A comparative study of electrochemical oxidation of methidation organophosphorous pesticide on SnO2 and boron-doped diamond anodes.
BACKGROUND
Electrochemical oxidation considered to be among the best methods in waste water desalination and removing toxic metals and organic pesticides from wastewater like Methidathion. The objective of this work is to study the electrochemical oxidation of aqueous wastes containing Methidathion using boron doped diamond thin-film electrodes and SnO2, and to determine the calculated partial charge and frontier electron density parameters.


RESULTS
Electrolysis parameters such as current density, temperature, supporting electrolyte (NaCl) have been optimized. The influences of the electrode materials on methidathion degradation show that BDD is the best electrode material to oxidize this pesticide organophosphorous. Energetic cost has been determinate for all experiments. The results provide that 2 % of NaCl, 60 mA cm(-2) and 25 ºC like the optimized values to carry out the treatment. For BDD the achieved Chemical Oxidation Demand reduction was about 85 %, while for SnO2 it was about 73 %. The BDD anode appears to be the more promising one for the effective electrochemical treatment of methidathion. Finally the theoretical calculation was done by using the calculation program Gaussian 03W, they are a permit to identify the phenomena engaged near the electrode and to completely determine the structures of the products of electrochemical oxidation formed during the degradation and which they are not quantifiable in experiments because of their high reactivity.


CONCLUSIONS
The comparison of the results relating to the two electrodes indicates that these materials have a power to reduce the quantity of the organic matter in the electrolyzed solution. But the speed of oxidation of these compounds is different according to the materials of the electrodes used. Graphical abstract:Structural of methidathion [O,O-dimethyl-S-(5-methoxy-1,3,4-thiadiazolinyl-3-methyl) dithiophosphate] used for study the electrochemical oxidation.
Faculté des Sciences d'Agadir, Laboratoire Matériaux & Environnement, Equipe de Chimie Physique Appliquées, BP 8106, 80000 Agadir, Morocco.
Fatima
F
Hachami
Faculté des Sciences d'Agadir, Laboratoire Matériaux & Environnement, Equipe de Chimie Physique Appliquées, BP 8106, 80000 Agadir, Morocco ; Ecole National des Sciences Appliquées d'Agadir, Laboratoire d'Ingénierie des Procédés de l'Energie & de l'Environnement, BP 1136, 80000 Agadir, Morocco ; Laboratoire d'Innovation et Recherche Appliquée (LIRA), Ecole Polytechnique Université Internationale d'Agadir, 80000 Agadir, Morocco.
Mohamed
M
Errami
Faculté des Sciences d'Agadir, Laboratoire Matériaux & Environnement, Equipe de Chimie Physique Appliquées, BP 8106, 80000 Agadir, Morocco.
Lahcen
L
Bazzi
Faculté des Sciences d'Agadir, Laboratoire Matériaux & Environnement, Equipe de Chimie Physique Appliquées, BP 8106, 80000 Agadir, Morocco.
Mustapha
M
Hilali
Ecole National des Sciences Appliquées d'Agadir, Laboratoire d'Ingénierie des Procédés de l'Energie & de l'Environnement, BP 1136, 80000 Agadir, Morocco.
Rachid
R
Salghi
Department of Chemistry, An-Najah National University, P. O. Box 7, Nablus, State of Palestine.
Shehdeh
S
Jodeh
LCAE-URAC18, Faculty of Sciences, Mohamed 1st University, 60000 Oujda, Morocco.
Belkheir
B
Hammouti
Department of Chemistry, An-Najah National University, P. O. Box 7, Nablus, State of Palestine.
Othman A
OA
Hamed
BDD anode; Electrooxidation; Energy consumption; Methidathion; SnO2 anode