The use of Ebonex electrodes for the electrochemical removal of nitrate ion from water

2012 ◽  
Vol 90 (8) ◽  
pp. 666-674 ◽  
Author(s):  
David Kearney ◽  
Dorin Bejan ◽  
Nigel J. Bunce
Keyword(s):  
Titanium Oxide ◽  
Chloride Ion ◽  
Water Sources ◽  
Contaminated Water ◽  
Oxide Ceramic ◽  
Reduction Step ◽  
Nitrate Ion ◽  
Wide Range ◽  
Electrochemical Removal ◽  
Potential Stability

This work addresses the remediation of nitrate-contaminated water using electrodes made of Ebonex (a titanium oxide ceramic with a wide range of potential stability). The objective was the complete denitrification of solutions containing nitrate ion. Denitrification was achieved in about 50% yield with unreactive supporting electrolytes when Ebonex was used as both cathode and anode, the remaining product being ammonia. Ammonia could be re-oxidized at the Ebonex anode, but this was much less efficient than the reduction step. A more efficient electrolytic denitrification was possible for solutions containing chloride; this is oxidized anodically to hypochlorite, which then oxidizes ammonia chemically to N2. The overall rate of denitrification was highest at moderate concentrations of chloride ion, because hypochlorite also re-oxidizes reduction intermediates such as nitrite back to nitrate. Complete denitrification was achieved at all stages of the reaction using Ebonex cathode and a dimensionally stable anode based on Ti/IrO2 or Ti/RuO2, because the DSA oxidizes chloride ion more efficiently than Ebonex. Cathode fouling by water sources that are high in hardness cations can be prevented by using one DSA and a pair of Ebonex electrodes that undergo periodic polarity reversal.

Capturing Cd(ii) and Pb(ii) from contaminated water sources by electro-deposition on hydrotalcite-like compounds

2016 ◽  
Vol 18 (3) ◽  
pp. 1838-1845 ◽  
Author(s):  
M. A. González ◽  
R. Trócoli ◽  
I. Pavlovic ◽  
C. Barriga ◽  
F. La Mantia
Keyword(s):  
Aqueous Solutions ◽  
Water Sources ◽  
Contaminated Water ◽  
Electro Deposition ◽  
Potential Applications ◽  
Toxic Pollutant ◽  
Electrochemical Removal

Two different hydrotalcite-like compounds were prepared and used as substrates for the electrochemical removal of extremely toxic pollutant cations, such as Cd(ii) and Pb(ii), from aqueous solutions, and their posterior recovery for further potential applications.

Preparation of Chloride Ion Selective Electrode and its Potential Response to Different Chloride Solutions Representing Concrete Environments

2011 ◽  
Vol 675-677 ◽  
pp. 537-540 ◽  
Author(s):  
Xiao Jian Gao ◽  
Jian Zhang ◽  
Ying Zi Yang ◽  
Shuang Lu
Keyword(s):  
Current Density ◽  
Pore Solution ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Sodium Ion ◽  
Linear Potential ◽  
Potential Response ◽  
Selective Electrode ◽  
Wide Range ◽  
Potential Stability

Ag/AgCl electrode was made from anodized Ag wire and the influence of anodization current density on stability of Ag/AgCl electrode was studied in this paper. Potential response of Ag/AgCl electrode was tested in synthetic concrete pore solutions with different concentrations of chloride ions and influences of sulfate, calcium, potassium and sodium ion on the potential response of Ag/AgCl electrode were also measured. The results show that Ag/AgCl electrode has the best potential stability when it is prepared with 0.4 mA/m2 of current density for 2 hours and there is no measurable potential difference among 20 electrodes prepared with such anodizing condition. The potential of Ag/AgCl electrode develops to a constant value in less than 60 seconds and maintains stable during the test period when immersed into synthetic concrete pore solution with different amount of chlorides. Ag/AgCl electrode shows a good linear potential response to a wide range of chloride concentrations from 0.005 to 1.0 M. Sulfate, calcium and sodium ions show inconsiderable influences on the potential of Ag/AgCl electrode. Therefore, it is suggested that Ag/AgCl electrodes can be used as chloride sensors in concrete exposed to different environments.

