scholarly journals Impact of the electrochemical treatment on physical and chemical properties of water activated in various devices using electrochemical activation technology

2020 ◽  
Vol 99 (9) ◽  
pp. 904-910
Author(s):  
Larisa P. Nekrasova ◽  
Rufina I. Mikhailova ◽  
Irina N. Ryzhova
Keyword(s):  
Water Treatment ◽  
Water Purification ◽  
Chemical Properties ◽  
Physicochemical Characteristics ◽  
Electrochemical Treatment ◽  
General Term ◽  
Chloride Ions ◽  
Electrochemical Activation ◽  
Modern Approach ◽  
Electrochemically Activated Water

Introduction. Currently, there are various technologies for water treatment and water purification, including ozonation of water, water treatment with UV radiation, ion exchange, magnetization. Electrochemical treatment of water by direct electric current, in which activated water is formed, characterized by many anomalous properties, is a modern approach to water treatment and water treatment. Purpose of the study. The study of the physicochemical properties of water-activated in devices of different manufacturers with different designs. Material and methods. To activate the water, activators were used: AP-1, Melesta, Zdrava, the filter of electrochemical water purification “ Izumrud”. The activity of hydrogen ions and the redox potential of water were measured using an Ecotest-120 ionomer with a switch. To measure the electrical conductivity of the solutions, an Expert-002 conductometer was used. Free chlorine was determined by the photocolorimetric method on a Spectroquant Multy colorimeter. Antioxidant activity was determined spectrophotometrically using a mediator system of potassium ferro-ferricyanide. Results. Chloride ions make a decisive contribution to the change in the physicochemical characteristics of anolyte upon activation of water. Sulfates and bicarbonates do not affect the prooxidant activity of the anolyte. The relaxation of catholytes obtained in membrane activators proceeds by a gradual increase in ORP, while the relaxation of activated water in the Zdrava diaphragmless activator proceeds in an oscillatory mode and is characterized by sharp changes in ORP. Anolytes are stable over time and slightly change the pH and ORP during storage. The activation of certain types of water in a diaphragmless activator does not lead to a decrease in the ORP, but its significant growth. Conclusion. Electrochemically activated water is a general term that hides in each case an unknown substance with an unpredictable effect. The use of standard devices even when using the same water sample, as a rule, leads to different physicochemical characteristics of activated water. When using different types of water, physicochemical characteristics differ significantly. The use of electrochemically activated water is unsafe.

Decomposition of hydrogen peroxide on nickel-silver two-component catalyst

1984 ◽  
Vol 49 (10) ◽  
pp. 2222-2230 ◽  
Author(s):  
Viliam Múčka ◽  
Rostislav Silber
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Properties ◽  
Silver Ions ◽  
Surface Concentration ◽  
Chloride Ions ◽  
Nickel Silver ◽  
Silver Catalysts ◽  
Physico Chemical ◽  
Low Degree ◽  
Defective Crystal

The catalytic and physico-chemical properties of low-temperature nickel-silver catalysts with nickel oxide concentrations up to 43.8% (m/m) are examined via decomposition of hydrogen peroxide in aqueous solution. The mixed catalysts prepared at 250°C are composed of partly decomposed silver carbonate or oxide and nickel carbonate or hydroxide decomposed to a low degree only and exhibiting a very defective crystal structure. The activity of these catalysts is determined by the surface concentration of silver ions, which is affected by the nickel component present. The latter also contributes to the thermal stability of the catalytic centres of the silver component, viz. the Ag+ ions. The concentration of these ions varies with the temperature of the catalyst treatment, the activity varies qualitatively in the same manner, and the system approaches the Ag-NiO composition. The catalytic centres are very susceptible to poisoning by chloride ions. A previous exposition of the catalyst to a gamma dose of 10 kGy from a 60Co source has no measurable effect on the physico-chemical properties of the system.

