6 edition of Assessment of the Electrochemical Reduction of Perchlorate Ion found in the catalog.
by Amer Water Works Assn
Written in English
|The Physical Object|
|Number of Pages||44|
Prior electrochemical studies of the oxidation of ClO − 2 have suggested that it undergoes a diffusion-limited, one-electron oxidation. In , Schwarzer and Landsberg reported that the oxidation of chlorite ion on graphite rotating disk electrode in the pH range produced a current that was proportional to concentration. on perchlorate recoveries throughout the measurable range. Typical recoveries are 90%–% at the and 1-ppb level in synthetic drinking and waste waters with the method detection limit (MDL) less than ppt. The Analysis of Perchlorate by Ion Chromatography/Mass Spectrometry Application Introduction Perchlorate is commonly used as an.
The Perchlorate Ion-Selective Electrode has a solid-state PVC polymer matrix membrane. The electrode is designed for the detection of perchlorate ions (ClO 4-) in aqueous solutions and is suitable for use in both field and laboratory applications. The Perchlorate Ion . This book summarizes the most current knowledge and understandings of the extent and potential sources of perchlorate contamination, its behavior, exposure pathways in the environment, toxicology and risk assessment, and recent advances in treatment technologies for removing perchlorate from contaminated soil and water.
Electrochemical cells that use an oxidation-reduction reaction to generate an electric current are known as galvanic or voltaic cells. Because the potential of these cells to do work by driving an electric current through a wire is measured in units of volts, we will refer to the cells that generate this potential from now on as voltaic cells. of perchlorate ion formation. At the lowest temperature of 30°C, this resulted in incubation times of at least days (half-life = 65 days at 30°C). To calculate the rates of perchlorate ion formation, the changes in measured concentration of perchlorate ion were divided by the incubation intervals. To determine the reaction order with.
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Perchlorate can be effectively removed by wide variety of remediation techniques such as bio-reduction, chemical reduction, adsorption, membrane filtration, ion exchange and electro-reduction.
Unlike sorption- or membrane-based approaches, electrochemical treatment permanently converts the perchlorate into harmless species. Existing approaches such as reverse osmosis, activated Assessment of the Electrochemical Reduction of Perchlorate Ion book, or ion exchange require monitoring and periodic replacement or regeneration as well as subsequent disposal or destruction of perchlorate.
In order to assess the role of platinum in the electrochemical reduction of perchlorate ion, the following experiment was performed. Using a nickel counter electrode in 1 M HClO 4 a potentiostated experiment was carried out at − V with addition of 10 −3 M H 2 PtCl 6 to the working solution.
Analysis of the working solution after electrolysis for 9 h showed that the concentration of Cited by: Indirect electrochemical reduction of perchlorate or nitrate in synthetic single anion solution resulted in the removal of perchlorate and nitrate at 50% in 8 h and 40% in 6 h, respectively.
There was mass imbalance in both chlorine and nitrogen; the total mass accounted for in the simple synthetic solutions was only 86% in 8 h and 81% in 6 h Cited by: The electrochemical and electrophotocatalytic reduction of the perchlorate ion to the chloride ion were assessed at laboratory scale .
The study was carried out in two-chambered batch reactor systems in which the cathodic and anodic compartments were separated by an ion exchange membrane. The requirements for perchlorate reduction in Standard 58 are described in Table 1.
Change Proposal Currently, there is a proposal before the Joint Committee to revise the influent challenge level to mg/L and the maximum allowable product water concentration to mg/L. The mixed perchlorate-reduction bacteria could reduce about 91% of loaded perchlorate ( mg g−1) on MWS in the first biological-reduction cycle and 87% in second cycle, indicating an.
Perchlorate is a widespread, environmentally persistent contaminant recently discovered in U.S. groundwater and drinking water supplies. This book summarizes the most current knowledge and understandings of the extent and potential sources of perchlorate contamination, its behavior, exposure pathways in the environment, toxicology and risk assessment, and recent advances in treatment Reviews: 1.
A fairly unique combination of chemical and physical properties of perchlorate poses challenges to its analysis and reduction in the environment or in drinking water.
