Search

This study investigated the electrogeneration of Ce(IV) and its application on the destruction of polyvinyl alcohol (PVA) in an undivided electrochemical cell. The effects of electric current, concentration of nitric acid, and temperature on PVA destruction efficiency were investigated and the corresponding specific energy consumptions (SEC) were also evaluated. The experimental results indicate that the PVA destruction increased with increasing the applied current, the concentration of nitric acid, and decreasing the temperature. When considering the PVA destruction efficiency and the corresponding SEC simultaneously, the best operating condition was found by 92% at the optimal applied current 0.1 A, concentration of nitric acid 0.5 M, and temperature 323 K, respectively. A pseudo-first-order kinetic model provided a good fit to the experimental results at various temperatures. The activation energy was calculated to be 78.27 kJ mol−1, based on pseudo-first-order rate constants from the Arrhenius equation. [ABSTRACT FROM PUBLISHER]

This study investigates the effectiveness of using the activated carbon fiber (ACF) cloth electrodes for the reduction of the conductivity from the water with a low NaCl content. The ACF cloth can not reduce the conductivity of the solution by pure adsorption, but shows good effectiveness while charging. Findings show the effectiveness of the ACF electrode does not change significantly after at least ten repeated charging/discharging cycles. The highest reduction degree of conductivity is about 60 %, and the recovery degrees approach almost 100 % in this work. The reduction degree of conductivity increases with increasing the applied voltage and the initial NaCl concentration below 200 ppm. The ACF electrode treated by HNO3 of different concentrations and treatment time possess a lower desalination degree, which decreases with increasing the treatment time and the concentration of HNO3. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the color removal efficiency of Acid Orange 7 by electrochemical oxidation. The operating variables, such as the applied current density, the pH of solution, the temperature of solution, and the concentration of electrolytes, were investigated. Five materials were used to compare their efficiencies for removing the Acid Orange 7. The removal efficiency follows the order: ACF c>ACF b>ACF a>Pt/Ti>graphite. The color removal percentage increased when increasing the applied current density up to 10.0mA/cm2, at which point the color removal rate began to be controlled by mass transfer. Experimental results showed that higher pH and temperature of the solution were beneficial for the removal of Acid Orange 7 and that the Na2SO4 electrolyte concentration did not significantly affect the removal rate. The energy consumption was in the range of 1.178 to 10.44kWh/moldm3, depending on the applied current density. The adsorption and electrooxidation were found to follow first-order kinetics. The best overall rate constant for ACF a was found to be 0.16min−1 at an initial pH of 9.7. The regeneration of ACF anode surface was observed after a 30-min treatment using 10.0mA/cm2. [ABSTRACT FROM AUTHOR]

In this study, the removals of the mercury and methyl mercury by applying an electric field have been investigated. The experimental results show that the non-uniform distributions of the pH, conductivity and potential gradient would be formed during the treatment. These unexpected distributions would slow down the removal of contaminants. Sothe mercury and methyl mercury could be only reduced t about 73.6% and 59.4% utter 100-day treatment, respectively. Thus, the enhancementby sing buffer solutions or canon exchange membranes was conducted to avoid the backing anon of the OH- generated at the cathode. The results show that the removal efficiencies of the mercury could attain 88% or more and that of the methyl mercury could reach to 4% or more after only 60-day treatments by using either buffer solutions or cation exchange a membranes. [ABSTRACT FROM AUTHOR]

The title compound, C(11)H(18)N(2)S(4), was unexpectedly obtained during studies on the reactivity of the complex tris-(acac-κ(2)O,O')gallium(III) (acac is acetyl-acetonate) with C(4)H(8)NCS(2)H in dichloro-methane. The title compound shows disordered two pyrrolidine rings with major and minor occupancies of 0.546 (4) and 0.454 (4). Two (pyrrolidin-1-yl)carbothio-ylsulfanyl units are linked together through a methyl-ene C atom and weak C-H⋯S inter-actions are found.