Oxidation Of Other Substances Research Articles

Relationship between oxide identity and electrocatalytic activity of platinum for ethanol electrooxidation in perchlorate acidic solution

Water and its dissociated species at the solid‒liquid interface play critical roles in catalytic science; e.g., functions of oxygen species from water dissociation are gradually being recognized. Herein, the relationship between oxide identity (PtOHads, PtOads, and PtO2) and electrocatalytic activity of platinum for ethanol electrooxidation was obtained in perchlorate acidic solution over a wide potential range with an upper potential of 1.5 V (reversible hydrogen electrode, RHE). PtOHads and α-PtO2, rather than PtOads, act as catalytic centers promoting ethanol electrooxidation. This relationship was corroborated on Pt(111), Pt(110), and Pt(100) electrodes, respectively. A reaction mechanism of ethanol electrooxidation was developed with DFT calculations, in which platinum oxides-mediated dehydrogenation and hydrated reaction intermediate, geminal diol, can perfectly explain experimental results, including pH dependence of product selectivity and more active α-PtO2 than PtOHads. This work can be generalized to the oxidation of other substances on other metal/alloy electrodes in energy conversion and electrochemical syntheses.

Carbon coated titanium electrode for the electrolytic decoloration of methylene blue

Electrolysis is widely adopted in water treatment. The major challenge of electrolysis technology focuses on developing better electrode materials. In this study, we reported that the hydrothermal coating of titanium electrode with carbon (C-Ti electrode) could significantly improve the decoloration performance of Ti electrode. The decoloration kinetics of C-Ti electrode was much faster than that of naked Ti electrode at the same current density. The presence of chloride electrolytes, e.g. NaCl and KCl, was crucial for the efficient electrolysis. The optimized pH for C-Ti electrode was pH 7. Beyond methylene blue, C-Ti electrode showed high decoloration performance for other dyes, such as congo red, acidic blue 92 and remazol brilliant blue R. Mechanistically, the electrolytic oxidation of MB was mainly via indirect pathway, where Cl− was oxidized into ClO− for the oxidation of other substances. Moreover, the performance of C-Ti electrode largely remained in the recycling evaluations. The implication to the applications of C-Ti electrode in water treatment is discussed.

Biodegradation Phenomena during Soil Vapor Extraction. III. Sensitivity Studies for Two Substrates

Abstract In the bioventing technique, soil vapor extraction (SVE) is used to promote aerobic biodegradation of contaminants in the vadose zone. Kinetics limited by mass transport of the contaminant and/or oxygen through the aqueous phase to the microorganisms and of contaminant to the gaseous phase may be expected during field operation. Sensitivity studies were performed with a one-dimension model for two substrates showing competitive inhibition, following Monod's kinetics. The mass transfer limitations were represented by means of lumped parameters, and results for high and low values of these parameters were compared. Under kinetics severely limited by mass transport processes, biodegradation occurs at a rate given by the availability of dissolved oxygen, and important contributions of biological degradation to the overall cleanup are expected if oxygen is not utilized exclusively for the oxidation of other substances than the target contaminant. For relatively fast mass transport kinetics the system ...

The biological oxidation of synthetic detergents in recirculating filters

The principle methods of determing the biodegradability of synthetic detergents is reviewed. Experimental work is described in which the degradability of a detergent may be determined by recirculating it in an inoculated solution containing nutrient salts through a column of gravel or a similar inert filtering medium. If the detergent is decomposable by bacteria these rapidly colonize the gravel. The filter reaches its maximum efficiency in a few days and thereafter may continue to be used indefinitely. Most of the paper is devoted to an account of the exploitation of this technique. It is shown, for example, that almost 100 per cent oxidation can be achieved with one of the non-ionic detergents and an anionic detergent within 24 hr. The recirculation filters can be inoculated with a mixture of anionic and non-ionic detergents of different molecular structure, thus increasing the likelihood that organisms are present within the filters able to attack many of the molecular groups contained in synthetic detergents. This method of studying the decomposition of detergent suggest the possibility of following the rate of oxidation of other substances, such as those present in industrial waste waters.

THE FOOD VALUE OF ALCOHOL.

The question whether alcohol is a food or not will be answered in accordance with the individual point of view, especially as to the definition of what constitutes a food. Some argue that if, after ingestion, it is oxidized in the tissues, entering into their formation and repair and giving rise to heat and energy, it must be considered a food, whereas, if it be excreted unchanged, it can not be thus classified. Different observers have reached divergent conclusions on the subject, and the explanation must be looked for, in part at least, in differences in method, and in part also in differences in conception of the character of a food. It has been shown that alcohol is oxidized in the animal body, although, at the same time, it interferes with metabolism or oxidation of other substances, as indicated by lessened absorption of oxygen, decline in body temperature, degeneration of