scholarly journals Selected elements cations exchange in acidic medium on sorbents surface based on modified brown coal

2017 ◽  
Vol 33 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Agata Stempkowska ◽  
Piotr Izak ◽  
Joanna Mastalska-Popławska
Keyword(s):  
Hydrochloric Acid ◽  
Chemical Modification ◽  
Brown Coal ◽  
Elevated Temperatures ◽  
Exchange Capacity ◽  
Distilled Water ◽  
Desorption Process ◽  
Second Stage ◽  
Before And After ◽  
Static Conditions

Abstract Studies on the sorption and desorption of selected Na+, Ca2+, Mg2+, Mn2+, Cu2+ and Cr3+ cations by materials based on modified brown coal were carried out. The chemical modification of the sorbent material consisted of grinding involving different inorganic substances and organic polymers. Samples were subjected to chemical modification at elevated temperatures for several hours. For comparative purposes, as apart from brown coal, pure humic acids are known for the highest cations exchange capacity, samples of brown coal before and after purification were also analyzed. The ion capacity was determined under static conditions, measuring the difference in the concentration of cations in the sorbent before and after sorption and then after rinsing the sorbent with distilled water (A), and after the desorption process with hydrochloric acid (B). Studies have shown that sorbents based on modified brown coal have rather significant exchange capacities in the range of 270-450 meq/100 g for the first stage and 90-200 meq/100 g for the second stage. It was also found that purified humic acid (450-200 meq/100 g) has the highest exchange capacity and modified brown coal obtained at 250°C has the lowest. The measurement of desorption showed that approximately 10% of the cations are already leached by distilled water and the residue is desorbed under the influence of 10% hydrochloric acid, but the total amount of cations is compatible with the measurement process of the second stage. The sorption affinity to various cations is different. In the case of the sorption measurements, modified sorbents show the highest sorption affinity with respect to calcium, while the unmodified raw brown coal with respect to chromium. The next stage of the measurement showed that the valence of the cation has the highest impact on the sorption affinity.

scholarly journals Eco-Friendly Fired Brick Produced from Industrial Ash and Natural Clay: A Study of Waste Reuse

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 877 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Ahmet Bilgil ◽  
Magdalena Szechyńska-Hebda ◽  
Sławomir Parzych ◽  
Marek Hebda
Keyword(s):  
Compressive Strength ◽  
Bottom Ash ◽  
Unit Weight ◽  
Waste Reuse ◽  
Industrial Solid Waste ◽  
Second Stage ◽  
Before And After ◽  
Fired Bricks ◽  
Two Stages ◽  
And Storage

Bottom ash (BA) is an industrial solid waste formed by the burning of coal. The environmental problems and storage costs caused by this waste increase with every passing day. In this study, the use of BA as an additive (clay substitute) in fired brick production was investigated. The study consisted of two stages. In the first stage, cylinder blocks were produced from clay used in brick production. The second stage was the examination of the experimental substitution of clay with 10, 20, 30 and 40% BA. Samples were fired at 900, 1000, 1100 and 1150 °C to produce fired brick samples. The unit weight, compressive strength (before and after freeze–thawing) and water absorption were analyzed for the samples. The unit weight values decreased in the samples containing BA. The mechanical properties met the conditions prescribed in the relevant standards; i.e., all of the samples fired at 1100 and 1150 °C had a sufficient compressive strength over 20 MPa. The high potential of fired bricks for the construction industry was proved. BA can be used as a clay substitute, while the developed protocol can be used to effectively produce fired bricks.

scholarly journals The Effect of Acetic Acid Treatments on the Quality of Stored Carrot (Daucus carota L.) Seeds

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1176
Author(s):  
Hanna Dorna ◽  
Agnieszka Rosińska ◽  
Dorota Szopińska
Keyword(s):  
Acetic Acid ◽  
Distilled Water ◽  
Storage Duration ◽  
Seed Vigour ◽  
Daucus Carota L ◽  
Two Samples ◽  
Before And After ◽  
Alternaria Dauci ◽  
Acid Treatments

Alternaria dauci (J.G. Kühn) J.W. Groves et Skolko and A. radicina Meier, Drechsler et E.D. Eddy are important seed-transmitted pathogens of carrot. The aim of this study was to evaluate the effects of acetic acid treatments on the quality of stored carrot seeds. Seeds of two samples were soaked for 30 min in 0.5, 1 and 2% acetic acid. Controls included untreated seeds, seeds soaked in distilled water and seeds treated with fungicide Zaprawa Nasienna T 75 WS/DS (a.i. thiram 75%). Germination, vigour and health of untreated and treated seeds were evaluated before and after 5 and 12 months of storage at 4 and 20 °C. Seeds of both samples treated with 0.5 and 1% acetic acid were characterized by higher germination capacity after storage than untreated seeds. However, treatments with 1 and 2% acetic acid negatively affected seed vigour. Generally, seeds of both samples treated with acetic acid were characterized by lower infestation with A. alternata and A. radicina after storage than untreated seeds and seeds soaked in distilled water. Moreover, acetic acid often controlled these fungi more effectively than the fungicide. Regardless of the storage duration, infestation with fungi was higher if seeds of both samples were stored at a lower temperature.

scholarly journals Physicochemical and structural characteristics of HEU-type zeolitic tuff treated by hydrochloric acid

