The sorption of three pesticides (chlorpyrifos, metalaxyl and penconazole) by a commercial clay montmorillonite and by the same mineral modified with two different cationic-surfactant micelles was studied in this work. Both micelle–clay complexes, commercial names Cloisite 20A and Cloisite 30B, showed a good capacity to sorb all three pesticides from water, whereas the sorption of the three pesticides on the natural montmorillonite was not described by an isotherm. Modeling sorption data obtained from both micelle–clay complexes showed that the Freundlich sorption constant (KF = 7.76) was higher for chlorpyrifos on Cloisite 20A than on Cloisite 30B (KF = 5.91), whereas the sorption of metalaxyl was stronger on Cloisite 30B (KF = 1.07) than on Cloisite 20A (KF = 0.57). Moreover the micelle–clay complex Cloisite 20A showed also a good affinity for penconazole, the maximum quantity adsorbed (qm) of 6.33 mg g-1 being 45% more than the maximum quantity adsorbed on Cloisite 30B. Single-batch adsorption of each of these pesticides onto both micelle–clay complexes was studied using the Freundlich isotherm equation for chlorpyrifos and metalaxyl and the Langmuir isotherm for penconazole. The Cloisite 20A micelle–clay complex adsorbent was predicted to require 23% less of the adsorbent to treat certain volumes of wastewater containing 30 mg L-1 chlorpyrifos, 43% more to treat metalaxyl similarly and 57% less to treat penconazole compared with Cloisite 30B.
|Titolo:||Assessing Modified Clays as Adsorbent for Decontaminate Agricultural Waste Water by Chlorpyrifos, Penconazole and Metalaxyl Residues|
SUCIU, NICOLETA (Primo)
|Data di pubblicazione:||2009|
|Parole Chiave:||modified clays ; natural montmorillonite ; pesticide ; maximum adsorption ; process design|
|Citazione:||Assessing Modified Clays as Adsorbent for Decontaminate Agricultural Waste Water by Chlorpyrifos, Penconazole and Metalaxyl Residues / N.A. Suciu, E. Capri. ((Intervento presentato al 1. convegno Young Environmental Scientists Meeting (YES Meeting) tenutosi a Landau (Germany) nel 2009.|
|Appare nelle tipologie:||14 - Intervento a convegno non pubblicato|