Temat: speciation - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Influence of Decreasing Supplementation to Transformation of Chemical Forms of Ni, Zn and Cu During CompoInfluence of Decreasing Supplementation to Transformation of Chemical Forms of Ni, Zn and Cu During Composting of Sewage Sludge
Autorzy:: Sidełko, Robert
Janowska, Beata
Leśniańska, Aleksandra
Kraszewska, Katarzyna
Grabowska, Karina
Powiązania:: https://bibliotekanauki.pl/articles/2069914.pdf
Data publikacji:: 2021
Wydawca:: Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:: sewage
composting
heavy metals
speciation
Opis:: This paper pertains to the influence of decreasing supplementation to transformation of chemical forms of Ni. Zn and Cu during composting of sewage sludge. A universally used supplementing material constituting a rich source of organic carbon is straw. Addition of straw to sewage sludge is aimed at increasing C/N proportion up to at least 15 due to the risk of formation of toxic forms of nitrogen, concentration of which in sewage sludge is exceptionally high. We have presented in this paper the results of speciation research of three elements applying Tessier’s sequential extraction. It’s been proven that decreasing of straw share in the composted mixture with sewage sludge down to the level of C/N value below the admissible value, has a beneficial effect on the allocation of tested heavy metals towards the forms that are permanently bound in compost matrix. A systematic increase of organic (IV) and residual (V) fractions share and decrease of mobile forms of heavy metals content in bioavailable fractions i.e. ion-exchange (I) and carbonate (II) has been ascertained.
Źródło:: Rocznik Ochrona Środowiska; 2021, 23; 580--593
1506-218X
Pojawia się w:: Rocznik Ochrona Środowiska
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Comparative Studies on the Codeposition of Antimony and Tin from Acidic Chloride and Sulfate-Chloride Solutions
Autorzy:: Rudnik, E.
Kostępski, M.
Powiązania:: https://bibliotekanauki.pl/articles/352105.pdf
Data publikacji:: 2018
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: antimony
electrolysis
speciation
tin
voltammetry
Opis:: Codeposition of antimony and tin from acidic chloride and chloride-sulfate baths was investigated. The calculations of distribution of species showed domination of neutral SnCl₂ and anionic SbCl₄ ^- complexes in chloride solution, while in the presence of sulfate ions neutral SnSO₄ and cationic SbCl²⁺ complexes were found. Cyclic voltammetry, anodic stripping analysis and potentiostatic measurements showed that antimony deposited favorably and the reaction run under limiting control. Analysis of chronoamperometric curves suggested instantaneous nucleation of the solid phase in the chloride bath, but progressive model was more probable in the presence of sulfate ions.
Źródło:: Archives of Metallurgy and Materials; 2018, 63, 2; 709-717
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Land-use impact on selected forms of arsenic and phosphorus in soils of different functions
Autorzy:: Plak, Andrzej
Bartmiński, Piotr
Dębicki, Ryszard
Powiązania:: https://bibliotekanauki.pl/articles/972901.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:: soil pollution
sequential speciation
environmental quality
Opis:: The aim of the study was to assess the impact of technosols and geomechanically unchanged soils of the Lublin agglomeration on the concentrations of arsenic and phosphorus, and on selected forms of these elements. Arsenic and phosphorus concentrations were determined in the urban soils of Lublin (Poland), and the relationship between their degree of contamination and different types of land use was estimated. The samples collected were subjected to sequential analysis, using ammonium sulphate, acid ammonium phosphate, oxalate buffer (also with ascorbic acid) and aqua regia for arsenic, and ammonium chloride, sodium hydroxide, hydrochloric acid and aqua regia for phosphorus. The influence of the land use forms was observed in the study. The greatest amount of arsenic (19.62 mg kg-1) was found in the industrial soils of Lublin, while the greatest amount of phosphorus (580.4 mg kg-1) was observed in non-anthropogenic soils (mainly due to the natural accumulation processes of this element). Fractions of arsenic and phosphorus obtained during analysis showed strong differentiation. Amorphic and crystalline fractions of arsenic, bound with iron oxides, proved to have the highest share in the total arsenic pool. The same situation was noted for phosphorus.
Źródło:: International Agrophysics; 2017, 31, 4; 525-537
0236-8722
Pojawia się w:: International Agrophysics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Manganese and its speciation in environmental samples using hyphenated techniques: A review
Autorzy:: Jablonska-Czapla, M.