The implications of these properties are discussed in terms of remediative or treatment strategies. Recent developments are also covered. information on perchlorate to site managers and other field personnel who are addressing perchlorate contamination at cleanup sites or in drinking water supplies.
Perchlorate is a persistent contaminant of concern that has presented a number of issues to the government, the private sector and other organizations and interested parties. The activation energy (E a) of perchlorate reduction on the Rh-Cu/SS electrode was ± and ± kJ / mol in the temperature range of – K and – K, respectively.
A proposed perchlorate reduction pathway was developed and successfully used to predict the reaction kinetics. No other oxyanions of chlorine, such as ClO. A new heterogeneous catalyst that promotes the reduction by hydrogen of perchlorate ion in water under mild conditions has been developed.
The catalyst is prepared by adsorption of a rhenium(VII) precursor (either ammonium perrhenate or methylrhenium trioxide) onto carbon powder containing 5% palladium by weight. Under standard batch conditions of room temperature, 1 bar of. This book summarizes the most current knowledge and understandings of the extent and potential sources of perchlorate contamination, its behavior, exposure pathways in the environment, toxicology and risk assessment, and recent advances in treatment technologies for removing perchlorate.
A perchlorate is a chemical compound containing the perchlorate ion, ClO − majority of perchlorates are commercially produced salts. They are mainly used for propellants, exploiting properties as powerful oxidizing agents and to control static electricity in food packaging.
Perchlorate contamination in food, water, and other parts of the environment has been studied in the U.S. because. Electrochemical Reduction of Perchlorate Perchlorate Risk Assessment Recent Advances in Ion Exchange for Perchlorate Treatment.
Recovery and. Despite favorable thermodynamics, the reduction of perchlorate (ClO4-) is kinetically limited in aqueous media because of its high activation energy. In this paper, a new methodology has been presented for degrading ClO4- in an FeCl3−HCl solution at an elevated temperature.
the reduction of perchlorate: ClO 4 þ 4Fe 0 þ8Hþ. Cl þ 4Fe2þ þ 4H 2O DG ¼ 1; kJ=mol ð2Þ However, only one research has reported rather slow removal of aqueous perchlorate under ambi-ent temperature (Moore, et al., ).
Little or no perchlorate reduction by zero-valent iron was observed in several other studies (Espenson, ). Electrochemical reaction, any process either caused or accompanied by the passage of an electric current and involving in most cases the transfer of electrons between two substances—one a solid and the other a liquid.
Under ordinary conditions, the occurrence of a chemical reaction is accompanied. Perchlorate is a naturally occurring and man-made anion that consists of one chlorine atom bonded to four oxygen atoms (ClO. 4-). Manufactured forms of perchlorate include perchloric acid and salts such as ammonium perchlorate, sodium perchlorate and potassium perchlorate.
Unfortunately, it was found that the perchlorate ion, an extremely stable species, could not be decomposed by means of electrochemical reduction at a practical rate in tap water. The research project goal then was refocused to the selective, chemical-free purification of perchlorate.
1. Acta Chim Slov. ;61(2) Electrochemical reduction of perchlorate ions on ruthenium. Láng GG, Ujvári M, Vesztergom S. The reduction of perchlorate ions at ruthenium electrodes was investigated by voltammetry, chronoamperometry, impedance spectroscopy, and by measuring changes of interfacial stress changes using the cantilever bending method as functions of electrode potential.
Lang GG, Sas NS, Ujvari M, Horanyi G () The kinetics of the electrochemical reduction of perchlorate ions on rhodium. Electrochim Acta – Google Scholar Lee C, Kramer T () Electrochemical reduction of perchlorate ions on .The electrochemical reduction of perchlorate ion has been reported for a wide variety of cathodes, in- cluding platinum (Hordnyi and Vertes, b; Vasina and Petrii, ), tungsten carbide (Hordnyi and Vertes,a; Vertes and Horanyi, ), ruthenium (Gonzales Tejera and Colom Polo, ), carbon doped with chromium(III) oxide or.