کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4409026 1307457 2013 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photocatalytic degradation of the herbicide clomazone in natural water using TiO2: Kinetics, mechanism, and toxicity of degradation products
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست شیمی زیست محیطی
پیش نمایش صفحه اول مقاله
Photocatalytic degradation of the herbicide clomazone in natural water using TiO2: Kinetics, mechanism, and toxicity of degradation products
چکیده انگلیسی


• UV/TiO2 treatment eliminates efficiently clomazone from water.
• Photocatalytic degradation follows the pseudo-first order kinetics.
• Five intermediates were identified by LC–ESI–MS/MS and 1H NMR.
• Toxicity toward the H-4-II-E and MRC-5 cell lines decreased by irradiation.
• River, ground, and thermal water lower the rate of photodegradation.

The photocatalytic degradation of the herbicide clomazone (0.05 mM) in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum concentration of the catalyst was found to be 0.50 mg mL−1 under UV light at the pH 10.3. In the first stage of the reaction, the photocatalytic degradation of clomazone followed the pseudo-first order kinetics, with and the heterogeneous catalysis proceeding via OH radicals. The results also showed that the disappearance of clomazone led to the formation of a number of organic intermediates and ionic byproducts, whereas its complete mineralization occurred after about 55 min. Tentative photodegradation pathways were proposed and discussed. A comparison of the evolution of toxicity that was evaluated in vitro in rat hepatoma (H-4-II-E) and human fetal lung (MRC-5) cell lines with the degradation kinetics indicates that the irradiation contributed to the decrease of the toxicity of the mixture that is no longer dominated by the parent compound. The study also encompassed the effect of the quality of natural water on the rate of removal of clomazone.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemosphere - Volume 93, Issue 1, September 2013, Pages 166–171
نویسندگان
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