Individualism and collectivism

Über die Adsorption in Lösungen

I .. Rates of ionic mass transfer at nickel electrodes rotating about their axes In the center of stationary electrodes were studied using the ferri-ferrocyanide oouple In alkaline solutions. A general mass transfer correlation was found to apply equally well to the dissolution rates of rotating solids and to the rates of ionlo mass transfer at rotating electrodes. This correlation takes into account the physioal properties of the system as well as geometric and hydro dynamic factors. The correlation enables the prediction of limiting currents and concentration polarisation at rotating electrodes under a wide range of conditions. The nature of the polarisation involved in the reduotion of Fe(CNfe~» and the oxidation of Fe(CN#* was also Investigated. The polarisation was found to depend strongly on the presence of "electrode poisons." With freshly prepared solutions, under exclusion of light and with eathodlcally treated nickel electrodes relatively small ehesdcal polarisations were determined. For rotational speeds not exceeding Reynolds number 11,000, the chemical polarisation was found to be negligicle in comparison with the concentration polarisation* Under such conditions the ferro-ferrioyanide oouple can be conveniently used to obtain mass transfer rates for various hydrodynamic conditions, or, conversely, to verify the validity of mass transfer equations by a comparison of experimental .and calculated values of limiting currents and concentration polarisation. The rotating electrode model was found to be most suitable for studying the nature of eleotrolytio polarisation phenomena on aocount of the uniformity of the current distribution as well as of the hydrodynamio diffusion laver at the electrode surfsee.

Mass transfer in electrode processes. 3. ionic mass transfer and concentration polarization at rotating electrodes

Promising evolution of biofuel generations. Subject review

Pyrolysis of polypropylene (PP) and high density polyethylene (HDPE) into fuel like products was investigated over temperature range of 250– 400°C. The product yields as a function of temperature were studied. Total conversion as high as 98.66% (liquid; 69.82%, gas; 28.84%, and residue; 1.34%) was achieved at 300°C in case of PP and 98.12% (liquid; 80.88%, gas; 17.24%, and residue; 1.88%) in case of HDPE at 350°C. The liquid fractions were analyzed by FTIR and GC-MS. The results showed that the liquid fractions consisted of a wide range of hydrocarbons mainly distributed within the C6–C16. The liquid product obtained in case of PP is enriched in the naphtha range hydrocarbons. Similarly, the liquid product obtained in case of HDPE is also enriched in naphtha range hydrocarbons with preponderance in gasoline and diesel range hydrocarbons. The% distribution of paraffinic, olefinic, and naphthenic hydrocarbons in liquid product derived from PP is 66.55, 25.7, and 7.58%, respectively, whereas in case HDPE, th...

Pyrolysis Study of Polypropylene and Polyethylene Into Premium Oil Products

Biodiesel production by esterification of oleic acid over zeolite Y prepared from kaolin

Biodiesel from batch and continuous oleic acid esterification using zeolite catalysts

High purity FAU-type zeolite catalysts from shale rock for biodiesel production

A manganese dioxide (MnO2) electrode on graphite substrate was prepared, characterized, and used for the degradation of phenolic wastewater by an electrochemical advanced oxidation process. The prepared electrode was characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscopy, energy dispersive spectroscopy, and atomic forced microscopy. The deposited material consisted mainly ofγ-MnO2with an average crystal size of 14.3 nm. Some cracks were observed on the surface, and their sizes were measured. Application of the prepared electrode in wastewater remediation by electro-Fenton process was investigated. The effects of the operating conditions, namely, temperature (30–60 °C), current density (2–8 mAcm−2), ferrous iron concentration (0.05–0.4 Mm), and time (1–6 h), were studied. Notably, chemical oxygen demand (COD) removal from wastewater increased significantly with increasing values of the operating parameters. After 6 h, it was found that 88.01% of the initial COD reduced when the solution treated by applying 8 mAcm−2 at 60 °C and 0.4 mM Fe2+. The energetic parameters and kinetics of COD degradation were also investigated.

Oxidative degradation of phenolic wastewater by electro-fenton process using MnO2-graphite electrode

The effect of electrolysis operating parameters on the removal efficiency of cadmium from a simulated wastewater was studied by adopting response surface methodology combined with Box–Behnken Design. As a new electrode design, spiral-wound woven wire mesh rotating cylinder electrode was used for cadmium removal. Current (240–400 mA), rotation speed (200–1000 rpm), initial cadmium concentration (200–600ppm), and cathode mesh number (30–60) were chosen as independent variables while the removal efficiency of cadmium was considered as a response function. The results revealed that the rotation speed has the major effect on the removal efficiency of cadmium. Regression analysis showed good fit of the experimental data to the second-order polynomial model with a coefficient of determination (R2) value of 0.9931 and Fisher F-value of 89.82. The optimal conditions within the experimental ranges of the independent variables were a current of 345 mA, a rotation speed of 800 rpm, an initial cadmium concentration of 500 ppm, and a mesh number of 30, where concentration of cadmium was diminished from 500 to 8 ppm after 60 min of electrolysis with a specific energy consumption of 3.12 kWh kg−1 and a current efficiency of 41%.

Ammar S. Abbas

Papers

Biodiesel production by esterification of oleic acid over zeolite Y prepared from kaolin

Biodiesel from batch and continuous oleic acid esterification using zeolite catalysts

High purity FAU-type zeolite catalysts from shale rock for biodiesel production

Oxidative degradation of phenolic wastewater by electro-fenton process using MnO2-graphite electrode

Cadmium removal using a spiral-wound woven wire meshes packed bed rotating cylinder electrode