Wyniki wyszukiwania - Biblioteka Nauki

1

Speciation analysis of As(III)and As(V) in soil samples from the area of the chemical plant in Luboń near Poznań

100%

Kozak L. , Niedzielski P.

Archives of Environmental Protection

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2008

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tom Vol. 34, no. 2

95-103

EN

Arsenic content was determined in the soil profiles collected from the former dumping ground of post-crystallization lye (presently under recultivation) in the area of the chemical plant in Luboii. near Poznań. Of particular concern was the content of the two most toxic species of As(lll) and As( V) in the environmentally available exchange fraction. Extraction was performed with a phosphate buffet of pH = 6.0 š 0.2, and the analytical method applied was IIPLC-HG-AAS. As(V) species were found in all samples, whereas As(lll) species in a few samples collected at different depths. The concentration of As(V) varied from 91 to 1228 ng/g, while that of As(III) - from 17 to 48 ng/g. As there are no watertight rock formations underneath the dumping site, the polluting substances can be easily washed out by ground waters and carried into the Warta River, which is a main source of water for the city of Poznań.

PL

Niniejsza praca przedstawia wyniki oznaczeń arsenu w profilach gruntów pobranych z wylewiska ługów pokrystalicznych (obecnie w trakcie rekultywacji) na terenie Zakładów Chemicznych w Luboniu koło Poznania W badaniach skoncentrowano się na zawartości dwóch najbardziej toksycznych form arsenu As(lll) i As(V) w środowiskowo dostępnej frakcji wymiennej gruntów. Do ekstrakcji frakcji użyto buforu fosforanowego o pH = 6.0 š 0,2. Analizę wykonywano z zastosowaniem układu technik łączonych HPLC-HG-AAS. Stwierdzono obecność formy As(V) we wszystkich próbkach oraz formy As(l II) w kilku próbkach z różnych głębokości. Stężenie As(V) kształtowało się w przedziale od 91-1228 ng/g, natomiast As(III) od 17^t8 ng/g. Z powodu braku utworów nieprzepuszczalnych pod składowiskiem obecne w gruncie zanieczyszczenia mogą być stosunkowo łatwo wymywane przez wody gruntowe i odprowadzane do pobliskiej rzeki Warty, będącej głównym źródłem wody dla aglomeracji miasta Poznania.

2

Activated carbons for the removal of heavy metal ions: A systematic review of recent literature focused on lead and arsenic ions

100%

Deliyanni E. A. , Kyzas G. Z. , Triantafyllidis K. S. , Matis K. A.

Open Chemistry

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2015

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tom 13

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nr 1

EN

This work is a systematic review of the literature over the past decade of the application of activated carbon (microporous or mesoporous) as adsorbents for the removal of heavy metals, focusing especially on lead (Pb) and arsenic (As) ions from the aqueous phase. Classical examples from our lab are also given. Activated carbon is known to provide a high surface area for adsorption. Generally, surface modification is typically required, such as oxidation, treatment with ammonia or even impregnation with ferric ion, etc. and the adsorbent material may originate from various sources. The pristine materials, after modification and those after batch-wise adsorption, were characterized by available techniques (BET analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analyses, X-ray photoelectron spectroscopy). Adsorption isotherms, thermodynamics and kinetics of the process are also discussed. Selected studies from the literature are examined in comparison with other adsorbents. The role of chemistry in the metals adsorption/removal was investigated.

3

Optimal conditions for the biological removal of arsenic by a novel halophilic archaea in different conditions and its process optimization

100%

Taran M. , Safari M. , Monaza A. , Reza J. Z. , Bakhtiyari S.

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tom Vol. 15, nr 2

7--9

EN

Recently, concerns about arsenic have been increased due to its high acute toxicity to human and serious environmental problems. In this study, the ability of Halorcula sp. IRU1, a novel halophilic archaea isolated from Urmia lake, Iran for arsenic bioaccumulation was investigated and optimized by Taguchi experimental design. The optimum conditions for high arsenic bioaccumulation by Haloarcula sp. IRU1 could be achieved in the presence temperature 40oC, pH 8 and NaAsO2 at 90 mg/L. Under optimum conditions, the microorganism was able to perform their desired function with a 60.89 percent removal of arsenic. In conclusion, Haloarcula sp. IRU1 is resistant to arsenic and removes it in different conditions.

