Use of Fe(II)Fe(III)-LDHs prepared by co-precipitation method in a heterogeneous-Fenton process for degradation of Methylene Blue

The present study focused on the degradation of Methylene Blue in a heterogeneous Fenton-like process catalyzed by a type of new heterogeneous catalyst named Fe(II)Fe(III)-LDHs. The three Fe(II)Fe(III)-LDHs catalysts were prepared by co-precipitation of FeSO4.7H(2)O and Fe-2(SO4)(3). The results indicated that all three Fe(II)Fe(III)-LDHs synthesized showed good catalytic activity, and the most active catalyst toward Methylene Blue decomposition was prepared at the ratio [Fe2+]/[Fe3+] = 1:0 at air atmosphere. The degradation of MB performed well at acidic and neutral conditions, 100% color removal of Methylene Blue (10 mg/L) was achieved in 1 h, and the fastest reaction rate obtained at pH 3 according to the pseudosecond order reaction kinetic was 6.185. During the degradation process of Methylene Blue, the solution pH was found to be decreased, and Cl-, SO42-, NO3- were determined. Pleiocarpamine, DL-Norleucine and benzothiazole that have rarely been detected in previous reports about the other heterogeneousFenton processes were observed. Methylene Blue degraded in two different pathways simultaneously, and finally the intermediates were mineralized to water and dioxide. In term of the distinctive characteristics of Fe(II)Fe(III)-LDHs, the heterogeneous Fenton process catalyzed by Fe(II)Fe(III)-LDHs was promising in wastewater treatment. C) 2014 Elsevier B.V. All rights reserved.