Walter Torres

Electrochemical degradation of p-substituted phenols of industrial interest on Pt electrodes. Attempt of a structure-reactivity relationship assessment

The electrochemical oxidation of p-substituted phenols, with both electron donor (OH- and NH2-) and electron withdrawing groups (NO2-, COOH-, and halogens), on Pt anodes using sodium sulfate as support electrolyte has been studied. It was found that, except for p-halogen phenols, compounds with electron donor substituents are easier to remove and their initial rates of degradation are correlated to the octanol-water partitioning coefficient (log Poct) and the Hammetts constant. Degradation of all of our starting compounds produced the same intermediates, therefore, a general pathway of reaction is proposed. Additionally, the influence of pH, temperature, electrolyte concentration and current density on the initial and total degradation of p-chlorophenol was also investigated.

Electrochemical treatment of industrial wastewater containing 5-amino-6-methyl-2-benzimidazolone: toward an electrochemical–biological coupling

We studied the electrochemical oxidation, on Pt anodes, of industrial wastewaters containing 5-amino-6-methyl-2-benzimidazolone (AMBI). Electrolysis of this non-biodegradable effluent produces simultaneous oxidation of AMBI and chloride ions. Highly oxidative chlorine intermediate species further boost the degradation of AMBI. Solution temperature, pH and current density affect little the degradation of AMBI. At our best conditions, AMBI was 100% degraded in 45 min. However, because the reaction intermediates exhibited high toxicity and non-biodegradability, the electrolysis had to continue for 3 more hours in order to obtain a biocompatible solution. Then, complete mineralization of the outputs from the electrolytic cells was readily achieved in a fixed bed biological reactor.

Electrochemical degradation of p-substituted phenols of industrial interest on Pt electrodes.

The electrochemical oxidation of p-substituted phenols, with both electron donor (OH- and NH2-) and electron withdrawing groups (NO2-, COOH-, and halogens), on Pt anodes using sodium sulfate as support electrolyte has been studied. It was found that, except for p-halogen phenols, compounds with electron donor substituents are easier to remove and their initial rates of degradation are correlated to the octanol-water partitioning coefficient (log Poct) and the Hammetts constant. Degradation of all of our starting compounds produced the same intermediates, therefore, a general pathway of reaction is proposed. Additionally, the influence of pH, temperature, electrolyte concentration and current density on the initial and total degradation of p-chlorophenol was also investigated.

Extracción y purificación de la enzima monóxido de carbono deshidrogenasa a partir de la bacteria carboxidótrofa Oligotropha carboxidovorans

This paper reports the extraction and purification of the carbon monoxide dehydrogenase enzyme from the Oligotropha carboxidovorans bacteria, OM 5 strain. The bacteria grew autotrophically in a mineral medium, in carbon monoxide saturated atmosphere, at 30°C with constant agitation. In order to obtain the crude enzymatic extracts, the crops underwent a breakdown by sonication, solvolysis with non-ionic detergent and centrifugation to eliminate the cellular debris. During the purification process, the crude enzymatic extracts were passed through a molecular exclusion column as well as through an ion-exchange one.

Electrochemical degradation of p-substituted phenols of industrial interest on Pt electrodes. Structure-electroreactivity relationschips

The electrochemical oxidation of p-substituted phenols, with both electron donor (OH- and NH2-) and electron withdrawing groups (NO2-, COOH-, and halogens), on Pt anodes using sodium sulfate as support electrolyte has been studied. It was found that, except for p-halogen phenols, compounds with electron donor substituents are easier to remove and their initial rates of degradation are correlated to the octanol-water partitioning coefficient (log Poct) and the Hammetts constant. Degradation of all of our starting compounds produced the same intermediates, therefore, a general pathway of reaction is proposed. Additionally, the influence of pH, temperature, electrolyte concentration and current density on the initial and total degradation of p-chlorophenol was also investigated.