Skocz do pozycji: 1.

Tytuł:

Adsorption of Chromium (VI) on Raw and Modified Carpathian Diatomite

Autorzy:

Puszkarewicz, Alicja
Kaleta, Jadwiga

Powiązania:

https://bibliotekanauki.pl/articles/125262.pdf

Data publikacji:

2019

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

adsorption
diatomite
chromium(VI)
chromium removal

Opis:

The paper presents the research on the usability of natural Carpathian diatomite for removing chromate ions from water solutions. The concentration of chromium (VI) in test water was C₀ = 1 g/m³. Both raw diatomite and the diatomite modified with iron compounds of granulation 0.5–1.0 mm were tested. The process kinetics, as well as the effect of water reaction and the diatomite type on chromium sorption were determined under static conditions (no through flow). For both diatomite types, the chromium adsorption proceeded most effectively at pH 4. The effect of diatomite modification with iron compounds on the effectiveness of chromium (VI) adsorption was determined on the basis of Freundlich adsorption isotherm. Compared to raw diatomite, the modified adsorbent (diatomite-Fe) exhibited great sorption capacity for chromate ions from water. When applied under dynamic conditions (v = 4 m/h), as filtration bed, it removed chromium compounds from water very effectively. It makes diatomite-Fe material a promising candidate for application in water treatment systems. The chromium concentration in the effluent oscillated within C_k = 0.001–0.002 mg/dm³, and the adsorption capacity of the bed, determined in the bed breakthrough point, reached P_p = 316.8 mg/kg.

Źródło:

Journal of Ecological Engineering; 2019, 20, 7; 11-17
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:

Production of Chromium Boride Layers on Carbon Steel with Conversion Treatment: Chromium Deposition + Diffusion Annealing

Autorzy:

Boubaaya, R.
Benarioua, Y.
Allaoui, O.
Djendel, M.

Powiązania:

https://bibliotekanauki.pl/articles/1031720.pdf

Data publikacji:

2017-09

Wydawca:

Polska Akademia Nauk. Instytut Fizyki PAN

Tematy:

carbon steel
boriding
chromium plating
diffusion annealing
chromium boride

Opis:

The present study has been conducted in order to obtaining chromium boride layers on carbon steel using a conversion processing comprising the following steps: boriding treatment in order to increase the amount of boron atoms in the steel surface, deposition of a thin layer of pure chromium using electrolytic method, and finally an annealing treatment for boron diffusion and formation of boride layer until complete transformation of chromium layer. Depending on the method used (chromium deposition followed by boriding or boriding followed by chromium deposition) and the holding time, the partial or complete conversion is obtained as a result of the diffusion process. The role of the annealing temperature on transformation rates of chromium into chromium boride films was investigated. It is shown that for 1 h at 900°C, the chromium layer is totally transformed. The scanning electron microscopy analysis and X-ray diffraction showed the presence of CrB and CrB₂ chromium borides in addition of FeB and Fe₂B iron borides.

Źródło:

Acta Physica Polonica A; 2017, 132, 3; 541-543
0587-4246
1898-794X

Pojawia się w:

Acta Physica Polonica A

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:

Sorption and reduction of chromiumion ions by the chelating ion exchanger Diaion CR20

Autorzy:

Wójcik, Grzegorz

Powiązania:

https://bibliotekanauki.pl/articles/109632.pdf

Data publikacji:

2019

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

chromium(III)
chromium(VI)
reduction
ion exchange
speciation
chelating resin

Opis:

The chelating ion exchanger Diaion CR20 was applied for removal of chromium(VI) ions in the pH range from 1.5 to 10 and in the presence of 1 M H₂SO₄. The speciation analysis was used to predict the reduction process. Reduction of chromium(VI) to chromium (III) was observed during the chromium(VI) ions sorption. The kinetic parameters for the pseudo-first-order and pseudo-second-order, Elovich and intraparticle diffusion models were calculated. The most common three isotherm models: Freundlich, Langmuir and Dubinin-Radushkevich were used to describe chromium(VI) uptake. It was proved that the polyamine groups present in selected ion exchanger are able to sorb both chromium(VI) and (III) ions. The maximal sorption capacity towards chromium(VI) ions was estimated at pH 1.5 – 169.49 mg Cr(VI)/g and 159.31 mg Cr(VI)/g in 1 M H₂SO₄. Both static and column methods were used in the investigations.

Źródło:

Physicochemical Problems of Mineral Processing; 2019, 55, 6; 1382-1393
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Wpływ wybranych modyfikatorów na parametry stereologiczne węglików w żeliwie chromowym
The influence of chosen modifiers on stereological parameters of carbides of chromium cast iron

Autorzy:

Studnicki, A.
Suchoń, J.

Powiązania:

https://bibliotekanauki.pl/articles/381127.pdf

Data publikacji:

2011

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

żeliwo chromowe
węglik chromu
parametry stereologiczne
chromium cast iron
chromium carbide
stereological parameters

Opis:

W artykule przedstawiono wyniki badań stereologii węglików w modyfikowanym żeliwie chromowym odpornym na zużycie ścierne. W składzie modyfikatorów były następujące pierwiastki: bor, niob, wanad, cer i lantan (MZR), azot. W tabelach i na wykresach pokazano wpływ użytych modyfikatorów na takie parametry stereologiczne węglików jak: wielkość, obwód, współczynnik kształtu i udział objętościowy.
The results of investigations of stereological carbides in the modified wear resistance chromium cast iron resistant were introduced in the article. There were following elements: boron, niobium, vanadium, cerium and lanthanum (RE), nitrogen in the composition of modifiers. The influence of used modifiers on such stereological parameters of carbides as: size, perimeter, shape coefficient and volume fraction was showed in tables and on diagrams.

Źródło:

Archives of Foundry Engineering; 2011, 11, 3 spec.; 282-288
1897-3310
2299-2944

Pojawia się w:

Archives of Foundry Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:

The effect of chromium on ruminant health

Autorzy:

Zarczynska, K.
Krzebietke, S.

Powiązania:

https://bibliotekanauki.pl/articles/1192470.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza

Tematy:

chromium
ruminants
essential nutrient
toxicity

Opis:

Chromium (Cr) is a micronutrient that occurs in the natural environment in different oxidation states. Natural compounds contain chromium in the +3 oxidation state, whereas chromic(VI) acid derivatives are industrial products with strong toxicity. Hexavalent chromium compounds can adversely affect the respiratory system and the gastrointestinal tract, cause skin changes, and exert carcinogenic, mutagenic, embryotoxic as well as teratogenic effects. Research indicates that both organic and inorganic trivalent chromium compounds improve carbohydrate, lipid, and protein metabolism. These compounds are found in many enzymes, and they influence antioxidant processes, regulation of immune responses, and the secretion of hormones and selected vitamins in the body. In animals, Cr has been found to increase fat-free body mass, improve reproductive parameters, enhance growth, increase feed conversion efficiency, boost immunity, and decrease mortality. It has been suggested that Cr supplements can intensify the effects of insulin, decrease the plasma levels of non-esterified fatty acids (NEFAs), decrease triglyceride concentrations in the liver, and improve glucose tolerance, thus improving the performance and productivity of cattle in the perinatal period. Symptoms of chromium deficiency, including decreased feed intake, lower weight gains, reproductive disorders, and higher lipid levels, are observed in cattle fed diets that are low in this nutrient, and in animals that are exposed to considerable and prolonged stress. In ruminants, chromium supplementation is recommended during thermal stress, in the perinatal period, and during infections.

Źródło:

Journal of Elementology; 2020, 25, 3; 893-903
1644-2296

Pojawia się w:

Journal of Elementology

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:

Chromium in urothelial carcinoma of the bladder

Autorzy:

Gołąbek, Tomasz
Socha, Katarzyna
Kudelski, Jacek
Darewicz, Barbara
Markiewicz-Zukowska, Renata
Chłosta, Piotr
Borawska, Maria

Powiązania:

https://bibliotekanauki.pl/articles/987066.pdf

Data publikacji:

2017

Wydawca:

Instytut Medycyny Wsi

Tematy:

chromium
bladder cancer
heavy metals

Opis:

Introduction and objectives. Many epidemiological and experimental studies report a strong role of chemical carcinogens in the etiology of bladder cancer. However, the involvement of heavy metals in tumourigenesis of urothelial carcinoma of the bladder has been poorly investigated. Therefore, the aim of this study was to examine the relationship between chromium (Cr) and bladder cancer. Materials and methods. Chromium concentration in two 36-sample series of bladder cancer tissue and sera from patients with this neoplasm were matched with those of a control group. The amount of trace elements in every tissue sample was determined using atomic absorption spectrometry. This was correlated with tumour stage. Results. While the median chromium concentration levels reached statistically higher values in the bladder cancer tissue, compared with the non-cancer tissue (99.632ng/g and 33.144ng/g, respectively; p<0.001), the median Cr levels in the sera of the patients with this carcinoma showed no statistical difference when compared to those of the control group (0.511μg/l and 0.710μg/l, respectively; p=0.408). The median levels of Cr in the bladder tissue, depending on the stage of the tumour, compared with the tissue without the neoplasm, observed the same relationship for both non-muscle invasive and muscleinvasive tumours (p<0.001 and p<0.01, respectively). Conclusions. This study shows that patients with urothelial carcinoma of the bladder had higher tissue Cr levels than people without tumour, while no difference was found in the Cr serum levels between the two groups of patients under investigation.

