scholarly journals Zeta-potential and flotability of the scheelite mineral in different type of waters, Part 1: Zeta-potential

2009 ◽  
Vol 63 (5) ◽  
pp. 369-376
Author(s):  
Dragan Milanovic ◽  
Zoran Markovic
Keyword(s):  
Zeta Potential ◽  
Tap Water ◽  
Spring Water ◽  
Rain Water ◽  
Proper Choice ◽  
Distilled Water ◽  
Ph Values ◽  
Different Types

The aim of this work is the investigation of zeta-potential of the mineral scheelite from mine 'Rudnik', located in central Serbia. Electrophoresis measurements using zeta-meter were carried out on four different types of water, namely: tap water, distilled water, rain water and spring water. All types of water had different hardness and conductivity as well as natural pH values. It was found that the zeta-potential of mineral scheelite depends on the hardness and electro-conductivity of the chosen type of water as well as on Ca2+ content. The results obtained reveal the importance of proper choice of water as well as the type of reagents for flotation processes.

scholarly journals Zeta-potential and flotability of the scheelite mineral in different type of waters, Part 2: Flotability

2009 ◽  
Vol 63 (5) ◽  
pp. 377-385
Author(s):  
Dragan Milanovic ◽  
Zoran Markovic
Keyword(s):  
Tap Water ◽  
Size Fraction ◽  
Spring Water ◽  
Distilled Water ◽  
Particle Size Fraction ◽  
Proper Selection ◽  
Ph Values ◽  
Different Types ◽  
Tube Cell ◽  
Selection Of

The aim of this work was to study floatability of the mineral sheelite from mine 'Rudnik', central Serbia. Flotation tests of the mineral in a Hallimond tube cell were carried out in four different types of water, namely: tap water, distilled water, rain water and spring water. All types of water had different hardness and conductivity as well as natural pH values. It was found that the flotability of mineral scheelite depends on the hardness and electro-conductivity of the chosen type of water as well as on Ca2+ content. Also, it was found the floatability of mineral depends on the scheelite particle size fraction used in microflotation experiments. Presented results may be useful for proper selection of type of water, as well of the type of reagents used in flotation processes.

scholarly journals Sensory profiles of sweeteners in aqueous solutions

2011 ◽  
Vol 24 (No. 6) ◽  
pp. 283-287 ◽  
Author(s):  
A. Šedivá ◽  
Z. Panovská ◽  
J. Pokorný
Keyword(s):  
Aqueous Solutions ◽  
Bitter Taste ◽  
Sucrose Solution ◽  
Tap Water ◽  
Relative Accuracy ◽  
Distilled Water ◽  
Iso Standards ◽  
Metallic Taste ◽  
Different Types ◽  
Sensory Profiles

Sensory profiles of saccharin, acesulfame K, aspartame, and neotame were compared with that of sucrose in three different types of water (tap water, commerical Crystalis water, and distilled water) under the conditions of the respective ISO standards. The intensities of off-flavours, especially bitter and metallic tastes, were higher in the solutions of synthetic sweeteners than in that of sucrose. The aspartame solution was the sample closest to the sucrose solution, and the intensity of off-flavours was significantly higher in acesulfame solution. Ratings of the bitter taste were related to those of the metallic taste, the relation being semilogarithmic. The performancies of different assessors were nearly the same in all ratings, and the absolute values of the ratings of sweetness and different off-flavours had the same repeatabilities. The relative accuracy was, naturally, much higher in off-flavours than in the case of sweetness.  

scholarly journals ANALYSIS OF THE EFFICIENCY OF USING THE CULINARY PROCESSING OF MUSHROOMS IN ORDER TO REDUCE THE CONCENTRATION OF HEAVY METALS IN THEM

2020 ◽  
pp. 209-222
Author(s):  
Oksana Vradiy
Keyword(s):  
Heavy Metals ◽  
Tap Water ◽  
Absorption Spectrometry ◽  
Forest Steppe ◽  
Distilled Water ◽  
Lead And Cadmium ◽  
Different Types ◽  
The Village ◽  
The Town ◽  
Copper Lead

