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Wyszukujesz frazę "chemical extraction" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Purification of feldspar from colored impurities using organic acids
Autorzy:
Vapur, H.
Top, S.
Demirci, S.
Powiązania:
https://bibliotekanauki.pl/articles/110202.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chemical extraction
feldspar
organic acids
statistical analysis
microwave
Opis:
In this study oxalic, citric, and glycolic acids were used in order to reduce Fe and Ti (colored impurities) from the slimes (-75 μm) feldspar samples using organic acids. The results showed that removal ratios of the colored impurities from the feldspar samples were 67.9% for Fe and 43.75% for Ti using oxalic acid and the agitated leaching (AL) method. The influence of main parameters (temperature, pulp density, leaching time, and acid concentration) were examined by using full the factorial design (24) ANOVA-Yates test technique. Next, the removal ratios of Fe% and Ti% in the tests were determined to be 80.44% and 45.39%, respectively. Additionally, the main parameters which were obtained from the best results of AL were optimized for the -500+75 μm feldspar sample. Finally, the microwave-assisted pressure leaching (MAPL) method was apply to determine the effect of pressure on leaching. The obtained results indicated that the optimum removal ratios obtained were 95.74% for Fe and 70.88% for Ti by using the MAPL tests with oxalic acid. Furthermore, the measured whiteness (L) values were observed to be over 90%. This is a suitable purification ratio for the ceramic and glass industry.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 150-160
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamika ekstrakcji Zn, Cu, Ni, Pb i Cd z przemysłowych i komunalnych osadów ściekowych przy zastosowaniu roztworów EDTA i kwasu cytrynowego
Dynamics of Zn, Cu, Ni, Pb and Cd Extraction from Industrial and Municipal Sewage Sludge Using EDTA and Citric Acid Solutions
Autorzy:
Karwowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/1818058.pdf
Data publikacji:
2016
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
osady ściekowe
metale ciężkie
ekstrakcja chemiczna
EDTA
kwas cytrynowy
sewage sludge
heavy metals
chemical extraction
citric acid
Opis:
Sewage sludge generated in wastewater treatment plants accumulates varied contaminations of inorganic as well as organic character. Among them, heavy metals constitute a group of chemical substances which are highly dangerous for natural environment, because of the possibility of their mobilization and migration in environment as a result of changes in surrounding system. Moreover, they are pollutants toxic for humans, non-biodegradable and accumulate in living organisms. In recent years, there has been a great interest in the removal of heavy metals from sewage sludge with different chemical compounds solution and especially metal chelating agents. The goal of this work was to determine the optimal time for extraction of selected metals (Zn, Cu, Cd, Ni, Pb) from contaminated industrial and municipal sewage sludge by using 0.1 M solutions of EDTA (disodium salt of ethylenediaminetetraacetic acid), as well as citric acid. The analyzed wastewater sludge was collected from metallurgic industry treatment plant and from municipal wastewater treatment plant. In sewage sludge samples, the principal parameters were determined and after mineralization with mixture of concentrated mineral acids: HNO3 and HCl (1 : 3) the total content of analyzed heavy metals was detected using atomic absorption spectrophotometry. Chemical extraction of metals from sewage sludge 5 g samples was carried out with 50 c3 portions of 0.1M EDTA and citric acids solution for different periods of time, i.e. from 0.5 to 24 hours. After given time of shaking, the liquids were decanted, filtered through a filter paper, and finally the extracts were analyzed for heavy metals content with AAS method. It was observed that both applied solutions effectively washed metals from studied sewage sludge samples. For the period of time from 0.5 up to 5.0 hours, the concentration of almost all metals increased linearly and in the 6th hour of extraction the process was limited and finally for the period of time from 8.0 up to 24 hours, the detected metal contents in extracts were practically the same. The analysis of dependences of metal concentration versus time of extraction yielded in the optimal time of process, what value was determined as equal to 6 hours. The efficiencies of the metals removal from the studied sewage sludge by mans of the analyzed solutions of extractants were compared. Copper and lead reached higher concentration in liquids after EDTA extraction. It indicated that EDTA solution was a more effective extractant for the afore-mentioned metals. The concentration of zinc was higher in citric acid solution and citric acid was determined as more effective compound for zinc removal. For nickel and cadmium, the concentrations of metals were similar in both type of washing solution, which indicated that the efficiencies of both solutions were comparable.
Źródło:
Rocznik Ochrona Środowiska; 2016, Tom 18, cz. 2; 681-694
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of various organic fertilisers on the heavy metal fractions in the soil. Part 3. Zinc, manganese and iron
Autorzy:
Filipek-Mazur, B
Gondek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1449514.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
iron
manganese
chemical extraction
soil
organic material
zinc
soil property
degraded ecosystem
anthropogenic ecosystem
organic fertilizer
heavy metal
Opis:
The paper presents distribution of zinc, manganese and iron in fractions of soil treated with tannery sludge and compost of tannery sludge and peat, and, for the sake of comparison, the soil from a plot treated with farmyard manure (FYM), and mineral fertilisers. Total soil contents of zinc ranged from 38.0 to 47.3 mg kg-1 of soil. The share of mobile zinc forms ranged between 6.05-7.93%. Percentage of the exchangeable form was between 5.8-7.5% of the total Zn contents, while the share of forms bound with organic matter ranged between 10.7 and 12.7%. A considerable part of zinc was bound with manganese and iron oxides. Between 30.14- 43.72% of Zn were found in the residual form. Organic and mineral treatment influenced the share of easily soluble manganese compounds. It ranged between 15.6-19.7%. The least of manganese (1.0-2.0%) occurred in the compounds with crystalline iron oxides. The exchangeable form constituted between 3.4-4.2%, organic fraction accumulated slightly more. Manganese oxides retained the most of the element. Trace amounts of iron were revealed in the first three fractions. The biggest part of this metal was found in sparingly soluble compounds, mainly oxides (over 40%) and on residual fraction (over 30%).
Źródło:
Acta Agrophysica; 2001, 51; 215-220
1234-4125
Pojawia się w:
Acta Agrophysica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimalization of Metals Ions Extraction from Industrial Wastewater Sludge with Chelating Agents
Optymalizacja procesu ekstrakcji jonów metali z przemysłowych osadów ściekowych za pomocą roztworów związków chelatujących
Autorzy:
Karwowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/204854.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
osad ściekowy
metale ciężkie
ekstrakcja
kwas cytrynowy
EDTA
metallurgical wastewater sludge
ions of metals
citric acid
chemical extraction
Opis:
The report presents the results of selected heavy metals (Zn, Cu, Cd, Ni, Pb) removal from industrial wastewater sludge collected from metallurgy industry. As washing solutions two chelating agents were used: EDTA and citric acid. The study was focused on 0.000 (deionized water), 0.010, 0.050, 0.075, 0.100 M and 0.000, 0.050, 0.100, 0.500, 1.000 M, EDTA and citric acid solutions, respectively. Efficiency of EDTA and citric acid solutions for metal removal was studied by extraction of sludge samples with chelators. Chemical extraction of selected metals was effective for both types of solution. Optimal concentration of EDTA was 0.100M for Zn, Ni and Cd, 0.075 M for Cu and Pb. Optimal concentration of citric acid was 0.500 M for all analyzed metals
W skali roku generowane są na oczyszczalniach ścieków ogromne ilości osadów, które kumulują wiele szkodliwych substancji zarówno organicznych, jak i nieorganicznych. Pośród nich szczególne zagrożenie dla środowiska stanowią jony metali ciężkich. Podstawowe kierunki zagospodarowania osadów ustalają limity zawartości metali ciężkich. Z kolei przetrzymywanie osadów na składowiskach innych niż składowisko odpadów niebezpiecznych jest w znacznym stopniu ograniczone przez wymogi Dyrektywy Unii Europejskiej 99/31/EC. Celem badań było określenie optymalnych warunków prowadzenia ekstrakcji metali ciężkich (Zn, Cu, Cd, Ni, Pb) z osadów ściekowych przy użyciu wybranych ekstrahentów jak EDTA (kwas etylenodiaminotetraoctowy) i kwas cytrynowy. Osady ściekowe pochodziły z oczyszczalni ścieków przemysłowych zakładu metalurgicznego. W osadach całkowitą zawartość metali ciężkich oznaczono, po mineralizacji wodą królewską, metodą ASA. Efektywność wodnych roztworów EDTA i kwasu cytrynowego w wymywaniu badanych metali ciężkich określano poprzez ekstrakcję próbek wodą demineralizowaną, roztworem EDTA o stężeniach: 0.010, 0.050, 0.075, 0.100 M oraz kwasu cytrynowego o stężeniach: 0.050, 0.100, 0.500 oraz 1.000 M. Ekstrakcję prowadzono przez 6 godzin w temperaturze pokojowej. W uzyskanych ekstraktach oznaczono zawartość metali ciężkich metodą ASA. Badane osady były znacznie zanieczyszczone metalami. Oznaczone całkowite zawartości cynku, miedzi, kadmu, niklu i ołowiu wynosiły odpowiednio: 3665.0, 112.5, 3.2, 85.0 oraz 120.3 mg/kg s.m.o. Zarówno EDTA, jak i kwas cytrynowy okazały się efektywnymi ekstrahentami badanych metali, przy czym optymalne stężenia dla prowadzenia procesu wyniosły odpowiednio 0.075 oraz 0.500 M. Porównując stopień usunięcia metali z badanych osadów ściekowych przez roztwory o takim samym stężeniu (0.100 M) stwierdzono, że efektywniejszym ekstrahentem dla miedzi i ołowiu okazał się roztwór EDTA, a dla cynku kadmu i niklu roztwór kwasu cytrynowego.
Źródło:
Archives of Environmental Protection; 2012, 38, 4; 15-21
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of various organic fertilisers on the heavy metal fractions in the soil. Part 2. Chromium and cadmium
Autorzy:
Filipek-Mazur, B
Gondek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1449480.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
chromium
chemical extraction
soil
cadmium
organic material
soil property
degraded ecosystem
anthropogenic ecosystem
organic fertilizer
agricultural chemistry
heavy metal
Opis:
The subject of the paper was to determine chromium and cadmium fractions in the soils treated with tannery organic materials. Methods, characteristics of experimental materials and the tested soils were presented in the first part of the paper. After four years of investigations soil samples were collected for the assessment of the total content of chromium and cadmium and their fractions. Results of a sequential chemical extraction confirmed literature data on the weak mobility of this metal in the soil. After application of the studied fertilisers, the share of the most mobile Cr fractions was slight. Iron oxides and residual fractions were most important for chromium accumulation. Cadmium mobility in the soil and its easy uptake by plants is related to a considerable share of mobile forms. A large share of mobile form was noticed in the analysed soils (54.5-68.3%). Exchangeable fraction bound smaller amounts of cadmium (6.8-13.2%). Similar amounts of cadmium were accumulated in the fractions bound to manganese oxides (8.5-19.6%). Organic matter did not contribute to this element binding and the amounts of cadmium stored in this fraction were 2.3-6.6%. Only very small amount of cadmium was accumulated in the form bound with the initial minerals.
Źródło:
Acta Agrophysica; 2001, 51; 209-214
1234-4125
Pojawia się w:
Acta Agrophysica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of various organic fertilisers on the heavy metal fractions in the soil. Part 1. Lead, copper and nickel
Autorzy:
Filipek-Mazur, B
Mazur, K.
Gondek, K.
Powiązania:
https://bibliotekanauki.pl/articles/1449430.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
chemical extraction
soil
organic material
soil property
copper
lead
degraded ecosystem
anthropogenic ecosystem
nickel
organic fertilizer
agricultural chemistry
heavy metal
Opis:
The present investigations aimed at determining the effect of various organic materials, i.e. farmyard manure (FYM), organic tannery sludge and compost of such sludge and peat on lead, copper and nickel fractions content in soil. Doses of peat compost and organic sludge were calculated according to the nitrogen amount per a FYM dose. After four years of experiment, fractions of Pb, Cu and Ni compounds were assessed in the soil from individual plots using the Zeien and Brummer's sequence chemical extraction method. Heavy metal contents were determined using a ICP-AES in JY 238 Ultrace apparatus. Lead accumulated mainly in the form bound with organic matter and with amorphic iron oxides. This metal distribution reveals its slight share in the mobile and exchangeable forms. Composts and sludge introduced into the soil did not affect any significant changes of the individual lead forms share as compared to FYM and NPK treated plots and the control. Some amount of copper occurred as mobile forms in all the soils. In the soil of all the treated plots, copper occurred mainly bound with organic matter and amorphic iron oxides. The basic share of nickel was found in the residual fraction bound with internal crystalline nets of initial elements. Beside the residual form, nickel was connected mainly with organic matter.
Źródło:
Acta Agrophysica; 2001, 51; 201-208
1234-4125
Pojawia się w:
Acta Agrophysica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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