4

Utlenianie As(III) do As(V) jako proces wspomagający usuwanie arsenu z wód

100%

Kociołek-Balawejder E. , Ociński D.

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tom T. 85, nr 8-9

1027-1030

PL

Skuteczność większości technologii usuwania arsenu z wód uwarunkowana jest stopniem jego utlenienia. Związki As(III), bardziej toksyczne i występujące w wodach naturalnych w postaci niezdysocjowanej, są znacznie trudniej usuwalne niż związki As(V) obecne w wodzie w postaci jonów. Często zatem konieczne jest wstępne utlenienie As(III) przed właściwym procesem oczyszczania wody. Dokonano przeglądu metod utleniania As(III) do As(V) obejmujących wykorzystanie utleniaczy homogenicznych, heterogenicznych, a także promieniowania UV i UV–Vis. Wspomniano również o utlenianiu biologicznym jako alternatywie dla technik tradycyjnych.

EN

A review with 41 refs. covering homo and heterogeneous oxidn. of As(III), Mn and Fe oxides as concomitants, photochem. and biol. oxidn. of As(III).

5

Beneficiation of arsenic bearing complex sulphide ore by flotation

100%

Gul A. , Bulut G. , Sirkeci A. A.

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tom Vol. 49, iss. 1

203--212

EN

In this study beneficiation of a sulphide ore from the Gümüşhane-Black Sea Region of Turkey was investigated. Detailed flotation studies were carried out with the ore sample which contained 2.95% Pb, 6.72% Zn and 0.32% Cu. Mineralogical analyses showed that the sample includes pyrite, galena, sphalerite, chalcopyrite, tennantite, cerussite, anglesite and smithsonite. On the other hand, hematite, goethite, limonite, calcite and quartz were determined as gangue minerals. Selective sulphide concentrates with low arsenic content were tried to be produced by froth flotation. Individual concentrates of Pb, Zn and Cu assayed 67.54% Pb, and 61.49% Zn and 23.31% Cu where corresponding recoveries were 73.0% and 77.1% and 38.7%, respectively. Arsenic contents were less than 2000 ppm in the lead and zinc con-centrates. Copper concentrate assayed 5.03% As since the major copper minerals were in tennantite form (copper arsenic sulphide mineral). In flotation tests, non-toxic reagents such as metabisulphite, caustified starch, and activated carbon were used to depress minerals in relevant circuits.

6

Application of fly ash agglomerates in the sorption of arsenic

100%

Polowczyk I. , Bastrzyk A. , Koźlecki T. , Rudnicki P. , Sawiński W. , Sadowski Z. , Sokołowski A.

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nr 2

37-41

EN

The scope of this contribution was to investigate in detail an application of fly ash adsorbent for the removal of arsenite ions from à dilute solution. The experiments have been carried out using fly ash from black coal burning power plant "Siersza" and brown coal burning power plant "Turów" (Poland), which was wetted, then mixed and tumbled in the granulator with a small amount of cement to increase the mechanical strength of agglomerates. The measurements of arsenic adsorption from the aqueous solution were carried out in the flask (with shaking), as well as in the column (with circulation), in order to compare two different methods of contacting waste with adsorbent. The adsorption isotherms of arsenic were determined for granulated material, using the Freundlich model. Kinetics studies indicated that the sorption follows a pseudo-first-order (PFO) model (Lagergren) and the Elovich-type model.

7

Spatial distribution of arsenic in surface sediments of the southern Baltic Sea

100%

Szubska M. , Bełdowski J.