Brief history and ways of further development of the department of hydraulic engineering and hydraulics FSBI «VNIIGiM named after A.N. Kostyakov»

2020 ◽  
pp. 18-23
Author(s):  
Alexey Shcherbakov ◽  
Valentin Zhezmer
Keyword(s):  
Land Reclamation ◽  
Water Source ◽  
Water Sources ◽  
Hydraulic Engineering ◽  
Negative Effects ◽  
Extensive Experience ◽  
Safety Level ◽  
Theoretical Substantiation ◽  
Wide Range ◽  
Construction Operation

Department of hydraulic engineering and hydraulics FGBNU «VNIIGiM them. A.N. Kostyakova «has a long history. For many years, the department’s staff has been such scientists and water engineers with extensive experience as M.A. Volynov, V.S. Verbitsky, S.S. Medvedev, N.V. Lebedev, B.C. Panfilov, T.G. Voynich-Syanozhentsky, V.A. Golubkova, G.V. Lyapin and others. The department solved a wide range of tasks, the main areas of research were the following: – theoretical and applied hydrodynamics and hydraulics, with reference to the open channel flows that affect the state and level of safety of the hydraulic structures; – integrated use and protection of water bodies – water sources and water sources of water resources used in land reclamation; – development of measures and technical solutions for the protection of objects from the negative effects of water; – theoretical substantiation of works to improve the safety level of the GTS (declaration); – development and implementation of digitalization methods for solving design, construction, operation and control of landreclamation facilities. Currently, promising areas of research is the development of a decision-making algorithm in the designation of measures to rationalize the provision of resources to water amelioration. The algorithm is developed on the basis of a detailed study, systematization and processing of data both on safety and on the efficiency of systems and structures, ensuring the delivery of irrigation water of the required quality and in sufficient quantity from a water source to the field.

scholarly journals Sequential Oxidation on Wood and Its Application in Pb2+ Removal from Contaminated Water

2021 ◽  
Vol 2 (2) ◽  
pp. 245-256
Author(s):  
Priyanka R. Sharma ◽  
Sunil K. Sharma ◽  
Marc Nolan ◽  
Wenqi Li ◽  
Lakshta Kundal ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Average Length ◽  
Sodium Chlorite ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Fiber Morphology ◽  
Carboxylate Groups ◽  
Carboxylate Content ◽  
Wide Range ◽  
Length Width

Raw wood was subjected to sequential oxidation to produce 2,3,6-tricarboxycellulose (TCC) nanofibers with a high surficial charge of 1.14 mmol/g in the form of carboxylate groups. Three oxidation steps, including nitro-oxidation, periodate, and sodium chlorite oxidation, were successfully applied to generate TCC nanofibers from raw wood. The morphology of extracted TCC nanofibers measured using TEM and AFM indicated the average length, width, and thickness were in the range of 750 ± 110, 4.5 ± 1.8, and 1.23 nm, respectively. Due to high negative surficial charges on TCC, it was studied for its absorption capabilities against Pb2+ ions. The remediation results indicated that a low concentration of TCC nanofibers (0.02 wt%) was able to remove a wide range of Pb2+ ion impurities from 5–250 ppm with an efficiency between 709–99%, whereby the maximum adsorption capacity (Qm) was 1569 mg/g with R2 0.69531 calculated from Langmuir fitting. It was observed that the high adsorption capacity of TCC nanofibers was due to the collective effect of adsorption and precipitation confirmed by the FTIR and SEM/EDS analysis. The high carboxylate content and fiber morphology of TCC has enabled it as an excellent substrate to remove Pb2+ ions impurities.

scholarly journals Novel magnetic core-shell nanoparticles for the removal of polychlorinated biphenyls from contaminated water sources

2019 ◽  
Vol 223 ◽  
pp. 68-74 ◽  
Author(s):  
Angela M. Gutierrez ◽  
Rohit Bhandari ◽  
Jiaying Weng ◽  
Arnold Stromberg ◽  
Thomas D. Dziubla ◽  
...  
Keyword(s):  
Polychlorinated Biphenyls ◽  
Magnetic Core ◽  
Water Sources ◽  
Core Shell ◽  
Contaminated Water ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Validation of Surface Temperature Measurements on a Combustor Liner Under Full-Load Conditions Using a Novel Thermal History Paint

2016 ◽  
Author(s):  
Robert Krewinkel ◽  
Jens Färber ◽  
Martin Lauer ◽  
Dirk Frank ◽  
Ulrich Orth ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal History ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Lanthanide Ions ◽  
Maximum Temperature ◽  
Oxide Ceramic ◽  
Ambient Conditions ◽  
Hot Gas ◽  
Wide Range