The samples of mushrooms were collected in the forestry of the village Tyvriv and the town of Kalynivka, Vinnytsia and Kalynivka districts, in the conditions of Right-Bank Forest-Steppe of Ukraine. The studies of heavy metals concentration were performed in the scientific agrochemical laboratory of the Department of Ecology and Environmental Protection, the Faculty of Agronomy and Forestry at Vinnytsia National Agrarian University. The concentrations of Cu, Zn, Pb and Cd of the studied mushrooms were determined by the method of atomic absorption spectrometry after the dry mineralization. The research of the effect of culinary processing on the concentration of heavy metals in mushrooms were conducted according to the following scheme: 1. The control: mushrooms, cleaned and washed with tap water; 2. Option 1: mushrooms soaked in tap water for 3 hours and boiled in it; 3. Option 2: mushrooms soaked in the water without mineral residue for 3 hours and boiled in it; 4. Option 3: mushrooms soaked in distilled water for 3 hours and boiled in it. Summarizing the obtained results, it should be noted that the most effective way to reduce the concentration of lead and cadmium in mushrooms was the option of soaking and boiling mushrooms in the water without mineral residue. The most effective way to reduce the concentration of zinc and copper was Option 3, where distilled water was used. The influence of soaking and boiling mushrooms in different types of water is investigated. When soaking and boiling mushrooms in tap water for 3 hours, the concentration of zinc in them was found to decrease from 1.01 to 1.04 times, the concentration of copper – from 1.0 to 1.2 times, the concentration of lead – from 1.09 to 1.16 times and the concentration of cadmium – from 1.08 to 1.2 times. When soaking and boiling mushrooms in the water without mineral residue, the concentration of zinc decreased from 1.01 to 1.04 times, the concentration of copper – from 1.16 to 1.25 times, the concentration of lead – from 1.8 to 2.0 times and the concentration of cadmium – from 1.75 to 2.0 times. When soaking mushrooms and boiling them in distilled water, the concentration of zinc decreased from 1.13 to 1.18 times, the concentration of copper – from 1.2 to 1.29 times, the concentration of lead – from 1.22 to 1.28 times and the concentration of cadmium – from 1.08 to 1.2 times. Key words: mushrooms, concentration, zinc, copper, lead, cadmium, distilled water, water without mineral residue, tap water, boiling of mushrooms.

The pH tolerance of Daphnia pulex (Leydig, emend., Richard)

1969 ◽  
Vol 47 (6) ◽  
pp. 1173-1175 ◽  
Author(s):  
P. Davis ◽  
G. W. Ozburn
Keyword(s):  
River Water ◽  
Tap Water ◽  
Daphnia Pulex ◽  
Distilled Water ◽  
Ph Values ◽  
Ph Tolerance ◽  
Dilute Sodium Hydroxide ◽  
Aquarium Water ◽  
Ph Range ◽  
Sulfuric Acid Solutions

The survival time and reproduction of female Daphnia pulex in solutions varying in pH have been observed. Dilute sodium hydroxide or sulfuric acid solutions were added to four different diluent waters: distilled water, aerated tap water, aerated and filtered tap water from an aquarium containing dace minnows, and McIntyre River water. D. pulex (initially up to 72 hours old) survived for the duration of the experiment (32 hours) in river water within a pH range of 6.1–10.3; in aquarium water within a pH range of 4.3–10.4; only at pH 6.4 and pH 7.6 in distilled water; and in none of the solutions using aerated tap water. The dissolved oxygen content was measured at the beginning and end of every experiment and was found never to fall below 6.2 p.p.m. Those individuals which survived were cultured in the laboratory and parthenogenesis was observed at pH values between 7.0 and 8.7.

scholarly journals Microbiological and physico-chemical properties of packaged, residential treatment device and tap water drinking water and their possible effects on human health

2018 ◽  
Vol 8 (4) ◽  
pp. 767-776
Author(s):  
Neriman Aydın ◽  
Mustafa Tanrıverdi ◽  
Birgül Özçırpıcı ◽  
Coşkun Cüce ◽  
Fulya Alben ◽  
...  
Keyword(s):  
Drinking Water ◽  
Residential Treatment ◽  
Treatment Process ◽  
Tap Water ◽  
Chemical Properties ◽  
Cross Sectional ◽  
Ph Values ◽  
Physico Chemical ◽  
Different Types ◽  
Purification Of Water

Abstract The objective of this study was to examine the microbiological and physico-chemical properties of different types of drinking water used. The cross-sectional type study was carried out between January 1 and April 30, 2016. The samples acquired for the study from 50 packages, 50 tap water taps, and 50 residential treatment devices were examined both microbiologically and biochemically. The pH values varied between 5.57 and 8.26. pH values of tap and packaged waters were all determined to be proper, and improperly low pH values were determined in 25 of the samples acquired from the residential treatment devices. It was determined that amounts of fluoride, chloride, nitrate, nitrite, arsenic, and ammonium were all acceptable. Fluoride amounts were determined to be high at a statistically significant level in packaged and residential treatment device water (p = 0.000). Escherichia coli was determined in 10% of tap water and 2% of packaged water. Microbiological contaminations of the samples collected after the pump-faucet and water fountain were determined to be greater in comparison with those of samples collected directly from packaged waters. It was determined that the residential treatment process is applied more on drinkable waters. The purification of water causes significant physico-chemical changes.

scholarly journals Microhardness of the enamel exposed to whitening dentifrices.