Oceanologia

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2023

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tom Vol. 65 (2)

423--433

EN

Arsenic is a ubiquitous chemical element, occurring naturally worldwide. Yet due to its global cycle, its concentrations in the marine environment are manifold higher than the terrestrial background and may pose harm to biota. This is especially relevant for the Baltic Sea, which is very susceptible to any kind of pollution. Arsenic transported to the sea is adsorbed on iron oxides or precipitating as flocculating particulates and finally bounded in sediments. Therefore, despite the contemporary emission cuts, the existing pollution remains or constantly circulates in marine habitats. The purpose of the research was to recognize the spatial distribution of arsenic in the surface sediments of the southern parts of the Baltic Sea. The number of 483 samples allowed us to prepare reliable interpolation of arsenic contents in surface sediments. Although arsenic concentrations in the Baltic Sea can be considered low, in particular areas the levels are significantly higher. The observed arsenic concentrations distribution pattern could be mostly explained by natural transportation and accumulation bottom-type distribution.

8

Arsenic in Agricultural Soils of Slovakia

88%

Kobza J.

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tom 54

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nr 1

EN

The article presents the current distribution of arsenic in agricultural soils of Slovakia. The current concentration of arsenic (extracted with aqua regia) was measured and evaluated based on 318 monitoring sites of national soil monitoring system in Slovakia. Based on the obtained results, one can state that the average content of arsenic is lower than the valid hygienic limit for arsenic (25 mg.kg-1) for predominated sandy-loamy and loamy soils in Slovakia. Increased values of arsenic were determined only for the Horná – Upper Nitra region (anthropogenic impact) – 24.5 mg.kg-1 and for the Stredný – Central Spiš region (mixed anthrophogenic and geogenic impact) – 129.5 mg.kg-1. These regions belong to the most arsenic-affected regions in Slovakia, where the content of bioavailable forms of arsenic is also increased in the range of 0.013–0.997 mg.kg-1. The hygienic limit for bioavailable arsenic in soils of Slovakia is 0.4 mg.kg-1. Finally, there is a serious risk of arsenic transport from soil into the plants and food chain especially in case of acid soils. A higher risk of As presence seems to be in anthropogenically affected soils.

9

Use of fly ash and fly ash agglomerates for As(III) adsorption from aqueous solution

88%

Ulatowska J. , Polowczyk I. , Sawiński W. , Bastrzyk A. , Koźlecki T. , Sadowski Z.

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nr 1

21-27

EN

The objective of the present study is to assess the efficiency of fly ash and fly ash agglomerates to remove arsenic(III) from aqueous solution. The maximum static uptakes were achieved to be 13.5 and 5.7 mgAs(III)/adsorbent for nonagglomerated material and agglomerated one, respectively. Isotherm studies showed good fit with the Langmuir (fly ash) and the Freundlich (fly ash agglomerates) isotherm models. Kinetic studies indicated that the sorption of arsenic on fly ash and its agglomerates follows the pseudo-second-order (PSO) chemisorption model (R2 = 0.999). Thermodynamic parameters revealed an endothermic nature of As(III) adsorption on such adsorbents. The adsorption results confirmed that fly ash and its agglomerates can be used for As(III) removal from aqueous solutions. Fly ash can adsorb more arsenic(III) than agglomerates, which are easier to use, because this material is less dusty and easier to separate from solution.

10

Behavior of arsenic in hydrometallurgical zinc production and environmental impact

88%

Peltekov A. B. , Boyanov B. S. , Markova T. S.

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nr 4

80-86

EN

The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS). In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5). In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine were studied. The arsenic contamination of soils in the vicinity of nonferrous metals smelter KCM SA, Plovdiv, Bulgaria as a result of zinc and lead productions has been studied.

11

Arsenate removal on the ion exchanger modified with cerium(III) ions

88%

Dudek S. , Kołodyńska D.