2004 ◽  
Vol 69 (4) ◽  
pp. 273-282 ◽  
Author(s):  
Ana Radosavljevic-Mihajlovic ◽  
Vera Dondur ◽  
Aleksandra Dakovic ◽  
Jovan Lemic ◽  
Magdalena Tomasevic-Canovic
Keyword(s):  
Crystal Structure ◽  
Hydrochloric Acid ◽  
Bosnia And Herzegovina ◽  
Acid Treatment ◽  
Structural Characteristics ◽  
Chemical Analyses ◽  
Zeolitic Tuff ◽  
Zeolitic Tuffs ◽  
Before And After

Samples of natural HEU-type zeolites ? clinoptilolite-Ca, from the Novakovici deposit (near Prijedor, Bosnia and Herzegovina) were treated with the hydrochloric acid of various concentrations (from 10-3Mto 2M). Zeolitic tuffs before and after the acid treatment were examined using IR, XRPD, and chemical analyses. The changes in the crystal structure of acid treated samples showed a significant reduction in the crystallinity of zeolitic tuffs (60?70 %), which were effected by hydrochloric acid with concentrations of 1 M and above.

Microstructure and Mechanical Properties of Ti-6Al-4V Manufactured by SLM

2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Behavior ◽  
Ductile Fracture ◽  
Elevated Temperatures ◽  
Initial Material ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

Taste by Touch: Some Experiments with Octopus

1963 ◽  
Vol 40 (1) ◽  
pp. 187-193
Author(s):  
M. J. WELLS
Keyword(s):  
Hydrochloric Acid ◽  
Fresh Water ◽  
Sea Water ◽  
Olfactory Organ ◽  
Distilled Water ◽  
Quinine Sulphate ◽  
Human Tongue ◽  
Half Strength

1. A method of teaching Octopus chemotactile discriminations is described. 2. The animals can be shown to be capable of distinguishing by touch between porous objects soaked in plain sea water and sea water with hydrochloric acid, sucrose or quinine sulphate added. 3. They can detect these substances in concentrations at least 100 times as dilute as the human tongue is capable of detecting them in distilled water. 4. They can be trained to distinguish between equimolar (0.2 mM) solutions of hydrochloric acid, sucrose and quinine. 5. They can also be trained to distinguish between sea water and fresh water or half-strength sea water or sea water with twice the usual quantity of salt. 6. The function of the ‘olfactory organ’ is discussed. 7. Chemotactile learning is discussed in relation to the means by which Octopus finds its way about the territory around its ‘home’

Characteristics of variably saturated granular bentonite after long-term storage at near-field relevant temperatures

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 343-361 ◽  
Author(s):  
M. Valter ◽  
M. Plötze
Keyword(s):  
Physicochemical Properties ◽  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
Elevated Temperatures ◽  
Near Field ◽  
Exchange Capacity ◽  
Hydraulic Permeability ◽  
Cation Composition ◽  
Retention Capacity

AbstractBentonite is a potential material for use in the engineered barrier of radioactive waste repositories because of its low hydraulic permeability, self-sealing capability and retention capacity. It is expected that bentonite would react at the elevated temperatures accompanying the radioactive decay in the nuclear waste. The presented study was started in order to improve understanding of the coupled influence of temperature and (pore) water on the physicochemical and mineralogical properties of bentonite during thermal treatment under near-field relevant conditions. Granular Na-bentonite MX-80 was differently saturated (Sr = 1–0.05) and stored at different temperatures (50–150°C) in a closed system. Upon dismantling after different periods of time (3 to 18 months), mineralogical characteristics, cation exchange capacity and content of leachable cations, as well as physicochemical properties such as surface area and water adsorption were investigated.The results showed a high mineralogical stability. A slight conversion from the sodium to an earth alkali form of the bentonite was observed. However, considerable changes in the physicochemical properties of the bentonite were observed, particularly by treatment above the critical temperature of 120°C. The cation exchange capacity decreased during heating at 150°C by approximately. 10%. The specific surface area dropped by more than 50%. The water uptake capacity under free swelling conditions showed a slight tendency to lower values especially for samples heated for more than 12 months. The water vapour adsorption ability in contrast drops by 25% already within three months at T = 120°C. These changes are mostly related to the variations in the interlayer cation composition and to smectite aggregation processes. The observed alterations are rather subtle. However, temperatures ⩾ 120°C had a remarkable negative influence on different properties of MX-80.

scholarly journals The Effect of Nanostructure Modification on the Silicate Binder on Its Binding Characteristics and Functional Properties

2014 ◽  
Vol 59 (3) ◽  
pp. 1033-1036 ◽  
Author(s):  
I. Izdebska-Szanda ◽  
A. Baliński ◽  
M. Angrecki ◽  
A. Palma
Keyword(s):  
Chemical Modification ◽  
Sodium Silicate ◽  
Functional Properties ◽  
Elevated Temperatures ◽  
Technological Properties ◽  
Ferrous Alloys ◽  
Silicate Binder ◽  
Binding Characteristics ◽  
The Impact

Abstract A method for the chemical modification of silicate binder (hydrated sodium silicate) affecting the distribution of its nanostructure elements was disclosed. The effect of silicate binder modification on the resulting technological properties of moulding sands, determined under standard conditions and at elevated temperatures in the range from 1000C to 9000C, was discussed. Modification of this type is done on inorganic binders in order to reduce their unfavourable functional properties. It is particularly important when moulding sands with the silicate binder are used for casting of low-melting alloys. Therefore special attention was paid to the impact that modification of inorganic binders may have on the knocking out properties of sands prepared with these binders, when they are used in the process of casting non-ferrous alloys.

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