Źródło:

Annals of Agricultural and Environmental Medicine; 2017, 24, 4
1232-1966

Pojawia się w:

Annals of Agricultural and Environmental Medicine

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:

Removal of chromium and strontium from aqueous solutions by adsorption on laterite

Autorzy:

He, Yong
Chen, Yong-Gui
Zhang, Ke-Neng
Ye, Wei-Min
Wu, Dong-Yu

Powiązania:

https://bibliotekanauki.pl/articles/204768.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

adsorption
isotherms
chromium
strontium
laterite

Opis:

To investigate the adsorptive properties of a local laterite deposited in Chenzhou, Hunan province, China, the adsorptive properties of the natural laterite were investigated by batch technique in this study. The effects of contact time, pH, ionic strength, temperature, and the concentration on adsorption properties were also analyzed. The obtained experimental results show that the main mineral composition of laterite is kaolinite and montmorillonite. The adsorption process achieved equilibrium within 60 minutes and 90 minutes for Sr(II) and Cr(VI), respectively. The adsorption capacities for Cr(VI) and Sr(II) by the laterite were about 7.25 mg·g^-1 and 8.35 mg·g^-1 under the given experimental conditions, respectively. The equilibrium adsorption data were fitted to the second-order kinetic equation. The adsorption capacity for Sr(II) onto the laterite increased with increasing pH from 3–11 but decreased with increasing ionic strength from 0.001 to 1.0 M NaCl. The Sr(II) adsorption reaction on laterite was endothermic and the process of adsorption was favored at high temperature. Similarly, the adsorption capacity for Cr(VI) onto the laterite increased with increasing pH from 3–11, however, the ionic strength and temperature had an insignificant effect on Cr(VI) adsorption. The adsorption of Cr(VI) and Sr(II) was dominated by ion exchange and surface complexation in this work. Furthermore, the Langmuir and Freundlich adsorption isotherm model was used for the description of the adsorption process. The results suggest that the studied laterite samples can be effectively used for the treatment of contaminated wastewaters.

Źródło:

Archives of Environmental Protection; 2019, 45, 3; 11-20
2083-4772
2083-4810

Pojawia się w:

Archives of Environmental Protection

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:

Effect of Reactive Materials on the Content of Selected Elements in Indian Mustard Grown In Cr(VI)-Contaminated Soils

Autorzy:

Radziemska, M.
Mazur, Z.
Fronczyk, J.
Jeznach, J.

Powiązania:

https://bibliotekanauki.pl/articles/123845.pdf

Data publikacji:

2016

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

chromium
Indian mustard
macroelements
soil

Opis:

Reactive materials represent a promising agent for environmental co-remediation. The research was aimed to determine the influence of hexavalent chromium in doses of 0, 25, 50, and 150 mg Cr(VI).kg^-1 of soil as well as zero valent-iron, and lignite additives on the content of macroelements in the Indian mustard (Brassica juncea L.). The average accumulation of the analysed elements in Indian mustard grown in Cr(VI) contaminated soil were found to follow the decreasing order Mg>Na>P>Ca>K. Soil contamination at 150 mg Cr(VI).kg^-1 of soil led to the highest increase in magnesium, calcium, sodium, and potassium content in Indian mustard. The application of zero-valent iron had a positive influence on the average Na and K content of the tested plant. The application of lignite had a positive influence on the average magnesium, sodium and calcium content in the above-ground parts of the studied plant. In the non-amended treatments (without reactive materials), the increasing rates of chromium (VI) had an explicitly positive effect on the content of phosphorous and sodium in Indian mustard.

Źródło:

Journal of Ecological Engineering; 2016, 17, 2; 141-147
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:

Chrom i jego związki – metoda oznaczania
Chromium end its compounds – determination method

Autorzy:

Surgiewicz, J.

Powiązania:

https://bibliotekanauki.pl/articles/138341.pdf

Data publikacji:

2009

Wydawca:

Centralny Instytut Ochrony Pracy

Tematy:

chrom
związki chromu
metoda analityczna
narażenie zawodowe
chromium
chromium compounds
analytical method
occupational exposure

Opis:

Metodę stosuje się do ilościowego oznaczania chromu metalicznego (CAS 7740-47-3) i związków chromu (II) i chromu (III) występujących w powietrzu na stanowiskach pracy podczas kontroli warunków sanitarnohigienicznych. Metoda polega na pobraniu chromu, związków chromu (II) i chromu (III) na filtr nitrocelulozowy, mineralizacji filtra za pomocą stężonego kwasu azotowego, sporządzeniu roztworu do analizy i oznaczeniu chromu w sporządzonej do analizy próbce z wykorzystaniem metody absorpcyjnej spektrometrii atomowej z atomizacją próbki w płomieniu podtlenek azotu-acetylen. Metoda została całkowicie zwalidowana dla związków chromu (III). Oznaczalność metody wynosi 0,035 mg/m3.
The method is based on stopping selected chromium and its compounds chromium (II) and chromium (III) on a membrane filter, mineralizing the sample with concentration nitric acid and preparating the solution for analysis in diluted nitric acid. Chromium and its compounds in the solution are determined as chromium with flame atomic absorption spectrometry. The detection limit of determined chromium and its compounds for this method is 0.035 mg/m3.

Źródło:

Podstawy i Metody Oceny Środowiska Pracy; 2009, 1 (59); 113-118
1231-868X

Pojawia się w:

Podstawy i Metody Oceny Środowiska Pracy

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:

Formation of Cr ohmic contact on graphitized 6H-SiC(0001) surface

Autorzy:

Grodzicki, M
Mazur, P
Wasielewski, R
Ciszewski, A

Powiązania:

https://bibliotekanauki.pl/articles/173424.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

silicon carbide
chromium
electric contacts
graphitization

Opis:

Ohmic electrical contacts were formed at room temperature on n-type, Si-oriented 6H-SiC substrates, with Cr layers vapor-deposited under ultra-high vacuum conditions on the samples being graphitized prior to the deposition. The contacts reveal a very good linearity of the local I–V characteristics. This method of ohmic contact formation does not require the use of samples with high doping concentration and the application of high-temperature annealing during the processing of contacts. Results of characterization of the contacts and of the in situ graphitization process of the SiC substrates, obtained by X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and atomic force microscopy (AFM) with conducting tip, are given in this paper.

Źródło:

Optica Applicata; 2013, 43, 1; 91-98
0078-5466
1899-7015

Pojawia się w:

Optica Applicata

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

The kinetic reduction of Cr(VI) by yeast Saccharomyces cerevisiae, Phaffia rhodozyma and their protoplasts

Autorzy:

Chwastowski, Jarosław
Kołoczek, Henryk

Powiązania:

https://bibliotekanauki.pl/articles/1039500.pdf

Data publikacji:

2013

Wydawca:

Polskie Towarzystwo Biochemiczne

Tematy:

chromium
Phaffia rhodozyma
pollution
Saccharomyces cerevisiae

Opis:

Chromium in the sixth oxidation state may easily penetrate cellular membranes via non-specific sulfate transporters due to its tetrahedral symmetry (high similarity to SO42- and HPO42-). This feature makes chromium a toxic and hazardous pollutant responsible for the deterioration of midland water quality. The aim of the study was to evaluate the capacity of two yeast species - Saccharomyces cerevisiae and Phaffia rhodozyma - and their protoplasts to reduce Cr(VI) to lower oxidation states. The study also deals with the behavior of the yeasts upon the presence of elevated sulfate ions as a competitive inhibitor of chromate transport by the sulfate transporters. The chromate-reducing activities were monitored by determination of Cr(V) free radical form with the use of L-band (1.2 GHz) EPR (electron paramagnetic resonance) spectroscopy. It was observed that both of the studied yeast strains exhibited the ability to reduce Cr(VI) applied at 4 mM. The cells of P. rhodozyma showed about 3.5 times higher reduction than S. cerevisiae. The reduction efficiency was significantly improved when the protoplasts of both strains were used and reached 100% in the first 10 minutes of the reduction process which suggests that the cellular wall may have a notable influence on the uptake and/or inhibition of chromium reduction process. The reduction effect of P. rhodozyma cells and protoplasts may be associated with the more sufficient production of metabolites (such as glutathione and cysteine), which may also be responsible for the increased tolerance of the strain towards high concentrations of toxic chromium.

Źródło:

Acta Biochimica Polonica; 2013, 60, 4; 829-834
0001-527X

Pojawia się w:

Acta Biochimica Polonica

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:

Reduction of chromium(VI) ions from aqueous solutions by using the solvent impregnated resin

Autorzy:

Wójcik, G.
Hubicki, Z.

