Photocatalytic degradation of the herbicides propanil and molinate over aqueous TiO2 suspensions: identification of intermediates and the reaction pathway
Φόρτωση...
Ημερομηνία
Συγγραφείς
Konstantinou, I. K.
Sakkas, V. A.
Albanis, T. A.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Elsevier
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Applied Catalysis B-Environmental
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The light-induced degradation of propanil and molinate under simulated solar irradiation has been investigated in aqueous solutions containing TiO2 suspensions as photocatalysts. The study focus on the identification of possible intermediate products and the determination of inorganic ions formed during the process, using several powerful analytical techniques such as gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC). The primary degradation of propanil and molinate has been a fast process with half-lives varied from 4.3 to 2.9 min, respectively, and followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. The stoichiometric transformation of organic chlorine into chloride ion and organic sulfur to sulfate ions was observed for propanil and molinate, respectively, whereas oxidation of nitrogen to nitrate ions took place at delayed irradiation times for both herbicides. The mineralization of the organic carbon to CO2 after 240 min of irradiation was found to be greater than or equal to 95% for both herbicides. Various organic intermediates detected during the treatment have been identified by GC-MS techniques. Based on this by-product identification, a possible multi-step degradation scheme was proposed for each herbicide including hydroxylation, dechlorination, dealkylation and oxidation steps that lead to the mineralization of the starting molecule. This work points to the necessity of extended knowledge of the successive steps in a solar-assisted detoxification process. (C) 2001 Elsevier Science BN. All rights reserved.
Περιγραφή
Λέξεις-κλειδιά
photocatalytic oxidation, tio2, propanil, molinate, photoproduct analysis, titanium-dioxide, chloroacetic acids, oxidation, water, decomposition, chromatography, transformation, metabolites, pesticides, parathion
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000172080200005
http://ac.els-cdn.com/S0926337301002181/1-s2.0-S0926337301002181-main.pdf?_tid=4a83cb505c7b5110cbb49f2f3609dd16&acdnat=1333023150_2a9e79106c49314267e9d2974d415c43
http://ac.els-cdn.com/S0926337301002181/1-s2.0-S0926337301002181-main.pdf?_tid=4a83cb505c7b5110cbb49f2f3609dd16&acdnat=1333023150_2a9e79106c49314267e9d2974d415c43
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας