Oxidation of the pesticide atrazine at DSA electrodes.
This paper presents the study of the electrochemical oxidation of the pesticide atrazine at a Ti/Ru(0.3)Ti(0.7)O(2) dimensionally stable anodes (DSA). The effect of using different supporting electrolytes (NaCl, NaOH, NaNO(3), NaClO(4), H(2)SO(4) and Na(2)SO(4)) during the galvanostatic electrolysis of atrazine was investigated. It was observed that the removal of atrazine and total organic carbon (TOC) was only achieved at appreciable rates when NaCl was used as the supporting electrolyte, due to the oxidising species formed in this electrolyte (e.g. ClO(-)). Variation of the NaCl concentration demonstrated that, although only low concentrations of NaCl are necessary to result in the complete removal of atrazine in solution, TOC removal is almost linearly dependent on the quantity of NaCl in solution. Examination of the applied current density indicates that the efficiency of TOC removal reaches a maximum at 60 mA cm(-2). Testing of alternative electrode materials containing SnO(2) did not improve the efficiency of atrazine removal in Na(2)SO(4), but in NaCl a small increase was observed. Overall there appears to be no great advantage in using SnO(2)-containing electrodes over the Ti/Ru(0.3)Ti(0.7)O(2) electrode.
Malpass
G R P
GR
Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil. gmalpass@iqsc.usp.br
Miwa
D W
DW
Machado
S A S
SA
Olivi
P
P
Motheo
A J
AJ
D001280:Atrazine / Q000032:analysis / Q000737:chemistry*; D002244:Carbon; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004572:Electrolysis / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010575:Pesticides / Q000032:analysis / Q000737:chemistry*; D017971:Tin Compounds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
D007220:Industrial Waste; D010575:Pesticides; D017971:Tin Compounds; D014874:Water Pollutants, Chemical; D002244:Carbon; D014025:Titanium; C045358:stannic oxide; D001280:Atrazine