Powiązania:

https://bibliotekanauki.pl/articles/115625.pdf

Data publikacji:

2011

Wydawca:

Fundacja na Rzecz Młodych Naukowców

Tematy:

sorption of chromium(VI) ions
reduction

Opis:

The solvent impregnated resins enables effective recovery of microquantities of chromium(VI) ions from wastewaters. The solvent impregnated resin (SIR) Amberlite XAD 7 HP as polymer matrix has been prepared by the wet-impregnation technique. Aliquat 336 was employed as the extractant and acetone as the solvents for impregnation. Sorption of chromium(VI) was investigated in the batch process . Sorption of chromium(VI) was studied in the pH range from 1.5 to 7. It was stated that sorption of chromium(VI) ions depends on acidity of solution. The values of recovery factors of chromium(VI) are higher at low pH than in neutral solution. The speciation of chromium was investigated in the studied pH range. Reduction of chromium(VI) to chromium(III) under acidic conditions was observed. Chromium was determined by using the spectrophotometric and atomic absorption spectroscopy methods. Both methods permit to observe changing of valence of chromium(III) and (VI) oxidation states. The prepared SIR is a new sorbent used for recovery of chromium ions from wastewaters.

Źródło:

Challenges of Modern Technology; 2011, 2, 3; 41-43
2082-2863
2353-4419

Pojawia się w:

Challenges of Modern Technology

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:

Quick and simple speciation analysis of chromium in cements

Autorzy:

Grabarczyk, Malgorzata
Wardak, Cecylia

Powiązania:

https://bibliotekanauki.pl/articles/2146952.pdf

Data publikacji:

2022

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

cement
extraction
chromium speciation
voltammetric determination

Opis:

The extraction of total Cr(VI) from commercially available cements, based on DTPA + 0.2 mol dm-3 (NH4)2SO4/NH4OH mixture solution and subsequent selective determination of Cr(VI) has been proposed. The determination was carried out using the adsorptive voltammetric stripping method. The study was conducted using three different commercially available cement samples. It has been checked that the proposed extraction procedure guaranteed no changes of chromium speciation during cement analysis. For comparison extraction was also carried out with the use of recommended by United States Environmental Protection Agency (EPA) Method 3060A, based on 0.28 mol dm-3 Na2CO3 + 0.5 mol dm-3 NaOH). Additionally, the extraction process was carried out using only distilled water as an extraction mixture which allows to evaluate concentration of only soluble Cr(VI) forms contained in cement. In all three cements, the content of soluble Cr(VI) was below 2 ppm, i.e. the limit value by European Union Directive 2003/53/EC.

Źródło:

Physicochemical Problems of Mineral Processing; 2022, 58, 2; art. no. 144445
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:

High Structural Stability and Adsorption Capacity of Zn/Al-Biochar and Cu/Al-Biochar Toward Adsorption of Cr(VI)

Autorzy:

Palapa, Neza Rahayu
Taher, Tarmizi
Siregar, Patimah Mega Syah Bahar Nur
Normah, -
Juleanti, Novie
Wijaya, Alfan
Badri, Arini Fousty
Lesbani, Aldes

Powiązania:

https://bibliotekanauki.pl/articles/1839586.pdf

Data publikacji:

2021

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

layered double hydroxide
chromium
adsorption
reusability

Opis:

Layered double hydroxide (LDH) Zn/Al and Cu/Al was synthesized by using the coprecipitation method under base condition at pH 10 following with formation of composites based on biochar (BC) to form Zn/Al-BC and Cu/ Al-BC. The materials were characterized by XRD, FTIR, BET, and thermal analyses. Furthermore, materials was applied as adsorbent of Cr(VI) on aqueous solution. The performance of composites as adsorbent was evaluated by reusability of adsorbent toward Cr(VI) adsorption process. The results showed that Cu/Al-BC and Zn/Al-BC can reuse the re-adsorption process with the adsorption ability of more than 60%. The adsorption capacity of Cu/ Al-BC and Zn/Al-BC was higher than that of starting materials and up to 384.615 mg/g for Cu/Al-BC and 666.667 mg/g for Zn/Al-BC. Both composites showed the potential adsorbents to remove Cr(VI) from aqueous solution.

Źródło:

Journal of Ecological Engineering; 2021, 22, 4; 213-223
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:

Effect of Chromium Picolinate and Chromium Nanoparticles Added to Low- or High-Fat Diets on Chromium Biodistribution and the Blood Level of Selected Minerals in Rats

Autorzy:

Stępniowska, Anna
Juśkiewicz, Jerzy
Tutaj, Krzysztof
Fotschki, Joanna
Fotschki, Bartosz
Ognik, Katarzyna

Powiązania:

https://bibliotekanauki.pl/articles/2159288.pdf

Data publikacji:

2022-09-05

Wydawca:

Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie

Tematy:

minerals
chromium
nanoparticles
high-fat diet

Opis:

The metabolism of chromium (Cr), calcium (Ca), phosphorus (P), iron (Fe), copper (Cu), and zinc (Zn) is interconnected, and their deficiency or excessive accumulation may lead to various disturbances, including anemia and diabetes. The current research was undertaken to determine whether low-fat or high-fat diets with the Cr(III) addition in the form of picolinate (CrPic) or nanoparticles (CrNPs) have an interactive effect on the retention and accumulation of this element in organs and the content of P, Ca, Fe, Cu and Zn in the blood plasma of rats. The experiment was performed using 48 outbred male Wistar rats fed a low-fat or high-fat semi-purified rat diet with dietary addition of chromium at a dose of 0.3 mg/kg body weight. The obtained results point to the paramount importance of the dietary Cr form on the excretion pattern of this microelement. It has been found that CrNPs were to a greater extent excreted from the rat’s body via urine and feces in comparison to CrPic, as indicated by the values of the Cr retention index (44.4 vs. 65.9%, respectively). The additional dietary Cr, irrespective of its form and diet type, was not accumulated in the analyzed internal organs, i.e. brain, spleen, kidneys, liver, thigh bone, and thigh muscle. It should be stressed that dietary CrPic, unlike CrNPs, added to the high-fat diet adversely reduced plasma concentration of vital minerals in comparison to the levels observed in rats fed the low-fat diet, i.e. Zn (60.5 vs. 69.9 µM), Cu (13.6 vs. 15.7 µM), and P (1.12 vs. 1.30 µM). In turn, the CrNPs, but not CrPic, added to the high-fat diet decreased plasma Fe level (1.41 vs. 2.43 µM).

Źródło:

Polish Journal of Food and Nutrition Sciences; 2022, 72, 3; 229-238
1230-0322
2083-6007

Pojawia się w:

Polish Journal of Food and Nutrition Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

Seasonal Changes in Chromium Content in the Water of the Bystrzyca River (Dolnoslaskie Province)
Sezonowe zmiany zawartości chromu w wodzie rzeki Bystrzycy (województwo dolnośląskie)

Autorzy:

Senze, M.
Kowalska-Góralska, M.

Powiązania:

https://bibliotekanauki.pl/articles/387960.pdf

Data publikacji:

2012

Wydawca:

Towarzystwo Chemii i Inżynierii Ekologicznej

Tematy:

chrom
woda rzeczna
chromium
water rivers

Opis:

The study was conduct on the Bystrzyca river and its tributaries. The samples water were tested for chromium(VI). Chromium content in the waters covered by the study corresponded to that characteristic of surface waters in the areas of Poland with medium chromium pollution levels. Locally recorded higher concentrations were probably a result of discharges of municipal sewage or sewage from small industrial plant.
Badania prowadzono na rzece Bystrzycy i jej dopływach. W pobranych próbkach wody oznaczono zawartość chromu(VI). Zawartość chromu w badanych wodach utrzymuje się na poziomie charakterystycznym dla wód powierzchniowych obszaru Polski o średnim stopniu zanieczyszczenia chromem. Lokalnie notowane podwyższenia stężeń są najprawdopodobniej wynikiem miejscowych zrzutów ścieków komunalnych i pochodzących z niewielkich zakładów przemysłowych.

Źródło:

Ecological Chemistry and Engineering. A; 2012, 19, 4-5; 433-440
1898-6188
2084-4530

Pojawia się w:

Ecological Chemistry and Engineering. A

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

Use of dead and living fungal biomass for removal of hexavalent chromium

Autorzy:

Holda, A.
Mlynarczykowska, A.

Powiązania:

https://bibliotekanauki.pl/articles/109742.pdf

Data publikacji:

2016

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

hexavalent chromium
Aspergillus niger
biosorption
bioaccumulation

Opis:

The removal of hexavalent chromium from aqueous solution was carried out in batch experiments using dead and living biomass of Aspergillus niger. The effects of the operating parameters such as influent Cr(VI) concentration, influent pH and biomass concentration on the Cr(VI) reduction were investigated. The results indicates that the removal rate of Cr(VI) increased with a decrease in pH or with increase of Cr(VI) and biomass concentrations. For chromium bioaccumulation along with nutrients the process is the most intensive within the first 5 days of mycelium formation. For biosorption, the greatest binding of this metal is achieved within the first 4 days of the process.