scholarly journals Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1338 ◽  
Author(s):  
Klara Perović ◽  
Francis M. dela Rosa ◽  
Marin Kovačić ◽  
Hrvoje Kušić ◽  
Urška Lavrenčič Štangar ◽  
...  
Keyword(s):  
Water Treatment ◽  
Transition Metal ◽  
Photocatalytic Degradation ◽  
Water Splitting ◽  
Water Purification ◽  
Degradation Mechanism ◽  
Living Environment ◽  
Solar Irradiation ◽  
Metal Chalcogenides ◽  
Photocatalytic Water Splitting

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H2 production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e−/h+) pairs at a semiconducting material upon its excitation by light with sufficient photon energy. Most of the photocatalytic studies involve the use of TiO2 and well-suited model compounds, either as sacrificial agents or pollutants. However, the wider application of this technology requires the harvesting of a broader spectrum of solar irradiation and the suppression of the recombination of photogenerated charge carriers. These limitations can be overcome by the use of different strategies, among which the focus is put on the creation of heterojunctions with another narrow bandgap semiconductor, which can provide high response in the visible light region. In this review paper, we report the most recent advances in the application of TiO2 based heterojunction (semiconductor-semiconductor) composites for photocatalytic water treatment and water splitting. This review article is subdivided into two major parts, namely Photocatalytic water treatment and Photocatalytic water splitting, to give a thorough examination of all achieved progress. The first part provides an overview on photocatalytic degradation mechanism principles, followed by the most recent applications for photocatalytic degradation and mineralization of contaminants of emerging concern (CEC), such as pharmaceuticals and pesticides with a critical insight into removal mechanism, while the second part focuses on fabrication of TiO2-based heterojunctions with carbon-based materials, transition metal oxides, transition metal chalcogenides, and multiple composites that were made of three or more semiconductor materials for photocatalytic water splitting.

scholarly journals Technosols Development in an Abandoned Mining Area and Environmental Risk Assessment

2021 ◽  
Vol 11 (15) ◽  
pp. 6982
Author(s):  
Chiara Ferronato ◽  
Gilmo Vianello ◽  
Mauro De Feudis ◽  
Livia Vittori Antisari
Keyword(s):  
Central Italy ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Soil Surface ◽  
Mining Area ◽  
Physicochemical Characteristics ◽  
Matter Content ◽  
Mine Tailing ◽  
Inorganic Materials ◽  
Soil Features

The study of Technosols development, spatial distribution and physicochemical characteristics is becoming more and more important in the Anthropocene Era. The aim of the present study was to assess soil features and potential heavy metal release risk of soils developed on different mine tailing types after the waste disposal derived from mining activity in Central Italy. Soils were analyzed for their morphological, physical and chemical properties, and a chemical sequential extraction of heavy metals was performed. The investigated soils were classified as Technosols toxic having in some layer within 50 cm of the soil surface inorganic materials with high concentrations of toxic elements. Our findings showed that the bioavailability of potentially toxic element concentrations in the soil changed according to the origin of the mine tailing. However, because of the acidic pH, there is a serious risk of metals leaching which was reduced where the soil organic matter content was higher.

scholarly journals Microbiological and Chemical Properties of Chokeberry Juice Fermented by Novel Lactic Acid Bacteria with Potential Probiotic Properties during Fermentation at 4 °C for 4 Weeks

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 768
Author(s):  
Christos Bontsidis ◽  
Athanasios Mallouchos ◽  
Antonia Terpou ◽  
Anastasios Nikolaou ◽  
Georgia Batra ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Chemical Properties ◽  
Storage Period ◽  
Probiotic Strain ◽  
Physicochemical Characteristics ◽  
Probiotic Properties ◽  
Acid Fermentation ◽  
Chokeberry Juice ◽  
Fermented Juice

