Centro de Investigación y Desarrollo Tecnológico en Electroquímica

About: Centro de Investigación y Desarrollo Tecnológico en Electroquímica is a based out in . It is known for research contribution in the topics: Cyclic voltammetry & Catalysis. The organization has 537 authors who have published 682 publications receiving 10382 citations. The organization is also known as: Centro de Investigacion y Desarrollo Tecnologico en Electroquimica & Center of Research and Technologic Development in Electrochemistry.

Iron precursor salt effect on the generation of OH radicals and sulfamethoxazole degradation through a heterogeneous Fenton process using Carbon-Fe catalysts

Abstract: The influence of the iron precursor salt on the preparation of Carbon-Fe catalysts was evaluated based on the generation of OH radicals in a heterogeneous Fenton process applied to the degradation of sulfamethoxazole (SMX). Carbon catalysts were obtained with 9% Fe by weight using three iron salts: iron acetate (C-AC-AFe), iron sulfate (C-AC-SFe) and iron nitrate (C-AC-NFe). Characterization of catalysts was evaluated by N2 physisorption, X-ray diffraction, scanning electron microscopy and spectroscopic techniques (FTIR, EDX, XPS); these properties were related to the OH generation kinetics and to SMX degradation rate. The iron precursor salt favors the anchoring of the metal in different oxidation state on the catalyst in a proportion of: Fe2+ / Fe3+ = 4.1 for C-AC-AFe, 1.5 for C-AC-SFe and 1.7 for C-AC-NFe, which is related to the OH generated: 53.8 μM g−1, 37.9 μM g−1 and 42.4 μM g−1, respectively. The OH generation kinetics were described by a pseudo-first-order model with rate constants of 0.0252 and 0.0299 min−1 for C-AC-AFe and C-AC-SFe respectively, which coincide with the kinetic constants for the degradation of SMX (0.0262 and 0.0297 min−1), therefore, the oxidation process is carried out by OH. In the case of C-AC-NFe, Fe was fixed within the texture of the carbon and the OH generation was the lowest (0.0005 min−1), explaining the reaction is limited by diffusion. For SMX, the degradation percentage achieved for 20 mg L−1 was: 98.2 % in 120 min for C-AC-AFe, 98.1 % in 180 min for C-AC-SFe and 92.8 % in 210 min for C-AC-NFe.

Optimized Production of a Redox Metabolite (pyocyanin) by Pseudomonas aeruginosa NEJ01R Using a Maize By-Product.

Abstract: Pseudomonas aeruginosa metabolizes pyocyanin, a redox molecule related to diverse biological activities. Culture conditions for the production of pyocyanin in a defined medium were optimized using a statistical design and response surface methodology. The obtained conditions were replicated using as substrate an alkaline residual liquid of cooked maize and its by-products. The untreated effluent (raw nejayote, RN) was processed to obtain a fraction without insoluble solids (clarified fraction, CL), then separated by a 30 kDa membrane where two fractions, namely, retentate (RE) and filtered (FI), were obtained. Optimal conditions in the defined medium were 29.6 °C, 223.7 rpm and pH = 6.92, which produced 2.21 μg mL-1 of pyocyanin, and by using the wastewater, it was possible to obtain 3.25 μg mL-1 of pyocyanin in the retentate fraction at 40 h. The retentate fraction presented the highest concentration of total solids related to the maximum concentration of pyocyanin (PYO) obtained. The pyocyanin redox behavior was analyzed using electrochemical techniques. In this way, valorization of lime-cooked maize wastewater (nejayote) used as a substrate was demonstrated in the production of a value-added compound, such as pyocyanin, a redox metabolite of Pseudomonas aeruginosa NEJ01R.