Źródło:

Physicochemical Problems of Mineral Processing; 2016, 52, 2; 551-563
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Reduction and Biosorption of Cr(VI) from Aqueous Solutions by Acid- -Modifi ed Guava Seeds: Kinetic and Equilibrium Studies

Autorzy:

Ortíz-Gutiérrez, Marel
Alfaro-Cuevas-Villanueva, Ruth
Martínez-Miranda, Verónica
Hernández-Cristóbal, Orlando
Cortés-Martínez, Raúl

Powiązania:

https://bibliotekanauki.pl/articles/778567.pdf

Data publikacji:

2020

Wydawca:

Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie

Tematy:

Guava seeds
chromium reduction
biosorption
isotherms

Opis:

The use of guava seeds (GS) and acid-modified guava seeds (MGS) for the removal of Cr(VI) from aqueous solutions was investigated. Batch-type experiments were performed with Cr(VI) aqueous solutions and biosorbents to determine the kinetic and equilibrium sorption parameters. Results indicated that GS and MGS were capable of reducing and remove Cr(VI) from solutions, but the reduction was only observed at some experimental conditions. Infrared analysis showed that several functional groups were involved in the reduction, and biosorption of Cr(VI), particularly alcohol, phenolic, carboxylic, and methoxymethyl structures. The mechanisms of reduction and biosorption depended upon the type of biosorbent, pH, and temperature of the system. The pseudo-second-order kinetic model describes the kinetic sorption data, and the Langmuir-Freundlich (L-F) model describes the isotherm data in most cases. Significantly high total chromium biosorption capacities were obtained. Acid modification of guava seeds improves chromium biosorption performance.

Źródło:

Polish Journal of Chemical Technology; 2020, 22, 4; 36-47
1509-8117
1899-4741

Pojawia się w:

Polish Journal of Chemical Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

The effect of alloying method on the structure and properties of sintered stainless steel

Autorzy:

Dudek, A.
Lisiecka, B.
Ulewicz, R.

Powiązania:

https://bibliotekanauki.pl/articles/351870.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

sintered duplex stainless steel
chromium carbide

Opis:

Sintered duplex stainless steels (SDSSs) appear to be very interesting and promising materials that can be used in many industrial sectors. Ferrite improves material strength while austenite increases hardness and corrosion resistance. This study proposes a method to improve functional properties (e.g. hardness and wear resistance) by means of alloying the surface of the sintered duplex steel with Cr₃C₂ + 10% NiAl powder. The results of optical microscope metallography, SEM/EDX, XRD analysis and microhardness and wear resistance measurements are also presented. The surface alloying with Cr₃C₂ is a manufacturing method of surface layer hardening in sintered stainless steels and modification of surface layer properties such as hardness and coefficient of friction.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 1; 281-287
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

Combined Adsorption of the Copper and Chromium Cations by Clinoptilolite of the Sokyrnytsya Deposit

Autorzy:

Sabadash, Vira
Gumnitsky, Jaroslaw
Lyuta, Oksana

Powiązania:

https://bibliotekanauki.pl/articles/123357.pdf

Data publikacji:

2020

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

copper
chromium
heavy metals
adsorption
zeolite

Opis:

In the paper, the assessment of the impact of heavy metals on water objects, namely copper and chromium was performed, and the methods for their neutralization were defined. A scientifically grounded method for the selection of natural zeolite for the purification of wastewater from heavy metals has been developed, provided that they are jointly present. The physicochemical characteristics of two metals related to heavy metals are presented: copper and chromium. The methods for determining the sorption capacity of natural zeolite for copper and chromium compounds, as well as the methods of analytical control of the wastewater components were presented. The results of the experimental studies on the combined adsorption of copper and chromium cations by natural zeolite under static conditions were presented. The changes in the chemical composition of the zeolite surface as a result of heavy metal sorption have been investigated. The influence of the nature of the ions and the pH of the adsorption medium on the selectivity of the heavy metal ions extraction by zeolite was analyzed. A diagram of the composition of the solution, depending on the pH values, was constructed. The pH of the beginning of deposition of the corresponding heavy metal hydroxides on the zeolite surface was calculated. While analyzing the results of experimental studies on the combined adsorption of copper and chromium ions, it was found that the copper ions are significantly better adsorbed by the sorbent than the chromium ions. Despite the same concentration of the chromium and copper ions in solution, Cu²⁺ is extracted selectively. As can be seen from the results of experimental studies, the concentration of copper on the surface of the sorbent increases from 0.628% mass at a concentration of 0.01 g/dm³ to 47.380% mass at a concentration of 1 g/dm³. The studies on the static activity of clinoptilolite for the copper and chromium ions indicate a simultaneous mechanism of the process, which involves ion exchange and physical adsorption. The concentration of the chromium ions on the surface of the sorbent after adsorption depends on the increase of the concentration of Cr³⁺ in the original solution to a lesser extent. The results of the studies on the combined adsorption of the Cu²⁺ and Cr³⁺ ions indicate the possibility of their chromatographic separation, which makes their further use possible.

Źródło:

Journal of Ecological Engineering; 2020, 21, 5; 42-46
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

Influence of tungsten and titanium on the structure of chromium cast iron

Autorzy:

Kopyciński, D.
Piasny, S.

Powiązania:

https://bibliotekanauki.pl/articles/382431.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

żeliwo chromowe
węglik chromu
węglik tytanu
węglik wolframu
chromium cast iron
chromium carbide
titanium carbide
tungsten carbide

Opis:

The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear.

Źródło:

Archives of Foundry Engineering; 2012, 12, 1; 57-60
1897-3310
2299-2944

Pojawia się w:

Archives of Foundry Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Parametry stereologiczne węglików na przekroju odlewu z modyfikowanego żeliwa chromowego
Stereological parameters of carbides on section of casting made from modified chromium cast iron

Autorzy:

Studnicki, A.
Suchoń, J.

Powiązania:

https://bibliotekanauki.pl/articles/379480.pdf

Data publikacji:

2011

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

żeliwo chromowe
węglik chromu
parametr stereologiczny
odlew modelowy
chromium cast iron
chromium carbide
stereological parameter
model casting

Opis:

W artykule przedstawiono analizę parametrów stereologicznych węglików na przekroju odlewu modelowego wykonanego z modyfikowanego (mieszanina FeNb+FeV+MZR) żeliwa chromowego odpornego na zużycie ścierne . Zaobserwowano skokową zmianę niektórych parametrów stereologicznych węglików w pewnej odległości od powierzchni odlewu.
The analysis of stereological parameters of carbides on the section of the model casting made from modified (the mixture FeNb+FeV+RE) wear resistance chromium cast iron was introduced in the article. The jump change of some stereological parameters of carbides in certain distance from the surface of the casting was observed.

Źródło:

Archives of Foundry Engineering; 2011, 11, 3 spec.; 209-214
1897-3310
2299-2944

Pojawia się w:

Archives of Foundry Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Soil dehydrogenase activity in the presence of chromium [III] and [VI]

Autorzy:

Stepniewska, Z.
Wolinska, A.

Powiązania:

https://bibliotekanauki.pl/articles/25134.pdf

Data publikacji:

2005

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Tematy:

chromium
metal
soil material
microorganism
dehydrogenase activity

Źródło:

International Agrophysics; 2005, 19, 1
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Kinetic studies for the biosorption of chromium using cherry leaves (Muntingia calabura L.)

Autorzy:

Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.

Powiązania:

https://bibliotekanauki.pl/articles/10873.pdf

Data publikacji:

2014

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

kinetics
biosorption
chromium
cherry
leaf
Muntingia calabura

Opis:

Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.

Źródło:

International Letters of Natural Sciences; 2014, 20
2300-9675

Pojawia się w:

International Letters of Natural Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Selective chromium III/VI separation in polymer inclusion membrane system

Autorzy:

Rajewski, J.
Religa, P.
Wojasiński, M.
Gierycz, P.

Powiązania:

https://bibliotekanauki.pl/articles/115544.pdf

Data publikacji:

2014

Wydawca:

Fundacja na Rzecz Młodych Naukowców

Tematy:

chromium separation
selectivity
D2EHPA
PIM

Opis:

Analyze of chromium(III) transport process from mixtures of Cr(III)/Cr(VI) ions with polymer inclusion membrane (PIM) system have been done. Di(2-ethylhexyl) phosphoric acid (D2EHPA) have been used as a carrier. It was found that the transport efficiency in PIM is dependent on the carrier concentration in the membrane. It was found that there is an optimal range of carrier concentration in the membrane, which ensures rapid and efficient transport. In studied system optimal D2EHPA concentration was in range between 0,9- 1,5 mol/dm3. Membrane worked as selective barrier for Cr(VI) ions. However increase of Cr(VI) concentration above 0,0005 mol/dm3 negatively influenced Cr(III) transport. It was caused by degradation of the polymer inclusion membrane made of cellulose triacetate (CTA) . Strongly oxidizing Cr(VI) ions can damage polymer inclusion membrane with CTA matrix. The chemical attack of strongly oxidant Cr(VI) ions could lead either to hydrolysis of the pendant acetyl group or to oxidation of polymer backbone leading to chain scission. Moreover, oxidation is accelerated at high concentration of Cr(VI) ions. The membrane containing D2EHPA as a carrier can be recommended for selective separation of Cr(III) ions only from diluted Cr(VI)/Cr(III) mixtures. However the polymer inclusion membrane need a change the polymer matrix.

Źródło:

Challenges of Modern Technology; 2014, 5, 1; 15-19
2082-2863
2353-4419

Pojawia się w:

Challenges of Modern Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 26.

Tytuł:

Nanocomposite chromium coatings on aluminum alloys

Autorzy:

Gidikova, N.
Valov, R.
Petkov, V.
Sułowski, M.
Witkowska, M.
Cempura, G.