Physicochemical Problems of Mineral Processing

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2022

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tom Vol. 58, iss. 2

art. no. 147412

EN

The iron oxide ion exchanger Ferrix A33E was successfully modified with cerium(III) ions to obtain Ferrix A33E-Ce(III) providing much better sorption properties in relation to the As(V) species. The new material has been characterized using a number of techniques including scanning electron microscopy SEM, nitrogen adsorption/desorption isotherms, Fourier transform infrared spectroscopy FTIR and X-ray photoelectron spectroscopy XPS. At optimal pH 6 the main mechanism of arsenate adsorption on A33E-Ce(III) was electrostatic attraction and formation of monodentate and bidentate surface complexes. The process was exothermic and spontaneous. Unlike the unmodified ion exchanger, A33E-Ce(III) could completely remove arsenic from the arsenate solution at a concentration of 50 mg/dm3 in 60 minutes. Furthermore, the maximum sorption capacity for As(V) was determined to be 60.41 mg/g which almost doubled after modification with cerium(III) ions. It is also worth noting that even after three cycles of sorption/desorption A33E-Ce(III) exhibited a higher sorption capacity than unmodified A33E before the arsenate adsorption. It can be concluded that modifying the sorbent with a small amount of cerium(III) ions boosts its sorption properties significantly, improves effectiveness of water purification and reduces the overall operation cost

12

Adsorption behaviour of As(III) onto synthetic iron-based minerals: a comparative study of akaganeite, goethite and magnetite

88%

Ulatowska J.

Physicochemical Problems of Mineral Processing

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2022

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tom Vol. 58, iss. 2

art. no. 144818

EN

The present study compares the adsorption capacity of iron-based minerals in removing As(III) from aqueous solutions. The work contains the results of studies carried out on a laboratory scale. The synthetic material was used in three forms as akaganeite, goethite and magnetite. To characterise the minerals before and after adsorption of As(III), specific surface area, particle size distribution, density, and zeta potential were determined. Additionally, digital and optical micrographs, SEM, and FTIR analyses were performed. In the experimental part, the influence of the main parameters on the adsorption efficiency was investigated (pH, initial concentration, contact time, and amount of adsorbent). Adsorption isotherms were fitted by Freundlich, Langmuir, and DubininRadushkevich models. Pseudo-first-order (PFO), pseudo-second-order (PSO), and intraparticle diffusion (IPD) models were used to fit the kinetics data. Linear regression was used to estimate the parameters of isotherm and kinetic models. FTIR measurements gave helpful information on the synthesised minerals and the As(III) removal process. Results show that As(III) adsorption is related to the iron-based adsorbents, and adsorption efficiency increases in the following order: goethite < magnetite < akaganeite.

13

Flotation of antimony ores with high arsenic content

88%

Özer M.

Physicochemical Problems of Mineral Processing

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2022

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tom Vol. 58, iss. 5

art. no. 152865

EN

Efficient evaluation of antimony ores, which are on the critical raw materials list due to the supply risk by the European Union, is an important necessity. In this context, ore preparation and enrichment processes are very important during the process from ore to metal. Especially for sulfide antimony ores, the most common beneficiation method is flotation. Therefore, antimony ore consisting of stibnite mineral obtained from Tokat-Turkey region was used in this study. Due to the low antimony (5.06%Sb) and the high Arsenic (1.38%As) content, it is an important requirement to increase the Sb content of this ore by flotation, as well as to reduce the As content to certain levels. Stibnite as an antimony mineral and arsenopyrite as arsenic mineral, are minerals that have a sulphurous structure in mineralization and their flotation properties are quite close to each other. Therefore, in this study, it is aimed to selectively separate the bulk concentrate taken from rougher flotation by cleaning steps. A bulk sulfur concentrate with 24.54% Sb and 3.69% As content obtained as a result of the rougher flotation was obtained with a recovery of 98.9%. This product was subjected to 6 stages of cleaning flotation and a concentrate with a content of 63.8% Sb and 0.31% As was produced with an antimony recovery of 83% Sb.

14

Zastosowanie różnych metod szacowania wartości tła pierwiastków w osadach dennych na przykładzie arsenu

88%

Loska K.

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tom Nr 6

23-25

EN

Statistical characteristic of arsenic contents in bottom sludge in Rybnicki reservoir. Distribution of arsenic contents in bottom sludge. Common appearance of arsenic and iron. Summary of background contents and upper limit of arsenic background in bottom sludge, marked by different methods.

