Soil Residues from the Basic Industry as Photoactive Materials in Solar Light Oxidation of 4-Nitrophenol

RODRIGUEZ, MARIA; MADRIZ, LOREAN; CARVAJAL, DAVID; NÚÑEZ, OSWALDO; SCHARIFKER, BENJAMÍN R.; DOMÍNGUEZ, JOSÉ RAMÓN; VARGAS, RONALD

Congreso; LatinXChem 2020 Twitter Conference; 2020

LatinXChem

The accumulation of solid waste due to industrialization has been recognized with a negative impact on the environment and health. In this study, a solid by-product from the iron sulfate production process was evaluated, which presented a total iron around 64.7 ppm, as active raw material to promote like-Fenton process. In a tubular bench reactor, HO? formation has been probed by means of N,N-dimethyl-p-nitrosoaniline as a spin trap, under the following conditions: (i) direct solar light irradiation with H2O2 addition (Photo Fenton) and (ii) direct solar light irradiation with simultaneous electrochemical production of H2O2 (Photo-Electro-Fenton). 4-Nitrophenol (4-NP) has been chosen as a model molecule to test the oxidation process, identifying conditions for its mineralization. The Photo-Electro-Fenton process involves high levels of treatment, determining the condition to convert 98 % of the initial organic matter in 1 hour without accumulation of intermediates. In fact, the fastest pseudo first order degradation rate constant (kobs) was obtained with the possibility of reuse of the solid material, kobs: 0.70 min-1 for the Photo-Electro-Fenton, unlike the Photo-Fenton and Electrochemistry Oxidation process whose kobs were 0.40 min-1 and 0.30 min-1, respectively. The methodology applied in this study demonstrates that industrial solid waste can be used as a convenient source of advanced oxidation process (AOPs) materials.