Powiązania:

https://bibliotekanauki.pl/articles/391428.pdf

Data publikacji:

2017

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa

Tematy:

chromium coating
aluminum
nanodiamond particles
electrochemical plating

Opis:

Chromium coatings modified with nanodiamond particles were deposited on aluminum alloys. The concentration of the nanodiamond particles in the chrome plating electrolyte was from 5 to 25 g/l. The thickness of the layer varied between 30 and 70 μm. The layers were prepared with the same electrolytic conditions and were measured with a metallographic microscope. The maximum microhardness of the coating was 840 kg/mm². X-ray diffraction analysis was performed with a Siemens D500 apparatus using the Bragg-Brentano technique. The distribution of Cr, Al and O in the cross section was studied by SEM-EDS. It was found that the layers were homogenous – only consisted of chromium. The coatings were also studied for non-destructivity by X-ray 3D computed tomography. It was found that the coatings were intact and continuous along the section. In order to obtain the maximum yield of chromium and maximum thickness of the layer, the optimum nanodiamond particle concentration was 10 g/l.

Źródło:

Prace Instytutu Odlewnictwa; 2017, 57, 4; 241-244
1899-2439

Pojawia się w:

Prace Instytutu Odlewnictwa

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

The Effect of Organic Fertilisation of Liquid Manure and the PRP Fix Preparation on the Yield and Chemical Composition of Winter Rape Seeds and Spring Wheat Grain

Autorzy:

Możdżer, E.
Meller, E.
Sammel, A.

Powiązania:

https://bibliotekanauki.pl/articles/123495.pdf

Data publikacji:

2017

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

lead
cadmium
chromium
metal fraction
sewage sludge

Opis:

In 2011–2013, a field experiment was carried out at the Experimental Station of Cultivar Evaluation in Szczecin-Dąbie. The experiment aimed at determining the effect of slurry without and with addition of increasing PRP Fix preparation doses on the crop yields and some of their qualitative traits. The soil where the experiment was set up was slightly acidic (pH_KCL 5.95); nitrogen, phosphorus and potassium contents were 0.86, 1.55 and 2.70 g·kg^-1 d.m., respectively. The total content of macro-elements for this type of soil was average. The content of bioavailable forms of phosphorus, magnesium and sulphur was average, while that of potassium was high. The content of organic carbon in soil was low, while the C:N ratio was 10.2:1 and was average for that type of soils. The obtained results show that the applied fertilisation with slurry combined with PRP Fix preparation and PK fertilisation increased the yield of winter rape seeds and spring wheat grain and the content of macro-elements being examined in them. The yields of the test plants were larger in the fertilisation objects where fertilisation with slurry with addition of 8 kg PRP Fix preparation per 1 m³ slurry was applied, when compared to those where only mineral fertilisation or slurry was used. Winter rape seeds and spring wheat grain usually contained more nitrogen, phosphorus, potassium, magnesium, calcium and sulphur in the fertilisation objects being fertilised with slurry with PRP Fix preparation in the amount of 8 or 12 kg per 1 m³ slurry with additional PK fertilisation (experimental series II) compared to experimental series I without additional PK fertilisation. Differences in the content of macro-elements in test plants after application of the fertilisation scheme being used varied. These differences were not always significant.

Źródło:

Journal of Ecological Engineering; 2017, 18, 1; 139-146
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

Biosorption of Heavy Metals from Synthetic Wastewater by Using Macro Algae Collected from Iraqi Marshlands

Autorzy:

Bahaa, Shaymaa
Al-Baldawi, Israa Abdulwahab
Yaseen, Safaa Rasheed
Abdullah, Siti Rozaimah Sheikh

Powiązania:

https://bibliotekanauki.pl/articles/123810.pdf

Data publikacji:

2019

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

adsorption
Cladophora
copper
cadmium
chromium
aqueous solutions

Opis:

Biosorption is fast, effective and low cost process. It takes place in a wide range of temperature and it can be used for almost all types of heavy metals. The aim of this study was to investigate the ability of locally collected green macro algae to remove copper, chromium and cadmium from synthetic wastewater. The fresh algae were converted into dry powder as biosorbent. In the investigations, 1 g of macro algae powder was exposed to synthetic waste water contaminated with 10 mg/L concentration of copper, chromium and cadmium in separate exposure for 2 hours. The best removal efficiency for copper, chromium and cadmium were 70%, 80% and 85%, respectively, from the initial concentration of 10 mg/L. While macro algae are abundantly available in marshlands of south Iraq, it can be preferably utilized as biosorbent to remove heavy metals from the industrial wastewater.

Źródło:

Journal of Ecological Engineering; 2019, 20, 11; 18-22
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

Phytoextraction of Cr by maize (Zea mays L.) : the role of plant growth promoting endophyte and citric acid under polluted soil

Autorzy:

Ali, J.
Mahmood, T.
Hayat, K.
Afridi, M. S.
Ali, F.
Chaudhary, H. J.

Powiązania:

https://bibliotekanauki.pl/articles/204568.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

maize
phytoextraction
chromium
citric acid
Burkholderia vietnamiensis

Opis:

High chromium (Cr) toxicity has turned into a serious environmental concern. Cr contaminated agronomic soils negatively affect the growth and yield of crops. Current research was conducted to enhance the phytoextraction potential of maize by using Burkholderia vietnamiensis and citric acid (CA). Plants were subjected to three concentrations of Cr (0.86, 350, and 500 ppm). A pot experiment was conducted under greenhouse conditions with completely randomized design (CRD). After 72 days of experiment, plants were harvested to analyze the morphological and biochemical attributes of soil, bacteria and plant. Results revealed that plant fresh, dry biomass, root, shoot length and chlorophyll contents significantly increased by 56%, 50%, 58%, 78% and 60%, respectively, at 500 ppm Cr concentration in combine treatment of B. vietnamiensis and CA. Maize plants treated with both B. vietnamiensis and CA significantly increased the bioaccumulation (BA) of Cr up to 50% and translocation factor (TF) by 31%. Furthermore, superoxide dismutase (SOD), proline and peroxidase dismutase (POD) activities in leaves were markedly increased by 30%, 42% and 15%, respectively, when treated with CA. Current study reveals that exogenous co-application of B. vietnamiensis + CA enhance plant growth by alleviating heavy metal stress and accelerate the phytoextraction of Cr. Taking into account the heavy metal tolerance and accumulation capacity, Zea mays is suitable for phytoremediation of contaminated soils in combination with B. vietnamiensis and CA.

Źródło:

Archives of Environmental Protection; 2018, 44, 2; 73-82
2083-4772
2083-4810

Pojawia się w:

Archives of Environmental Protection

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Efficient chromium removal from aqueous solutions by precipitate flotation using rhamnolipid biosurfactants

Autorzy:

Shojaei, V.
Khoshdast, H.

Powiązania:

https://bibliotekanauki.pl/articles/110347.pdf

Data publikacji:

2018

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

kinetics
wastewater
chromium
rhamnolipid biosurfactant
precipitate flotation

Opis:

In the present research study, the efficient removal of hexavalent chromium from aqueous solutions by precipitate flotation method was investigated. The experiments were carried out with the use of ferrous sulfate as a precipitating agent for chromium and rhamnolipid bio surfactant (RL) as a precipitate collector. The effects of rhamnolipid and co-precipitate concentrations, aeration rate, solution pH, and salt addition on the chromium removal were studied using a full factorial design. The chromium removal and water recovery to foam products were analyzed as process responses. Statistical analyses showed that the effects of all factors on the chromium removal followed a non-linear trend with a peak at the middle level. After the process optimization, the maximum chromium removal of 96.75±0.3% was obtained at pH value of 8, RL/Cr ratio of 0.01, Fe/Cr ratio of 3, and aeration rate of 50 cm3/min. Addition of salt with different cationic and anionic groups negatively influenced the removal efficiency. Kinetic studies suggested that the process of chromium removal by the precipitate flotation followed the first-order process with a rate constant of about 0.018 sec-1. Given the good removal capacity and kinetics, rhamnolipid biosurfactants can be a promising environmental-friendly bio collector for the removal of chromium ions from aqueous solutions.

Źródło:

Physicochemical Problems of Mineral Processing; 2018, 54, 3; 1014-1025
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

Selective solvent extraction of some heavy metal ions from aqueous solutions by octafunctionalized resorcin[4]arenes

Autorzy:

Kończyk, Joanna
Dlugosz, Jan

Powiązania:

https://bibliotekanauki.pl/articles/110830.pdf

Data publikacji:

2020

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

solvent extraction
lead
chromium
calixresorcinarene
metal removal

Opis:

This paper presents the results of the study on the extraction capacity of 1,8,15,22-tetra(1- heptyl)resorcin[4]arene and its octasubstituted derivatives containing thiophosphoryl, ester and amide groups in the presence of Pb(II), Zn(II), Cd(II) and Cr(III) in solvent extraction process. Effects of the structure and concentration of the resorcinarene extractant and the composition of the aqueous phase as well as its acidity on the efficiency and selectivity of removal of the examined metal ions from model aqueous solutions were determined. The 1:1 stoichiometry for complexes formed between Pb(II) and Cr(III) and the octasubstituted resorcin[4]arenes was determined by classical slope analysis and loading test.