15

Speciation Analysis of Arsenic in Copper Electrolyte Baths Using Liquid-liquid Extraction and ICP-OES Method Detection

88%

Stefanov E. , Georgieva S.

Archives of Metallurgy and Materials

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2022

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tom Vol. 67, iss. 2

607--613

EN

The present study describes a method for the determination of As (III) and As (V) in copper electrolytes. The method is based on the separation of As (III) from a copper electrolyte by triple liquid-liquid extraction using a non-polar organic solvent in a medium of 10-12 mol L-1 HCl. The extract contains As (III) and the raffinate-As (V), respectively. As(III) specie can be re-extracted from the organic solvent through the water. Analyzes of the concentration of As in the re-extract and raffinate were performed by ICP-OES spectroscopic method. The average recovery of arsenic by the proposed method is about 99%. Repeatability was estimated with RSD (n = 6). Selectivity and accuracy were proven by the standard addition method. The relative error for restoring the standard addition of As (III) is about 0.3%. The speciation method analysis could be applied for determination of the arsenic species in the analytical quality control of refined copper in copper tanks in the production of copper cathodes.

16

Use of fly ash and fly ash agglomerates for As(III) adsorption from aqueous solution

88%

Ulatowska J. , Polowczyk I. , Sawiński W. , Bastrzyk A. , Koźlecki T. , Sadowski Z.

|

2014

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tom Vol. 16, nr 1

21--27

EN

The objective of the present study is to assess the efficiency of fly ash and fly ash agglomerates to remove arsenic(III) from aqueous solution. The maximum static uptakes were achieved to be 13.5 and 5.7 mgAs(III)/adsorbent for nonagglomerated material and agglomerated one, respectively. Isotherm studies showed good fit with the Langmuir (fly ash) and the Freundlich (fly ash agglomerates) isotherm models. Kinetic studies indicated that the sorption of arsenic on fly ash and its agglomerates follows the pseudo-second-order (PSO) chemisorption model (R2 = 0.999). Thermodynamic parameters revealed an endothermic nature of As(III) adsorption on such adsorbents. The adsorption results confirmed that fly ash and its agglomerates can be used for As(III) removal from aqueous solutions. Fly ash can adsorb more arsenic(III) than agglomerates, which are easier to use, because this material is less dusty and easier to separate from solution.

17

Effect of pyrite type on the electrochemistry of chalcopyrite/pyrite interactions

88%

Forbes E. , Smith L. , Vepsalainen M.

Physicochemical Problems of Mineral Processing

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2018

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tom Vol. 54, iss. 4

1117--1129

EN

Pyrite is the most common sulphide gangue mineral occurring in base metal sulphide ores around the world. Pyrite is known to galvanically interact with valuable minerals such as chalcopyrite, altering their electrochemical and flotation behaviour. Different types of pyrite are known to vary in texture, chemical composition and electrochemical activity. However, the effect that these differences have on the degree of pyrite interaction with chalcopyrite are not well studied. This work examines two distinct types of pyrite from different deposits that have a similar chemical composition, but vary greatly in texture. It investigates the way in which these pyrites interact with chalcopyrite surfaces, affecting both its electrochemical behaviour and floatability. It was found that the Renison pyrite was characterised by a much higher level of surface activity than the Huanzala pyrite. This was attributed to the elevated levels of arsenic within the mineral’s crystalline matrix.

18

Behavior of arsenic in hydrometallurgical zinc production and environmental impact

88%

Peltekov A. B. , Boyanov B. S. , Markova T. S.

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2014

|

tom Vol. 16, nr 4

80--86

EN

The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS). In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5). In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine were studied. The arsenic contamination of soils in the vicinity of nonferrous metals smelter KCM SA, Plovdiv, Bulgaria as a result of zinc and lead productions has been studied.

