Elimination of phenol and aromatic compounds by zero valent iron and EDTA at low temperature and atmospheric pressure.
This work deals with a new abiotic oxidation process designed as a suitable pre-treatment step within a biological depuration of wastewater containing phenol or its derivatives (o-cresol, 2-chlorophenol and p-nitrophenol) or aniline. The reaction was carried out in a stirred tank reactor at 20 degrees C and atmospheric pressure in presence of the organic compound, 150mgl(-1), zero valent iron particles (10g), ethylenediamine tetraacetic acid (EDTA, 101mgl(-1)) and air. The experimental results show that 85% of phenol conversion can be achieved after 360min. 2-Chlorophenol was found to be more easily degradable and it is completely eliminated after 300min. The oxidation of o-cresol and aniline behaved more closely to phenol obtaining after 360min 70% and 68% of conversion respectively. p-Nitrophenol was a very refractory compound, giving only 28% of conversion after 360min. Moreover, the influence of some operating variables was studied over the following ranges: temperature from 20 to 50 degrees C, initial phenol concentration from 150 to 1000mgl(-1), EDTA concentration from 50 to 200mgl(-1) and iron particles from 5 to 20g. As expected, temperature strongly enhances phenol conversion. Also, an increase of the catalyst to phenol ratio or the iron or EDTA to phenol ratio improves the reaction rate. A preliminary kinetic analysis of the data shown that the rate of phenol disappearance is not first order with respect to the phenol.
Sanchez
Irama
I
Departament d'Enginyeria Química, Escola Tècnica Superior d'Enginyeria Química, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain.
Stüber
Frank
F
Font
Josep
J
Fortuny
Agustí
A
Fabregat
Azael
A
Bengoa
Christophe
C
D000814:Aniline Compounds / Q000737:chemistry*; D001274:Atmospheric Pressure; D002384:Catalysis; D002733:Chlorophenols / Q000737:chemistry; D003408:Cresols / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods; D007501:Iron / Q000737:chemistry*; D009596:Nitrophenols / Q000737:chemistry; D010084:Oxidation-Reduction; D010636:Phenols / Q000302:isolation & purification*; D013696:Temperature; D018508:Water Purification / Q000379:methods*
D000814:Aniline Compounds; D002733:Chlorophenols; D003408:Cresols; D009596:Nitrophenols; D010636:Phenols; D004492:Edetic Acid; D007501:Iron; C030683:2-chlorophenol; C023650:aniline; C024836:4-nitrophenol; C034047:2-cresol