Źródło:

Physicochemical Problems of Mineral Processing; 2020, 56, 2; 271-285
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Chromium Ions Removal by Capacitive Deionization Process: Optimization of the Operating Parameters with Response Surface Methodology

Autorzy:

Issa, Zainab M.
Salman, Rasha H.

Powiązania:

https://bibliotekanauki.pl/articles/2202352.pdf

Data publikacji:

2023

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

capacitive deionization
electrosorption
carbon fibre
chromium
wastewater

Opis:

An innovative desalination method called electrosorption or capacitive deionization (CDI) has significant benefits for wastewater treatment. This process is performed by using a carbon fiber electrode as a working electrode to remove hexavalent chromium ions from an aqueous solution. The pH, NaCl concentration, and cell voltage were optimized using the Box-Behnken experimental design (BDD) in response surface methodology (RSM) to study the effects and interactions of selected variables. To attain the relationship between the process variables and chromium removal, the experimental data were subjected to an analysis of variance and fitted with a quadratic model. The optimum conditions to remove Cr(VI) ions were: pH of 2, a cell voltage of 4.3V, and NaCl concentration of 1.4 g/L. This study demonstrated that the carbon fiber electrode was very efficient in Cr(VI) ions removal and the BBD methodology was a practical and effective strategy for predicting the results of various experimental conditions during a CDI process for the removal of chromium ions.

Źródło:

Journal of Ecological Engineering; 2023, 24, 1; 51--65
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

The Problems in Achieving Sustainable Development in the Tannery Industry in Regard to Sewage Sludge Management

Autorzy:

Bień, J.
Celary, P.
Wystalska, K.

Powiązania:

https://bibliotekanauki.pl/articles/124152.pdf

Data publikacji:

2017

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

sustainable development
tannery industry
sewage sludge
chromium

Opis:

The paper discusses the issue of tannery sewage sludge management as one of the barriers in reaching sustainable development in the tanning industry. The Authors present the main characteristics, and its origins, of tannery sludge limiting the possibilities of their treatment and review the proposed solutions found in literature. The paper focuses on identifying the strong and weak points of the most commonly used methods used for sewage sludge treatment as well as presents some novel approaches which remain at laboratory stage.

Źródło:

Journal of Ecological Engineering; 2017, 18, 6; 13-20
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Fractionation of Heavy Metals (Pb, Cr and Cd) In Municipal Sewage Sluges from Podlasie Province

Autorzy:

Łukowski, A.

Powiązania:

https://bibliotekanauki.pl/articles/125087.pdf

Data publikacji:

2017

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

lead
cadmium
chromium
metal fraction
sewage sludge

Opis:

In the samples of fresh dehydrated sewage sludges from municipal treatment plants in Grajewo, Bielsk Podlaski, Sokółka, Dąbrowa Białostocka, Knyszyn, Mońki, Augustów, Suwałki, Sejny and Suchowola the following determinations were made: pH, pseudo-total content of Pb, Cd and Cr, organic matter and dry mass. The contents of the above-mentioned elements in fractions were evaluated using modified BCR method (four fractions: 1-acid soluble and exchangeable, 2-reducible, 3-oxidizable, 4-residual). The lead content (mean values) in particular fractions can be arranged quantitatively in a sequence: F4 (51.4%) > F2 (30.3%) > F3 (19.2%) > F1 (7.2%), in the case of cadmium: F4 (49.0%) > F2 (23.6%) > F3 (18.9%) > F1 (15.5%) and in the case of chromium: F4 (65.0%) > F3 (30.6%) > F2 (6.8%) > F1 (3.1%). Cumulative content of lead in mobile fractions (F1+F2+F3) ranged from 20.7% to 89.9%; for cadmium from 32.9% to 76.9% and for chromium from 27.5 to 58.6% of pseudo-total content.

Źródło:

Journal of Ecological Engineering; 2017, 18, 1; 132-138
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Quantitative analysis of stability of 9%Cr steel microstructure after long-term ageing

Autorzy:

Golański, G.
Jasak, J.
Zieliński, A.
Kolan, C.
Urzynicok, M.
Wieczorek, P.

Powiązania:

https://bibliotekanauki.pl/articles/353244.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

high-chromium martensitic steels
microstructure
carbide precipitation

Opis:

The paper presents the results of research on the microstructure of martensitic X10CrMoVNb9-1 (P91) and X13CrMoCo- VNbNB9-2-1 (PB2) steel subject to long-term ageing at the temperature of 620°C and holding times up to 30 000 hours. The microstructural tests of the examined steel types were performed using a scanning microscope Joel JSM - 6610LV and a transmission electron microscope TITAN 80 - 300. The stability of the microstructure of the investigated steels was analyzed using a quantitative analysis of an image, including measurements of the following: the density of dislocations inside martensite/subgrain laths, the width of martensite laths, and the mean diameter of precipitates. It has been concluded that during long-term ageing, the microaddition of boron in PB2 steel significantly influenced the slowing of the process of degradation of the martensitic steel microstructure, as a result of slowing the process of coagulation of M23C6 carbides and Laves phase. It had a favorable effect on the stabilization of lath microstructure as a result of retardation of the processes of recovery and polygonization of the matrix.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 1; 263-271
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

Removal of chromium from aqueous solutions using Derris indica wood based activated carbon. Adsorption batch studies

Autorzy:

Ulaganathan, S.
Govindan, V.

Powiązania:

https://bibliotekanauki.pl/articles/950040.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

adsorption
activated carbon
chromium
isotherms
adsorption kinetics
chromium removal
adsorpcja
węgiel aktywowany
chrom
izotermy
kinetyka adsorpcji
usuwanie chromu

Opis:

Adsorption efficiency in removal of chromium from waste water has been studied using Derris indica based activated carbon by conducting batch adsorption tests. Adsorption kinetics of chromium removal by Derris indica was examined by varying factors such as pH and concentration of synthetic solution and dosage of activated carbon. It has been found that the Derris indica based activated carbon is able to remove 80 mg/dm3 of chromium from aqueous solution by dosage of 0.8 g/150 cm3 with optimum contact time of 15 min. The isotherm data confirms with both Langmuir and Freundlich isotherm forms.

Źródło:

Environment Protection Engineering; 2013, 39, 3; 21-29
0324-8828

Pojawia się w:

Environment Protection Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

Microstructural characteristic of N2 shielding gas in coating FeCrC composite to the surface of AISI 1030 steel with PTA method
Wpływ zawartości azotu w gazie osłonowym na mikrostrukturę powłok FeCrC na stali AISI 1030 otrzymanych metodą napylania plazmowego

Autorzy:

Yildiz, T.
Kaya Gür, A.

Powiązania:

https://bibliotekanauki.pl/articles/351583.pdf

Data publikacji:

2011

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

napylanie plazmowe
modyfikacja powierzchni
węglik chromu
mikrostruktura
plasma transferred arc coating
surface modifications
chromium carbide
chromium nitrurs
microstructure

Opis:

In this study, FeCrC powder was alloyed on the surface of AISI 1030 steel with FeCrC powder having 70% Cr ratio with the Plasma Transferred Arc Welding Method. In the coating process performed with the Plasma Transferred Arc Welding Method, N2 gas at 1-3-5% ratio was added to the shielding gas. The coating layer was analysed using optical microscope (OM), scanning electron microscope (SEM), X-ray diffractogram (XRD) and X-ray energy dispersive spectrometer (EDS). As a result of optical microscope and microstructure analyses, it was determined that the coating layer and the sub-layer were connected to each other metallurgical and there were austenite ( γ), Fe-Cr, Fe23(C)6, and Cr7C3 phase and carbides and CrN in the structure.
W pracy badano nakładanie powłok z proszku FeCrC o zawartości 70% chromu na powierzchni stali AISI 1030 metodą PTA. W czasie nakładania powłoki zawartość azotu w gazie ochronnym wynosiła 1, 3, 5%. Uzyskane powłoki badane były za pomocą mikroskopii optycznej, skaningowej mikroskopii elektronowej, dyfrakcji rentgenowskiej i mikroanalizy rentgenowskiej. W oparciu o wyniki obserwacji i analiz mikrostruktury stwierdzono, że powłoka i warstwa pośrednia połączone są ze sobą metalurgicznie. Stwierdzono obecność austenitu, Fe-Cr, Fe23(C)6, Cr7C3 oraz węglików i CrN w mikrostrukturze.

Źródło:

Archives of Metallurgy and Materials; 2011, 56, 3; 723-729
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Modelowy opis separacji jonów Cr(III) z mieszaniny Cr(III)/Cr(VI) w układzie z ciekłą membraną immobilizowaną (SLM)
Model of Cr(III) separation from Cr(III)/Cr(VI) mixture in a supported liquid membrane system (SLM)

Autorzy:

Rajewski, J.
Zalewski, M.
Gierycz, P.