The ever-increasing requirements on gas turbine efficiency, which are at least partially met by increasing firing temperatures, and the simultaneous demand for reduced emissions, necessitate much more accurate calculations of the combustion process and combustor wall temperatures. Thermocouples give locally very accurate measurements of these temperatures, but there is a practical limit to the amount of measurement points. Thermal paints are another established measurement technique, but are toxic and at the same time require dedicated, short-duration tests. Thermal History Paints (THPs) provide an innovative alternative to the aforementioned techniques, but so far only a limited number of tests has been conducted under real engine conditions. THPs are similar in their chemical and physical make-up to conventional thermographic phosphors which have been successfully used in gas turbine applications for on-line temperature detection before. A typical THP comprises of oxide ceramic pigments and a water based binder. The ceramic is synthesized to be amorphous and when heated it crystallizes, permanently changing the microstructure. The ceramic is doped with lanthanide ions to make it phosphorescent. The lanthanide ions act as atomic level sensors and as the structure of the material changes, so do the phosphorescent properties of the material. By measuring the phosphorescence the maximum temperature of exposure can be determined through calibration, enabling post operation measurements at ambient conditions. This paper describes a test in which THP was applied to an impingement-cooled front panel from a combustor of an industrial gas turbine. Since this component sees a wide range of temperatures, it is ideally suited for the testing of the measurement techniques under real engine conditions. The panel was instrumented with a thermocouple and thermal paint was applied to the cold side of the impingement plate. THP was applied to the hot-gas side of this plate for validation against the other measurement techniques and to evaluate its resilience against the reacting hot gas environment. The durability and temperature results of the three different measurement techniques are discussed. The results demonstrate the benefits of THPs as a new temperature profiling technique. It is shown that the THP exhibited greater durability compared to the conventional thermal paint. Furthermore, the new technology provided detailed measurements down to millimeters indicating local temperature variations and global variations over the complete component.

scholarly journals Melamine-based functionalized graphene oxide and zirconium phosphate for high performance removal of mercury and lead ions from water

RSC Advances ◽  
2020 ◽  
Vol 10 (62) ◽  
pp. 37883-37897
Author(s):  
Ayyob M. Bakry ◽  
Fathi S. Awad ◽  
Julian A. Bobb ◽  
Amr A. Ibrahim ◽  
M. Samy El-Shall
Keyword(s):  
Graphene Oxide ◽  
High Performance ◽  
Zirconium Phosphate ◽  
Selective Extraction ◽  
Water Sources ◽  
Lead Ions ◽  
Contaminated Water ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide

Two novel chelating adsorbents are developed for the effective and selective extraction of Hg(ii) and Pb(ii) ions from contaminated water sources.

scholarly journals Selected Properties Of Thermally Sprayed Oxide Ceramic Coatings

2015 ◽  
Vol 15 (3) ◽  
pp. 17-32 ◽  
Author(s):  
A. Czupryński
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Calcium Oxide ◽  
Zirconium Oxide ◽  
Steel Substrate ◽  
Ceramic Coatings ◽  
Abrasive Wear Resistance ◽  
Flame Spraying ◽  
Oxide Ceramic ◽  
Wide Range

Abstract The article presents the results of the study on exploitation properties of flame sprayed ceramic coatings produced by oxide ceramic material in the form of powder on the aluminum oxide Al2O3 matrix with 3% titanium oxide TiO2 addition and also on the zirconium oxide (ZrO2) matrix with 30% calcium oxide (CaO) on the substrate of unalloyed structural steel of S235JR grade. As a primer powder, metallic powder on the base of Ni-Al-Mo has been applied. Plates with dimensions of 5×200×300 mm and also front surfaces of ∅40×50 mm cylinders have been flame sprayed. Spraying of primer coating has been done using RotoTec 80 torch and external specific coating has been done with CastoDyn DS 8000 torch. Investigations of coating properties are based on metallography tests, phase composition research, measurement of microhardness, coating adhesion to the ground research (acc. to EN 582:1996 standard), abrasive wear resistance (acc. to ASTM G65 standard) and erosion wear resistance (acc. to ASTM G76-95 standard) and thermal stroke study. Performed tests have shown that the flame spraying with 97%Al2O3 powder containing 3% TiO2 and also by the powder based on zirconium oxide (ZrO2) containing 30% calcium oxide (CaO) performed in a wide range of technological parameters allow to obtain high quality ceramic coatings with thickness up to ca. 500 μm on a steel substrate. The primer coating sprayed with the Ni-Al-Mo powder to the steel substrate and external coatings sprayed has the of mechanical bonding character. The coatings are characterized by high adhesion to the substrate and also high erosion and abrasive wear resistance and the resistance for cyclic thermal stroke.

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