution of soils by organic contaminants, such as phenols, is a serious problem because of the high toxicity and persistence in the environment. Mechanochemical treatments (MTs) of polluted soils with minerals, such as clays and oxides, which have surfaces that exhibit catalytic properties, have been suggested to be a new useful strategy to promote both organic and inorganic pollutant degradation. Nevertheless, much still remains to be studied about the capability of clays to promote pollutant removal by means of the mechanochemical activation of the mineral surfaces. This work investigates the efficiency of the mineral kaolinite in promoting the sequestration of catechol (CAT) and pentachlorophenol (PCP) by MT. A well crystallized kaolinite (KGa-1b) was milled for prolonged times with different amounts of organic molecules so as to obtain two different clay: organic compound ratios. Prolonged grinding and a higher clay mineral: organic compound ratio were found to be more effective in promoting a stronger removal than simple contact. After 1 h of mechanochemical treatment, the PCP and CAT removal percentages were 32% and 20%, respectively. Additionally, a 7-day undisturbed incubation of the milled mixtures produced a trend for increased CAT removal (up to 40%). The interaction mechanism between kaolinite and each organic compound (i.e. CAT and PCP) after a MT was inferred by integrating information from spectroscopic, diffractometric, and chromatographic analyses. X-ray diffraction and Fourier-transform infrared data suggested a strong interaction between CAT and KGa-1b. This interaction mechanism likely occurs through the formation of an inner-sphere complex by H-bonding between the organic molecules and the oxygens of the kaolinite tetrahedral sheet. On the other hand, a weak interaction (i.e. van der Waals type) can occur between the KGa-1b O-planes and the PCP molecules, which likely bind to the external surfaces of KGa-1b. |
| Source | Clays and clay minerals 64 (5), pp. 513–522 |
| Keywords | CatecholKaoliniteMechanochemical TreatmentPentachlorophenol |
| Journal | Clays and clay minerals |
| Editor | Symposium Publications Division, Pergamon Press,, New York, Stati Uniti d'America |
| Year | 2016 |
| Type | Articolo in rivista |
| DOI | 10.1346/CCMN.2016.064031 |
| Authors | Ancona, Valeria; Di Leo, Paola; Pizzigallo, Maria Donata Rosa |
| Text | 372236 2016 10.1346/CCMN.2016.064031 ISI Web of Science WOS 000396825300001 Scopus 2 s2.0 85012041391 Catechol Kaolinite Mechanochemical Treatment Pentachlorophenol SEQUESTRATION OF CATECHOL AND PENTACHLOROPHENOL BY MECHANOCHEMICALLY TREATED KAOLINITE Ancona, Valeria; Di Leo, Paola; Pizzigallo, Maria Donata Rosa CNR; CNR; Univ Bari Aldo Moro The pollution of soils by organic contaminants, such as phenols, is a serious problem because of the high toxicity and persistence in the environment. Mechanochemical treatments MTs of polluted soils with minerals, such as clays and oxides, which have surfaces that exhibit catalytic properties, have been suggested to be a new useful strategy to promote both organic and inorganic pollutant degradation. Nevertheless, much still remains to be studied about the capability of clays to promote pollutant removal by means of the mechanochemical activation of the mineral surfaces. This work investigates the efficiency of the mineral kaolinite in promoting the sequestration of catechol CAT and pentachlorophenol PCP by MT. A well crystallized kaolinite KGa 1b was milled for prolonged times with different amounts of organic molecules so as to obtain two different clay organic compound ratios. Prolonged grinding and a higher clay mineral organic compound ratio were found to be more effective in promoting a stronger removal than simple contact. After 1 h of mechanochemical treatment, the PCP and CAT removal percentages were 32% and 20%, respectively. Additionally, a 7 day undisturbed incubation of the milled mixtures produced a trend for increased CAT removal up to 40% . The interaction mechanism between kaolinite and each organic compound i.e. CAT and PCP after a MT was inferred by integrating information from spectroscopic, diffractometric, and chromatographic analyses. X ray diffraction and Fourier transform infrared data suggested a strong interaction between CAT and KGa 1b. This interaction mechanism likely occurs through the formation of an inner sphere complex by H bonding between the organic molecules and the oxygens of the kaolinite tetrahedral sheet. On the other hand, a weak interaction i.e. van der Waals type can occur between the KGa 1b O planes and the PCP molecules, which likely bind to the external surfaces of KGa 1b. 64 Published version https //www.scopus.com/record/display.uri eid=2 s2.0 85012041391 origin=resultslist sort=plf f src=s st1= st2= sid=1b91022be26f71a1b4ef5d9284607746 sot=b sdt=b sl=101 s=TITLE ABS KEY%28SEQUESTRATION OF CATECHOL AND PENTACHLOROPHENOL BY MECHANOCHEMICALLY TREATED KAOLINITE%29 relpos=0 citeCnt=3 searchTerm= SEQUESTRATION OF CATECHOL AND PENTACHLOROPHENOL BY MECHANOCHEMICALLY TREATED KAOLINITE Ancona et al., CCM_2016 Ancona et al_CCM_2016.pdf Articolo in rivista Symposium Publications Division, Pergamon Press, 0009 8604 Clays and clay minerals Clays and clay minerals Clays and clay miner. Clays and clay minerals. paola.dileo DI LEO PAOLA valeria.ancona ANCONA VALERIA |