Powiązania:

https://bibliotekanauki.pl/articles/2073217.pdf

Data publikacji:

2015

Wydawca:

Stowarzyszenie Inżynierów i Techników Mechaników Polskich

Tematy:

separacja chromu
D2EHPA
SLM
chromium separation

Opis:

W pracy przedstawiono model matematyczny separacji jonów Cr(III) z mieszaniny Cr(III)/Cr(VI) przyjmując jako założenie, że efekt końcowy procesu transportu w SLM uzależniony jest głównie od nagromadzenia substancji pośrednich w membranie (typowa cecha reakcji następczych nieodwracalnych) Stwierdzono, iż obecność jonów Cr(VI) ma negatywny wpływ na kinetykę i efektywność separacji. Zwiększenie burzliwości układu niweluje niekorzystny wpływ jonów Cr(VI). W efekcie uzyskano zadowalającą kompatybilność wyników eksperymentalnych z przebiegami modelowymi.
Based on the assumption that a transport process result in the SLM, in particular, depends on accumulation of intermediate products in the membrane (a typical feature of consecutive first-order reactions), a mathematical model of Cr(III) from Cr(III)/Cr(VI) mixture separation is proposed. It was found that the presence of Cr(VI) has a negative impact on transport kinetics and separation efficiency. The increase of solution turbulence reduces this negative effect. A satisfactory compatibility of experiments and model results were obtained.

Źródło:

Inżynieria i Aparatura Chemiczna; 2015, 4; 198--200
0368-0827

Pojawia się w:

Inżynieria i Aparatura Chemiczna

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Zmiany stężenia chromu w wodzie zbiornika zaporowego w Lubachowie w okresie stagnacji letniej i zimowej
Changes of chromium concentration water of dam reservoir in Lunachow during suumer and winter stagnation

Autorzy:

Senze, M.
Kowalska-Góralska, M.

Powiązania:

https://bibliotekanauki.pl/articles/126190.pdf

Data publikacji:

2010

Wydawca:

Towarzystwo Chemii i Inżynierii Ekologicznej

Tematy:

chrom
zbiorniki zaporowe
woda
chromium
dam reservoirs
water

Opis:

Przeprowadzono badania zawartości chromu w wodzie zbiornika zaporowego Lubachów w okresie stagnacji letniej i zimowej. Stwierdzono niską zawartość chromu w wodzie, utrzymującą się na poziomie charakterystycznym dla wód powierzchniowych obszaru Polski o średnim stopniu zanieczyszczenia chromem.
Chromium contents in the water of the Lubachow dam reservoir were measured during summer and winter stagnation. Its accumulation was low, the level was like in waters of Polish medium polluted water area.

Źródło:

Proceedings of ECOpole; 2010, 4, 2; 483-487
1898-617X
2084-4557

Pojawia się w:

Proceedings of ECOpole

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

Effect of Alloying Elements on Properties and Structure of High Chromium Cast Irons

Autorzy:

Kaňa, V.
Záděra, A.
Krutiš, V.

Powiązania:

https://bibliotekanauki.pl/articles/351222.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

high chromium cast irons
wear resistance
carbides
refinement

Opis:

The paper deals with hypereutectic high chromium cast irons. The subject of examination was the effect of various alloying elements (Ti, W, Mo, V) on the size of primary carbides and on the resultant material hardness. Using a scanning electron microscope with a wave dispersion analyser, the carbon content in carbides was established. To determine the other elements, an energy dispersion analyser was used. It was found that both the primary and the eutectic carbides were of the M₇C₃ type and very similar in composition. The carbides always contained Cr and Fe, and also W, Mo, V or Ti, in dependence on the alloying elements used. The structure of materials containing only chromium without any alloying additions exhibited coarse acicular primary carbides. The structure of materials alloyed with another element was always finer. Marked refinement was obtained by Ti alloying.

Źródło:

Archives of Metallurgy and Materials; 2018, 63, 2; 609-614
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Composite Coatings of Chromium and Nanodiamond Particles on Steel

Autorzy:

Gidikova, N.
Sulowski, M.
Petkov, V.
Valov, R.
Cempura, G.

Powiązania:

https://bibliotekanauki.pl/articles/356289.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

composite chromium coating
nanodiamond particles
SEM-EDS analysis

Opis:

Chrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 4; 2421-2424
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

The Effect of Fe-Ti Inoculation on Solidification, Structure and Mechanical Properties of High Chromium Cast Iron

Autorzy:

Kopyciński, D.
Siekaniec, D.
Szczęsny, A.
Guzik, E.
Nowak, A.

Powiązania:

https://bibliotekanauki.pl/articles/353234.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

high chromium cast iron
inoculation
titanium
mechanical properties

Opis:

The results of studies of the effect of different amounts of the Fe-Ti inoculant on structure and selected mechanical properties of High Chromium Cast Iron (conventionally abbreviated as HCCI) are presented. The main purpose of the inoculation is structure refinement and hence the improvement of casting properties. Generally considered a strong carbide-forming element, titanium is an effective inoculant for the high chromium cast iron. However, there is an optimal amount of titanium addition beyond which the mechanical properties begin to deteriorate. The studies enabled determining the amount of Fe-Ti inoculant optimal for the cast iron of a given chemical composition.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 4; 2183-2187
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

Biological removal of Cr(VI) ions from aqueous solutions by trichoderma viride

Autorzy:

Holda, A.
Kisielowska, E.

Powiązania:

https://bibliotekanauki.pl/articles/109693.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

bioaccumulation
chromium
Cr(VI)
microscopic fungi
Trichoderma viride

Opis:

The paper presents biological removing of Cr(VI) ions from aqueous solution by applying autochtonic fungi seedling of Trichoderma viride originated from chromium mud samples. The growth of organism and removing of chromium(VI) was performed in aqueous solution of various chromium(VI) contents and at optimal value of pH. During 14 days of incubation, samples of 5 cm3 each were collected every day for determination of chromium(VI) in solution and the efficiency of biological removal was specified. Since removal of chromium(VI) from aqueous solution may occur because of reduction, biosorption or bioaccumulation processes, to determine which one occurred, the Cr(III) contents were determined in samples of the medium as well in ooze after mycelium irrigating and in mycelium.

Źródło:

Physicochemical Problems of Mineral Processing; 2013, 49, 1; 47-60
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Electrolyte coatings of chromium with nanodiamonds on sintered steels

Autorzy:

Gidikova, N.
Valov, R.
Petkov, V.
Salamci, E.
Bilgili, Z.
Unal, R.

Powiązania:

https://bibliotekanauki.pl/articles/391723.pdf

Data publikacji:

2017

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa

Tematy:

sintered products
chromium coating
wear resistance
corrosion resistance

Opis:

Sintered ferrous components were coated with electrochemical chromium coatings modified with nanodiamond particles. The nanodiamond particles were produced by detonation synthesis with an average grain size 8 nm. The objective of this study was to determine the tribological properties and the corrosion resistance of sintered iron samples coated with an electrochemically deposited chromium layer modified with nanodiamond particles. The thickness of the obtained composite coatings was more than 25 μm. The microstructure and microhardness were determined by metallographic methods. The mechanical and chemical properties of the samples were compared to uncoated samples prepared from the same iron powder. The microhardness was 5 times higher, the wear resistance increased 6 times and the corrosion resistance in 0.1 M NaCl solution was 10 times higher.

Źródło:

Prace Instytutu Odlewnictwa; 2017, 57, 4; 333-336
1899-2439

Pojawia się w:

Prace Instytutu Odlewnictwa

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

Chromium induced changes in Soybean (Glycine max L.) metabolism

Autorzy:

Sundarmoorthy, P.
Sankarganesh, K.
Selvaraj, M.
Baskaran, L.
Chidambaram, Al. A.

Powiązania:

https://bibliotekanauki.pl/articles/1193974.pdf

Data publikacji:

2015

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

Chromium
biochemical contents
enzymatic activities
morphology
soybean seedlings

Opis:

Pulses play an important role in Indian agriculture. Among the pulses, soybean (Glycine max. L) occupies a unique place by becoming the largest source of vegetable oil and protein. It is widely cultivated in India and occupy 5th largest production of soybean in the world. Industrialization and population explosion has caused a serious problem of pollution in the environment in all possible ways. As a result, most of the water resources are getting polluted by receiving large quantity of sewages and industrial wastewaters with heavy metals. In some places, these polluted water is being used for irrigation due to scarcity for good water. The continuous use of these wastewater containing heavy metals degraded the soil quality and reduced the growth and yield performance of agricultural crops. Aresenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, uranium, vanadium and zinc are the some of the important heavy metals found in our environment. Among the heavy metals, chromium merits a special reference for its toxic potential. It is released from the industries such as electroplating, leather tanning, textile printing and metal finishing. It is one of the main constitutions of tannery effluent. Presence of excess amount of chromium in the wastewater affect the plant growth and development when it is used for irrigation. So, Laboratory study was carried to investigate the irrigational impact of various concentrations of Cr (5, 10, 25, 50 100, 200 and 300 µg/l) on changes in morphological (germination percentage, root length, shoot length, fresh weight and dry weight), photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, carotenoid) biomolecules (aminoacid, protein, sugar, proline) and antioxidant enzymatic activities (catalase, peroxidase, polyphenol oxidase and super oxide dismutase) were estimated. The accumulation of chromium in soybean seedlings were estimated and they were correlated with the above mentioned parameters.

Źródło:

World Scientific News; 2015, 16; 125-158
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Kinetic modeling of chromium(III) extraction with aliquat 336 from alkaline aqueous solutions containing chlorides

Autorzy:

Wionczyk, B.

