Rapid removal of flutriafol in water by zero-valent iron powder

• Published in: Chemosphere (Oxford) Vol. 71; no. 5; pp. 816 - 826
• Main Author: Ghauch, Antoine
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2008; Elsevier
• Subjects: Agronomy. Soil science and plant productions; Applied sciences; Biological and medical sciences; Biological and physicochemical phenomena; Chromatography, High Pressure Liquid; Decontamination. Miscellaneous; Degradation; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Flutriafol; Fundamental and applied biological sciences. Psychology; fungicide residues; HPLC–DAD(APPI)–MS; HPLC–DAD–FLU; iron; Iron - chemistry; Kinetics; Mass Spectrometry; Molecular Structure; Natural water pollution; Pesticides - chemistry; Pesticides - toxicity; Pollution; Pollution, environment geology; powders; reducing agents; reduction; Soil and sediments pollution; Soil and water pollution; Soil science; Spectrophotometry, Ultraviolet; Time Factors; triazole fungicides; Triazoles - chemistry; Triazoles - toxicity; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; water pollution; Water Purification - methods; water treatment; Water treatment and pollution; zero valence iron; ZVI; Degradation; HPLC–DAD–FLU; Flutriafol; ZVI; HPLC–DAD(APPI)–MS; HPLC chromatography; Zerovalent metal; Iron; Soil pollution; Powder; Persistent organic pollutant; Decontamination; Reaction mechanism; Diode array; Organic compounds; Fluorescence detector; HPLC-DAD(APPI)-MS; Pesticides; Chemical degradation; Photodiode; Chemical reaction kinetics; Fungicide; Triazole derivatives; Water pollution; HPLC-DAD-FLU; Degradation product; Ultraviolet visible spectrometry
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.11.057

A study of the effect of zero-valent iron (ZVI) powder is carried out for the first time on the degradation of flutriafol (( RS)-2,4′-difluoro-α-(1 H-1,2,4-triazol-1-ylmethyl)-benzhydryl alcohol, C 16H 13F 2N 3O), a bifluorinated soil and water persistent triazole pesticide using a laboratory scale device consisting of a 20 ml pyrex serum vials fixed to a Vortex agitator. Different amounts of ZVI powder (10–50 g l −1) at pH 6.6 and room temperature were investigated. Experiments showed an observed degradation rate k obs directly proportional to the surface of contact of flutriafol with ZVI. Flutriafol degradation reactions demonstrated first order kinetic with a half-live of about 10.8 ± 0.5 min and 3.6 ± 0.2 min when experiments were conducted at [ZVI] = 10 g l −1 into oxygenated and anoxic solutions, respectively. Three analytical techniques were employed to monitor flutriafol degradation and to understand solution and by-products behaviors: (1) A UV–Vis spectrophotometer; (2) a high performance liquid chromatography (HPLC) coupled with a photo diode array (PDA) and fluorescence detectors; (3) a similar HPLC coupled with a PDA and a mass spectrometer detectors equipped with an atmospheric pressure photoionization source. Results showed a complete disappearance of flutriafol after 20 min of contact with ZVI, the loss of fluorescence properties of the final by-products, the defluorination of the triazole pesticide via hydroxylation reaction and finally the hydrogenation of the triazole ring.