On the frame of this research survey, a novel potentially probiotic strain (Lactobacillus paracasei SP5) recently isolated from kefir grains was evaluated for chokeberry juice fermentation. Chokeberry juice was retrieved from the variety Aronia melanocarpa, a plant known to provide small, dark berries and to be one of the richest sources of antioxidants. The juice was subsequently fermented inoculating L. paracasei SP5 for 48 h at 30 °C. The fermented juices were left at 4 °C and tested regarding microbiological and physicochemical characteristics for 4 weeks. The potentially probiotic strain was proved capable of performing lactic acid fermentation at 30 °C. Cell viability of L. paracasei was detected in high levels during fermentation and the whole storage period, while the fermented juice showed higher levels of viability in juice with 40.3 g/L of initial sugar concentration. No ethanol was detected in the final fermented juice. Fermented chokeberry juice was characterized by aromatic desirable volatiles, which were retained in adequate levels for the whole storage period. Specifically, the occurrence of organic esters detected in fermented juices is considered as positive evidence of the provision of fruity and floral notes to the final product. During storage, total phenolics content and antioxidant activity were observed in higher levels in fermented chokeberry juice compared with non-fermented juice. Subsequently, fermentation of chokeberry juice by potentially probiotic lactic acid bacteria could provide high industrialization potential, providing the market with a nutritional beverage of good volatile quality with an enhanced shelf-life compared with an unfermented fresh juice.

scholarly journals Physicochemical Characteristics of Arginine Enriched NaF Varnish: An In Vitro Study

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2998
Author(s):  
Mohammed Nadeem Bijle ◽  
Manikandan Ekambaram ◽  
Edward Lo ◽  
Cynthia Yiu
Keyword(s):  
Molecular Dynamics ◽  
Physical Properties ◽  
Artificial Saliva ◽  
Chemical Properties ◽  
In Vitro Study ◽  
Physicochemical Characteristics ◽  
Vitro Study ◽  
Physical And Chemical ◽  
Stable Matrix

The in vitro study objectives were to investigate the effect of arginine (Arg) incorporation in a 5% sodium fluoride (NaF) varnish on its physical and chemical properties including F/Arg release. Six experimental formulations were prepared with L-arginine (L-Arg) and L-arginine monohydrochloride at 2%, 4%, and 8% w/v in a 5% NaF varnish, which served as a control. The varnishes were subjected to assessments for adhesion, viscosity, and NaF extraction. Molecular dynamics were simulated to identify post-dynamics total energy for NaF=Arg/Arg>NaF/Arg<NaF concentrations. The Arg/F varnish release profiles were determined in polyacrylic lactate buffer (pH-4.5; 7 days) and artificial saliva (pH-7; 1 h, 24 h, and 12 weeks). Incorporation of L-Arg in NaF varnish significantly influences physical properties ameliorating retention (p < 0.001). L-Arg in NaF varnish institutes the Arg-F complex. Molecular dynamics suggests that NaF>Arg concentration denotes the stabilized environment compared to NaF<Arg (p < 0.001). The 2% Arg-NaF exhibits periodic perennial Arg/F release and shows significantly higher integrated mean F release than NaF (p < 0.001). Incorporating 2% L-arginine in 5% NaF varnish improves its physical properties and renders a stable matrix with enduring higher F/Arg release than control.

Enhancement of Efficiency of the Ural Region Surface Water Sources Water Treatment in Terms of Metal Ions and their Compounds

2012 ◽  
pp. 96-108
Author(s):  
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Metal Ions ◽  
Water Purification ◽  
Solid Phase ◽  
Ural Region ◽  
Iron Aluminum ◽  
High Degree ◽  
Water Hydrogen ◽  
Sorption Characteristics

Sorption characteristics of “Ekozol-401” high-dispersed solid-phase agent in water solutions containing ions of iron, aluminum and manganese have been studied. Influence of the sorbent content, extracted metals’ concentration, saline background, hardness and alkalinity, water hydrogen indicator value as well as amount of modifier contained in the solid-phase agent have been stated. High degree of water purification in terms of the said ions has been demonstrated.