Powiązania:

https://bibliotekanauki.pl/articles/110327.pdf

Data publikacji:

2013

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

extraction
chromium(III) chloride
Aliquat 33
kinetic analysis

Opis:

The effects of time, composition and history of preparation of the aqueous phase on the liquidliquid extraction of chromium(III) with Aliquat 336 from the aqueous alkaline solutions containing chlorides were studied. At time far from the equilibrium the yield and initial rate of the chromium(III) extraction depend on NaOH concentration, ionic strength of the aqueous phase and the way of its preparation. At the constant composition of the feed solution, rate of the Cr(III) extraction in approach to the equilibrium is higher when chromium(III) is extracted from the alkaline aqueous phase freshly prepared by direct dissolution of a weighted sample of CrCl3 than from that obtained by dilution of aged stock solution of CrCl3. Kinetic analysis by the mathematical models showed that within the whole period of time needed to reach the equilibrium, the rate of the Cr(III) extraction is limited by the second-, and third-order chemical reaction towards Cr(III), irrespective of composition and preparation history of the aqueous phase. The three-dimensional diffusion and chemical reaction at phase boundary substrateproduct (the contracting volume) models have a significant effect on the chromium(III) extraction within the initial extent of the process.

Źródło:

Physicochemical Problems of Mineral Processing; 2013, 49, 2; 587-605
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

Characteristics and Adsorption Test of Activated Carbon from Indonesian Bituminous Coal

Autorzy:

Kusdarini, Esthi
Budianto, Agus

Powiązania:

https://bibliotekanauki.pl/articles/2202119.pdf

Data publikacji:

2022

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

ammonium phosphate
coal
batik waste
activated carbon
chromium

Opis:

The fast-growing batik industry in Indonesia raises the problem of the waste containing chromium. One method to remove chromium is by the adsorption process using activated carbon. Activated carbon can be made from coal. This commodity is a mining mineral the availability of which is still abundant in Indonesia. This study aimed to obtain: 1) the best concentration of activator and activation temperature in the manufacture of activated carbon; 2) characteristics of activated carbon (moisture content, volatile matter content, ash content, fixed carbon content, iodine number, specific surface area, pore-volume, pore surface area, pore radius, and SEM photos); 3) % activated carbon removal for chromium and maximum adsorption capacity for chromium; 4) Freundlich and Langmuir isotherm adsorption equation of activated carbon to chromium. The manufacture of activated carbon was carried out by a carbonization process followed by a chemical and physical activation processes. The chemical activator was ammonium phosphate with doses of 74.5 g/L, 149 g/L, 223.5 g/L, and 298 g/L. Meanwhile, physical activation was carried out at 848 K, 948 K, 1048 K, and 1148 K. The next step was to test the adsorption capacity of activated carbon on artificial batik waste containing chromium. The results showed that: 1) activator concentration did not significantly affect the characteristics of activated carbon. Meanwhile, the optimal activation temperature is at a temperature of 1048 K and 1148 K, which can produce the activated carbon that meets the requirements of activated carbon of the Indonesian National Standard 06-3730-1995 with the following contents: air content 0.16–0.81%; volatile matter 14.62–19.31%; ash 6.48–9.97%; fixed carbon 70.60–75.79%; iodine number 1243.13–1258.65%; specific surface area 31.930 m2/g; activated carbon pore volume 0.011 cc/g; pore surface area 8.905 m2/g; activated carbon pore radius 30.614; 3) the proportion of activated carbon removal for chromium is 37–53% and the maximum adsorption capacity for chromium is 52 mg/g; 4) the Freundlich equation test resulted in a constant R2 of 0.5126, n 2.4870, KF 8.8818 mg/g, while the Langmuir equation test resulted in a constant R2 of 0.8897, b -0.0075 L/mg, qm -90.0901 mg/g.

Źródło:

Journal of Ecological Engineering; 2022, 23, 10; 129--138
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 48.

Tytuł:

Chromium Elimination from Contaminated Soil by Electro-Kinetic Remediation, Using Garlic Peels Powder

Autorzy:

Hawal, Laith Hamdan
Al-Sulttani, Ali Omran
Kariem, Nagam Obaid

Powiązania:

https://bibliotekanauki.pl/articles/1955434.pdf

Data publikacji:

2021

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

chromium
soil
electrokinetic
removal percentage
garlic peels powder

Opis:

In this paper, an electro-kinetic technique was applied to remove chromium from contaminated soil. This technique is appropriate for the soils with low permeability. Various experiments were carried out under different operating conditions, including various purging solutions. Garlic peels powder (GPP) was used in this study as a cheap adsorbent substance to avert the flow of reverse osmosis, which may affect the removal percentage. The results proved that the removal percentage increased as the pH of the purging solutions decreased. The first three experiments were performed with purging solution at pH of 4, 6, and 8 respectively. The highest removal percentage was 66.3% at pH of 4 compared to the other two experiments at pH of 6 and 8, where the removal percentages were 53.3% and 49.7%, respectively. This paper showed that the percentage of chromium removal decreased along with the voltage. The removal percentage at 1.5 V/cm was 66.3%, while at 1 V/cm was 61%. Garlic peels powder (GPP) is considered as an effective adsorbent material to avert the reverse osmosis flow. Therefore, the use of this material in this study will give a new impression on the application of these products as an absorbent medium.

Źródło:

Journal of Ecological Engineering; 2021, 22, 7; 252-259
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:

Novel lignocellulosic wastes for comparative adsorption of Cr(VI): equilibrium kinetics and thermodynamic studies

Autorzy:

Haroon, H.
Gardazi, S. M. H.
Butt, T. A.
Pervez, A.
Mahmood, Q.
Bilal, M.

Powiązania:

https://bibliotekanauki.pl/articles/778473.pdf

Data publikacji:

2017

Wydawca:

Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie

Tematy:

chromium VI
equilibrium kinetics
lignocellulosic waste adsorbents
thermodynamics

Opis:

Cr(VI) adsorption was studied for abundantly available low-cost lignocellulosic adsorbents in Pakistan namely, tobacco stalks (TS), white cedar stem (WCS) and eucalyptus bark (EB). Several process variables like contact time, adsorbent dose, pH, metal concentration, particle size and temperature were optimized in batch mode. EB showed high Cr(VI) adsorption of 63.66% followed by WCS 62% and TS 57% at pH 2, which is higher than most of the reported literature. Langmuir isotherm (R²  = 0.999) was well fitted into the equilibrium Cr(VI) data of EB, suggesting homogeneous active sites and monolayer coverage of Cr(VI) onto the EB surface. Freundlich (R²  = 0.9982) isotherm was better fitted to the equilibrium data of TS and WCS, revealing the adsorption sites with heterogeneous energy distribution and multilayer Cr(VI) adsorption. Moreover, the Cr(VI) adsorption of studied adsorbents followed the pseudo-second order kinetic model. Thermodynamic properties were investigated in two temperature ranges, i.e., T₁  (303–313 K) and T₂  (313–323 K). TS and EB showed the exothermic at T1 and endothermic reactions at T2 with entropy controlled adsorption at the solid-liquid interface, and WCS exhibited an opposite thermal trend with decreasing disorderness at solid-liquid interface as temperature rises. Gibbs free energy (ΔG>0) confirmed the non-spontaneous adsorption process for all studied adsorbents.

Źródło:

Polish Journal of Chemical Technology; 2017, 19, 2; 6-15
1509-8117
1899-4741

Pojawia się w:

Polish Journal of Chemical Technology

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Reduction of Total Chromium Levels from Raw Tannery Wastewater via Electrocoagulation using Response Surface Methodology

Autorzy:

Aguilar-Ascón, Edwar
Marrufo-Saldaña, Liliana
Neyra-Ascón, Walter

Powiązania:

https://bibliotekanauki.pl/articles/124384.pdf

Data publikacji:

2019

Wydawca:

Polskie Towarzystwo Inżynierii Ekologicznej

Tematy:

chromium
electrocoagulation
tannery wastewater
aluminum electrodes
response surface

Opis:

This study focused on reducing total chromium levels in raw wastewater from the leather tanning industry via electrocoagulation to comply with maximum permissible limits (MPL) and to determine the effects of main process parameters. An electrocoagulation reactor was built using aluminum electrodes as an anode and cathode. Then, the response surface methodology was applied using a 3^k factorial design considering three factors, namely current intensity, treatment time, and pH. The total chromium removal percentage was considered as a response variable. 99% of the total chromium found in wastewater could be removed after 14-min treatment at 2-A current intensity and pH 5.5. Similar amount of chromium was removed at pH of 8.5 and 7. Statistical analysis performed at a confidence level of p < 0.05 revealed that all three factors influenced electrocoagulation. Total chromium could be efficiently removed from raw wastewater at a current intensity of 2.9 A, a pH of 8.4, and a treatment time of 21 min, suggesting that electrocoagulation using aluminum electrodes is an efficient method for total chromium removal. Thus, this process must be considered as a solution to the problems caused by the leather tanning industry and for better compliance with the MPL established in the Peruvian environmental standards.

Źródło:

Journal of Ecological Engineering; 2019, 20, 11; 217-224
2299-8993

Pojawia się w:

Journal of Ecological Engineering

Dostawca treści:

Biblioteka Nauki

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