Precipitator, fluid electrode

Fluid Electrode Precipitator. In general, the best way to remove fine dust from an air stream is to use conventional electrostatic precipitators. Although the efficiencies of these devices are quite high, there are inherent drawbacks that do not make them acceptable in continuously operating air systems. The collection plates eventually become saturated with the deposited... 

Efficiency of Typical Fluid Electrode Precipitator Configuration... 

Bergstrom et al. [63] used HPLC for determination of penicillamine in body fluids. Proteins were precipitated from plasma and hemolyzed blood with trichloroacetic acid and metaphosphoric acid, respectively, and, after centrifugation, the supernatant solution was injected into the HPLC system via a 20-pL loop valve. Urine samples were directly injected after dilution with 0.4 M citric acid. Two columns (5 cm x 0.41 cm and 30 cm x 0.41 cm) packed with Zipax SCX (30 pm) were used as the guard and analytical columns, respectively. The mobile phase (2.5 mL/min) was deoxygenated 0.03 M citric acid-0.01 M Na2HP04 buffer, and use was made of an electrochemical detector equipped with a three-electrode thin-layer cell. The method was selective and sensitive for mercapto-compounds. Recoveries of penicillamine averaged 101% from plasma and 107% from urine, with coefficients of variation equal to 3.68 and 4.25%, respectively. The limits of detection for penicillamine were 0.5 pm and 3 pm in plasma and in urine, respectively. This method is selective and sensitive for sulfhydryl compounds. 

The limiting current density is an important parameter for the analysis of mass transfer controlled electrochemical processes and represents the maximum possible reaction rate for a given bulk reactant concentration and fluid flow pattern. During anodic metal dissolution, a mass transfer limiting current does not exist because the surface concentration of the dissolving ion (e.g., Cu + when the anode is composed of copper metal) increases with increasing current density, eventually leading to salt precipitation that blocks the electrode surface. 

The treatment was capable of mobilizing Ca and Mg to a considerable extent, promoting migration mainly toward the cathode, where periodic renewal of the process fluid and mechanical cleaning of the electrode from precipitates were required. The precipitates removed from the cathode were analyzed for Ca, Mg, and heavy metal contents. Appreciable removal of heavy metals was achieved and, in this case, appreciable portions of these were also found in the precipitate. 

At the end of each test the pH of the hot fluid was measured immediately using a pH meter and combination electrode which had been calibrated up to pH 10. The meter automatically corrected for temperature, giving equivalent readings for solutions at 25°C. The pH was observed to fall slightly during the time it took to take these measurements, presumably due to contamination from atmospheric CO2 and the subsequent precipitation of calcite, and so the measured pH values are likely to be lower than the true values. The solids were then filtered, dried and analysed by XRD, SEM and ATEM. The fluids were analysed by atomic absorption spectrophotometry (AAS) for Ca, Mg, Fe, Na... 

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