Characterization of NOM in a drinking water treatment process train with no disinfectant residual

2009 ◽  
Vol 9 (4) ◽  
pp. 379-386 ◽  
Author(s):  
S. A. Baghoth ◽  
M. Dignum ◽  
A. Grefte ◽  
J. Kroesbergen ◽  
G. L. Amy
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Organic Carbon ◽  
Distribution System ◽  
Chemical Properties ◽  
Drinking Water Treatment ◽  
Building Blocks ◽  
Fluorescence Excitation ◽  
Water Treatment Process ◽  
Water Treatment Plants

For drinking water treatment plants that do not use disinfectant residual in the distribution system, it is important to limit availability of easily biodegradable natural organic matter (NOM) fractions which could enhance bacterial regrowth in the distribution system. This can be achieved by optimising the removal of those fractions of interest during treatment; however, this requires a better understanding of the physical and chemical properties of these NOM components. Fluorescence excitation-emission matrix (EEM) and liquid chromatography with online organic carbon detection (LC-OCD) were used to characterize NOM in water samples from one of the two water treatment plants serving Amsterdam, The Netherlands. No disinfectant residual is applied in the distribution system. Fluorescence EEM and LC-OCD were used to track NOM fractions. Whereas fluorescence EEM shows the reduction of humic-like as well as protein-like fluorescence signatures, LC-OCD was able to quantify the changes in dissolved organic carbon (DOC) concentrations of five NOM fractions: humic substances, building blocks (hydrolysates of humics), biopolymers, low molecular weight acids and neutrals.

scholarly journals Electrochemical Surface Biofunctionalization of Titanium through Growth of TiO2 Nanotubes and Deposition of Zn Doped Hydroxyapatite

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Diana Maria Vranceanu ◽  
Elena Ungureanu ◽  
Ionut Cornel Ionescu ◽  
Anca Constantina Parau ◽  
Adrian Emil Kiss ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Pure Titanium ◽  
Chemical Properties ◽  
Secondary Phase ◽  
Xrd Analysis ◽  
Electrochemical Treatment ◽  
Titania Nanotubes ◽  
Nanostructured Surface ◽  
Nanostructured Surfaces ◽  
Zn Content

The current research aim is to biofunctionalize pure titanium (Ti, grade IV) substrate with titania nanotubes and Zn doped hydroxyapatite-based coatings by applying a duplex electrochemical treatment, and to evaluate the influence of Zn content on the physico-chemical properties of hydroxyapatite (HAp). The obtained nanostructured surfaces were covered with HAp-based coatings doped with Zn in different concentrations by electrochemical deposition in pulsed galvanostatic mode. The obtained surfaces were characterized in terms of morphology, elemental and phasic composition, chemical bonds, roughness, and adhesion. The nanostructured surface consisted of titania nanotubes (NT), aligned, vertically oriented, and hollow, with an inner diameter of ~70 nm. X-Ray Diffraction (XRD) analysis showed that the nanostructured surface consists of an anatase phase and some rutile peaks as a secondary phase. The morphology of all coatings consisted of ribbon like-crystals, and by increasing the Zn content the coating became denser due to the decrement of the crystals’ dimensions. The elemental and phase compositions evidenced that HAp was successfully doped with Zn through the pulsed galvanostatic method on the Ti nanostructured surfaces. Fourier Transform Infrared spectroscopy (FTIR) and XRD analysis confirmed the presence of HAp in all coatings, while the adhesion test showed that the addition of a high quantity leads to some delamination. Based on the obtained results, it can be said that the addition of Zn enhances the properties of HAp, and through proper experimental design, the concentration of Zn can be modulated to achieve coatings with tunable features.

scholarly journals Physicochemical characterization of biochars from Eucalyptus maiden Entandrophragma cylindricum (Liboyo), Milicia excelsa (Muvula.) and Ocotea michelsonie (licheche) used in Goma city, DR Congo for water treatment potentials

