Complete removal of AHPS synthetic dye from water using new electro-fenton oxidation catalyzed by natural pyrite as heterogeneous catalyst.
The mineralization of a new azo dye - the (4-amino-3-hydroxy-2-p-tolylazo-naphthalene-1-sulfonic acid) (AHPS) - has been studied by a novel electrochemical advanced oxidation process (EAOP), consisting in electro-Fenton (EF) oxidation, catalyzed by pyrite as the heterogeneous catalyst - the so-called 'pyrite-EF'. This solid pyrite used as heterogeneous catalyst instead of a soluble iron salt, is the catalyst the system needs for production of hydroxyl radicals. Experiments were performed in an undivided cell equipped with a BDD anode and a commercial carbon felt cathode to electrogenerate in situ H2O2 and regenerate ferrous ions as catalyst. The effects on operating parameters, such as applied current, pyrite concentration and initial dye content, were investigated. AHPS decay and mineralization efficiencies were monitored by HPLC analyses and TOC measurements, respectively. Experimental results showed that AHPS was quickly oxidized by hydroxyl radicals (OH) produced simultaneously both on BDD surface by water discharge and in solution bulk from electrochemically assisted Fenton's reaction with a pseudo-first-order reaction. AHPS solutions with 175 mg L(-1) (100 mg L(-1) initial TOC) content were then almost completely mineralized in 8h. Moreover, the results demonstrated that, under the same conditions, AHPS degradation by pyrite electro-Fenton process was more powerful than the conventional electro-Fenton process.
Département de chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia.
Lazhar
L
Labiadh
Université Paris-Est Laboratoire Géomatériaux et Environnement, EA 4508, UPEM, 5 Bd Descartes, 77454 Marne-la-Vallée, Cedex 2, France. Electronic address: mehmet.oturan@univ-paris-est.fr.
Mehmet A
MA
Oturan
Department of Civil, Chemical and Environmental Engineering, University of Genoa, P. le J.F. Kennedy 1, Genoa 16129 Italy.
Marco
M
Panizza
Département de chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia; Chemistry Department, College of Science, IMSIU (Al-Imam Mohammad Ibn Saud Islamic University), Riyadh 11623, Saudi Arabia.
Nawfel Ben
NB
Hamadi
Département de chimie, Faculté des Sciences de Gabès, Université de Gabès, Cité Erriadh, 6072 Gabès, Tunisia.
Salah
S
Ammar
D001391:Azo Compounds / Q000302:isolation & purification*; D002384:Catalysis; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D015394:Molecular Structure; D009282:Naphthalenesulfonates / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D013440:Sulfides / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
C000607795:4-amino-3-hydroxy-2-p-tolylazonaphthalene-1-sulfonic acid; D001391:Azo Compounds; C045076:Fenton's reagent; D009282:Naphthalenesulfonates; D013440:Sulfides; D014874:Water Pollutants, Chemical; C011342:pyrite; D006861:Hydrogen Peroxide; D007501:Iron
AHPS; BDD anode; Heterogeneous catalyst; Hydroxyl radical; Mineralization; Pyrite electro-Fenton