2017 ◽  
Vol 24 (2) ◽  
pp. 90
Author(s):  
Alex Mendez De Arruda ◽  
André Luiz Fraga Briso ◽  
Osmir Batista De Oliveira Júnior ◽  
Paulo Henrique Dos Santos ◽  
Simone Cristina Tosti
Keyword(s):  
Hydrogen Peroxide ◽  
Static Load ◽  
Tap Water ◽  
Artificial Saliva ◽  
Distilled Water ◽  
Carbamide Peroxide ◽  
Different Types ◽  
Bovine Enamel ◽  
Weight Proportion

Introduction: The purpose of this study is to verify the effect of three different types of dentifrices on the superficial microhardness of bovine enamel. Methods: Forty-eight 4x4mm dental fragments were polished and randomly divided into 4 groups: GI, conventional silica-based dentifrice; GII, hydrogen peroxide-based dentifrice; GIII, carbamide peroxide-based dentifrice; and GIV, immersion in artificial saliva. After polished, the specimens received five indentations of 25g static load, for 5 seconds. Subsequently, specimens from groups GI, GII and GIII were immersed in solution containing dentifrice and distilled water, in weight proportion of 1:2, for 15 minutes daily. After this period, fragments were rinsed in tap water and stored in artificial saliva at 37oC. This procedure was repeated for 21 days and then a new analysis of the microhardness was performed. Results and conclusion: The results were submitted to ANOVA and Fisher’s test at 5%. It was concluded that all samples treated with dentifrices showed hardness decrease, being most pronounced in dentifrices containing peroxide.

scholarly journals Comparative Study of Portland Cement-based and Zeolite-based Concretes in Terms of Hexavalent Chromium Leaching

2016 ◽  
Vol 62 (4) ◽  
pp. 1-4
Author(s):  
Jozef Oravec ◽  
Adriana Estokova
Keyword(s):  
Comparative Study ◽  
Portland Cement ◽  
Hexavalent Chromium ◽  
Water Soluble ◽  
Rain Water ◽  
Distilled Water ◽  
Ph Values ◽  
Water Media

Abstract The paper presents the results of the leaching study of Portland cement-based and zeolite-based concretes regarding water soluble hexavalent chromium. Three leaching water media (distilled water, rain water, and Britton-Robinson buffer) of various pH values were under investigation. The correlation between pH and leached-out concentrations of chromium was not confirmed. The content of hexavalent water-soluble chromium in leachates of zeolite-based concretes was found to be higher than that in leachates of Portland cement-based samples.

scholarly journals Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

2018 ◽  
Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Analysis ◽  
Multiple Comparisons ◽  
The Other ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Friedman Test ◽  
Time Intervals ◽  
Ph Values ◽  
Evaluation Time

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.

Adsorption of Organic Compounds on Refined Latvian Clay

2018 ◽  
Vol 788 ◽  
pp. 83-88
Author(s):  
Oskars Leščinskis ◽  
Ruta Švinka ◽  
Visvaldis Švinka
Keyword(s):  
Methyl Orange ◽  
Zeta Potential ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Organic Compounds ◽  
Clay Mineral ◽  
Rhodamine B ◽  
Ph Value ◽  
Ftir Spectra ◽  
Ph Values

Clays are materials consisting of clay minerals and non-clay minerals. Clay mineral fraction is considered to be a nanofraction. Clay minerals can be used for water purification and treatment. Description and characterization of 3 different Latvian clay nanosized minerals from 3 different geological periods (clay Liepa from Devonian period, clay Vadakste from Triassic period and clay Apriki from Quaternary period) as well as their adsorption capacity concerning organic compounds such as methyl orange and rhodamine B are summarized. Nanosized clay mineral particles were obtained using sedimentation method. Particle size distribution, zeta potential and FTIR spectra is given. The adsorption tests of above mentioned organic compounds were carried out in water solutions at 3 different pH values. The adsorption values were determined by means of UV-spectrophotometric technique. Zeta potential values for clay minerals Apriki, Liepa and Vadakste are -40.9 mV, -49.6 mV and -43.0 mV, respectively. FTIR spectra show similar tendencies for all 3 clay minerals. The best adsorption capacity concerning methyl orange and rhodamine B were in solutions with a pH value of 2, whereas at neutral and alkaline pH values adsorption in 24 hours was not observed.

scholarly journals Extraction of 137Cs from cetraria islandica lichen with water

2006 ◽  
Vol 71 (5) ◽  
pp. 565-571 ◽  
Author(s):  
Ana Cuculovic ◽  
Dragan Veselinovic ◽  
Scepan Miljanic
Keyword(s):  
Distilled Water ◽  
137Cs Content ◽  
Lichen Sample ◽  
Different Types ◽  
Water Volumes

Extraction of 137Cs sorbed in samples of C. islandica using distilled water was investigated. An equation desrcribing the reduction of the 137Cs content in a dry lichen sample by the number of water volumes used for successive extractions was defined. The possibilities of the existence of two different types of 137Cs sorption in the lichen was established.

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