1,721,059 research outputs found
Evaluating the representativeness of pesticide leaching fieldstudies at the European level: a promising procedure
No full textAssessing Modified Clays as Adsorbent for Decontaminate Agricultural Waste Water by Chlorpyrifos, Penconazole and Metalaxyl Residues
No full textThe 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
John Singer Sargent tra Napoli e Capri. Un'estate fortunysta
No full textL'articolo analizza l'influenza della scuola fortunysta partenopea (Antonio Mancini, Francesco Paolo Michetti e Vincenzo Gemito) su John Singer Sargent durante il suo soggiorno tra Napoli e Capri nell'estate del 1878
Biomassbed: un sistema biologico per ridurre le contaminazioni puntiformi da fitofarmaci di origine aziendale
No full textDeposition and dissipation of chlorpyrifos in surface water following vineyard applications in northern Italy
No full textChlorpyrifos is an insecticide approved globally for use on a wide range of crops. Laboratory studies indicate that chlorpyrifos is toxic to fish and aquatic invertebrates, and so the adoption of practices that reduce aquatic exposure following use should be encouraged. This study assessed the exposure of surface water to the spray-drift of chlorpyrifos and the subsequent contamination of a realistic worst-case edge-of-field ditch in a vineyard in Northern Italy. Chlorpyrifos (DURSBAN 480 EC® [Dow Elanco, Indianapolis, IN, USA]) was applied according to local Good Agricultural Practice (GAP) on two vineyard plots using atomizer equipment. Drift deposition and subsequent dissipation of chlorpyrifos were then monitored in an adjacent, common ditch, with an inherent buffer zone of approximately 7 m between the treated area and the ditch. The results showed that the drift loadings under the study conditions could reach predicted levels from standard spray-drift tables. However, the measured drift was highly variable due to physical factors such as the crop canopy and the distribution of vines within the rows. The amount of chlorpyrifos deposited onto the surface of the ditch water and intercepted by paper strips was approximately 2% of the applied amount after the two applications, with a maximum concentration of approximately 0.3 μg L -1 immediately after the first application and 0.09 μg L -1 after the second, which then dissipated from the water column within 12 to 24 h. The results showed that drift deposition spatially was variable and that chlorpyrifos residues dissipated rapidly from this surface water body. Both aspects are considered important in order to refine the aquatic risk assessment at a higher tier for both registration and management purposes
Perspectives of the prediction of pesticide environmental concentrations and related questions
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