2021 ◽  
Vol 13 (2) ◽  
pp. 15-24
Author(s):  
Amboko Benjamin Muhiwa ◽  
Mathias Fru Fonteh ◽  
Estella Buleng Tamungang Njoyim ◽  
François N. Gapgue
Keyword(s):  
Water Treatment ◽  
Effective Means ◽  
Physicochemical Characterization ◽  
Chemical Properties ◽  
Cost Effective ◽  
Pollutant Removal ◽  
High Porosity ◽  
Dr Congo ◽  
Weakly Alkaline ◽  
Milicia Excelsa

In recent years, research on biochar as an eco-friendly material and cost-effective means for water treatment, soil amendment and carbon sequestration has gained more attention due to the availability of feedstock, the simplicity of the preparation methods, and their enhanced physico-chemical properties. Given that pyrolysis temperature and resident time amongst other factors have significant effect on biochar’s pollutant removal efficacy, this study focused on the evaluation of some properties of biochars produced by pyrolysis (500 - 600 °C) from Entandrophragma cylindricum (ECB), Eucalyptus maiden (EMB), Milicia excelsa (MEB) and Ocotea michelsonie (OMB) sawdusts for their water treatment potentials by using standardized methods. Biomass generated from wood mill in the city of Goma (DR Congo) is valorised for the first time as potential water  purifier. The highest yield was obtained from OMB (36.6%) which was found to be significantly greater that those of ECB and EMB (p<0.05). All the biochars had neutral to weakly alkaline pH (7.10-7.90), very high porosity (92-94%, with EMB having the highest value) and ash content between 9.40 and 18.40%, with the highest value attributed to OMB). Most physical and chemical characteristics of biochars varied significantly due to different wood species. Potential toxic elements were far belowenvironmental threshold values and exchangeable cations were equally detected in the biochars. The obtained biochars are therefore seen as good media for water treatment.

scholarly journals Instrumentation of the combined processes in water treatment technology

2020 ◽  
Vol 16 (5) ◽  
pp. 55-62
Author(s):  
V. V. Borodychev ◽  
A. E. Novikov ◽  
M. I. Lamskova ◽  
M. I. Filimonov
Keyword(s):  
Water Treatment ◽  
Organic Compounds ◽  
Water Purification ◽  
Irrigation Water ◽  
Plant Cover ◽  
Oil Products ◽  
Morphological Properties ◽  
Combined Processes ◽  
Drain Pipe ◽  
Standard Design

An increase in the volume of industrial effluents, ship accidents, oil breakthroughs at drilling rigs lead to a deterioration in the quality indicators of water in open water sources, including in terms of the content of organic compounds and oil products. The water used for irrigation of agricultural crops, according to most indicators, must meet the water quality requirements for household and drinking purposes. Thus, the total content of oil products in the irrigation water should not exceed 0.1 mg / l. The use of water with the MPC excess leads to significant changes in the morphological properties of the soil, reduces the biological productivity and phytomass of the plant cover. Therefore, the issue of improving machines and devices used in water treatment technologies to increase their reliability and efficiency is one of the topical areas of the research. The aim of the study is to develop a hydrocyclone complex cleaning apparatus, which implements combined processes of capturing both coarse and finely dispersed impurities. Unlike the standard design, the hydrocyclone is supplemented with a filter element installed on the drain pipe, which provides additional water purification from fine mechanical impurities, and a sorption filter designed to remove oil products and other floating organic compounds from water. The proposed hydrocyclone unit provides a comprehensive purification of irrigation water from various types of impurities, due to the combined processes of centrifugal separation and sorption filtration. It eliminates the multistage process of water purification, and regeneration of the sorption filter by the action of centrifugal forces or pressure does not require the use of special regenerating solutions, which increases the manufacturability and environmental friendliness of the water treatment process.

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