19

Usuwanie arsenu w postać skorodytu z wybranego materiału arsenonośnego metodą bezciśnieniową skala 1/4 techniczna

75%

Szołomicki Z. , Chmielarz A. , Piwowońska J.

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tom R. 61, nr 11

467--475

PL

W Instytucie Metali Nieżelaznych w Gliwicach opracowano sposób wytrącania skorodytu metodą bezciśnieniową, z użyciem zarówno jonów Fe(III), jak i Fe(II). Przedmiotem badań był jeden z półproduktów arsenonośnych powstających w hutnictwie miedzi. Technologia przerobu materiału arsenonośnego składa się z 4 podstawowych węzłów technologicznych: ługowania materiału arsenonośnego, wytrącania skorodytu, usuwania resztek As i Fe oraz wytrącania Cu, wszystkie połączone z niezbędnymi operacjami rozdziału faz. W artykule zaprezentowano kompleksowe wyniki badań procesu, zmierzającego do przeprowadzenia arsenu zawartego w gąbce miedziowo-arsenowej w postać skorodytu z zastosowaniem jonów Fe(II), wraz ze sposobem zagospodarowania miedzi. Badania wykonano w skali ¼ technicznej na instalacji pilotowej w IMN. Jakość otrzymanego skorodytu była oceniana poprzez pomiar kilku wybranych właściwości fizykochemicznych, takich jak: powierzchnia właściwa ziaren, ich wielkość oraz wyznaczenie podatności na wymywanie arsenu według normy PN-EN 12457-4: 2006, określającej kryteria klasyfikacji odpadu do deponowania na odpowiednim składowisku.

EN

Institute of Non-Ferrous Metals in G/iwice developed a method for precipitation of scomdite by non-pressure method from one of the arsenic in¬termediates generated in copper metallurgy, by application of both Fe(lll) and Fe(ll) ions. Treatment of the arsenic-bearing material consists of four basic technological operations: 1 - leaching of arsenic-bearing material with separation of phases, 2 - precipitation of scomdite with separation of phases, 3 - removal of As and fe residues with separation of phases, and 4 - precipitation of Cu with separation of phases. Paper presents complex results of the studies performed on pilot scale (% of production scale) with application of Fe(ll) ions for utilization of arsenic from copper-arsenic sponge in a form of scomdite with transformation of copper into commercial product. Quality of the produced scomdite was assessed by measurements of several of selected physicochemical properties, such as specific surface of grains, their size and teachability of arsenic according to the PN-EN 72457-4:2006 standard, which determines criteria for classification of the waste for dumping in a relevant site.

20

Wykorzystanie katodowej woltamperometrii adsorpcyjnej do monitoringu arsenu w glebach

75%

Opydo J.

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tom Vol. 9, nr 2-3

285-289

PL

Przeanalizowano warunki oznaczania arsenu w próbkach gleb metodą katodowej woltamperometrii adsorpcyjnej, w technice różnicowej pulsowej, z użyciem wiszącej rtęciowej elektrody kroplowej. Arsen z gleb ekstrahowano mieszaniną HCI + HNO3 (3 : l). Elektrolitem podstawowym był 0,6 mol/dm3 H2SO4 z dodatkiem 0,5 mol/dm3 D-mannitolu, I x 10-6 mol/dm3 Se4+ oraz 4 x 10-4 mol/dm3 CU2+. Opracowaną metodykę wykorzystano do analizy stopnia zanieczyszczenia arsenem gleb pochodzących z okolic Huty Miedzi Głogów.

EN

Conditions of determination of arsenic using cathodic adsorptive stripping voltammetry with differential pulse technique and hanging mercury drop electrode have been analyzed. Arsenic was extracted from soils with HCI + HNO3 mixture (I : 3).0.6 mol/dm3 H2SO4 was supporting electrolyte with addition of O.5 mol/dm3 D-mannitol, I x 10 -6 mol/dm3 Se4+ and 4 x 10 -4 mol/dm3 Cu2+. The method has been applied to study the degree of contamination of soils in the vicinity of Huta Miedzi Głogów Smeltery with arsenic.