Powiązania:: https://bibliotekanauki.pl/articles/15404.pdf
Data publikacji:: 2015
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:: manganese
speciation
environmental sample
hyphenated technique
Opis:: Manganese is one of the most frequently used materials in industry, hence its elevated levels in the surrounding environment. Manganese is an essential nutrient, important in biochemical reactions of several enzymes; on the other hand, it can cause both acute and chronic diseases (eg. manganism). The importance of manganese in living systems remains poorly explored. Manganese compounds share with certain other elements the property of being essential for life, but certain manganese species and large doses are toxic. Manganese plays an important role in iron metabolism and is required for the brain’s normal function. Chemical speciation is an important subject in the environmental protection as well as in toxicological and analytical research because toxicity, availability and reactivity of trace elements depend on the chemical forms in which they occur. This study deals with effects of manganese and manganese speciation forms on living organisms, particularly in aquatic environments. The review presents manganese speciation methods using sophisticated hyphenated techniques.The hyphenated techniques, in which a separation method is coupled with multi-dimensional detectors, have become a useful alternative. These techniques allow for a qualitative and quantitative analysis of the sample composition, wherein manganese may be present in various speciation forms. The article provides many examples of the hyphenated technique application in manganese speciation analysis.
Źródło:: Journal of Elementology; 2015, 20, 4
1644-2296
Pojawia się w:: Journal of Elementology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

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: 6.

Tytuł:: Copper speciation in different-type soil profiles
Specjacja miedzi w profilach gleb zróżnicowanych typologicznie
Autorzy:: Wojcikowska-Kapusta, A.
Niemczuk, B.
Powiązania:: https://bibliotekanauki.pl/articles/16171.pdf
Data publikacji:: 2009
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:: copper form
copper speciation
Haplic Arenosol
lessive soil
rendzina soil
soil
soil profile
soil type
speciation
Opis:: Determination of the total content of metals in soils does not give enough information about their mobility and potential uptake by plants. The influence of heavy metals on plants depends on the type and form of a metal as well as properties of soil. The aim of the research was to evaluate the influence of soil type (Rendzic Leptosols, Haplic Luvisols, Haplic Arenosols) on the content and speciation of copper in soil profiles. The research was carried out in two physiographical regions: Lublin Upland and Sandomierska Valley. Samples were collected once from individual genetics horizons, in total from 30 typological differentiated soil profiles, made from chalk marl, loess and sands. Speciation analysis of copper was carried out with the use of a three-stage sequential method of fractionation, which can isolate four fractions with BCR: fraction I – forms soluble in water, exchangeable and bounded with calcium carbonate, extractable with CH3COOH; fraction II – forms bound with free Fe and Mn oxides, extractable with NH2OHHCl; fraction III – forms complexed with organic matter, hot extractable with 30% H2O2 and next the mineralization products reextractable with CH3COONH4; fraction IV – residual forms (residue), i.e. the difference between the total content and the sum of three fractions I – III. The speciation analysis indicated that in all the examined soil types, the residual form showed the largest share of copper in its total content, followed by forms bounded with organic matter and, containing the smallest proportion of copper, the soluble, exchangeable and bound with calcium carbonate forms. In rendzinas and lessive soils, the content of fraction IV in the humus horizons was significantly higher than in the parent rock, whereas in Haplic Arenosols the host rock was richer in this copper form than the humus horizons.
Określenie całkowitej zawartości metali w glebie nie daje wystarczających informacji o ich ruchliwości i możliwości pobierania przez rośliny. Oddziaływanie metali ciężkich na rośliny zależy od rodzaju metalu, formy, w jakiej występuje, a także od właściwości gleby. Celem pracy była ocena wpływu typu gleb (rędziny, płowe, rdzawe) na zawartość i specjację miedzi w ich profilach. Badania prowadzono na obszarze obejmującym 2 regiony fizjograficzne: Wyżynę Lubelską i Kotlinę Sandomierską. Próbki pobrano jednorazowo z poszczególnych poziomów genetycznych, w sumie z 30 profili glebowych zróżnicowanych typologicznie, wytworzonych z margli kredowych, lessów i piasków. Analizę specjacyjną miedzi przeprowadzono z wykorzystaniem trzystopniowej metody sekwencyjnego frakcjonowania umożliwiającej wyodrębnienie 4 frakcji metodą BCR: frakcja I – formy rozpuszczalne w wodzie, wymienne i związane z węglanami, ekstrahowane CH3COOH; frakcja II – formy zasocjowane z wolnymi tlenkami Fe i Mn ekstrahowane NH2OHHCl; frakcja III – formy związane z materią organiczną ekstrahowane 30% H2O2 na gorąco i następnie reekstrahowane produkty mineralizacji CH3COONH4; frakcja IV – formy rezydualne (pozostałość), różnica między całkowitą zawartością a sumą trzech frakcji. Analiza specjacyjna wykazała, że we wszystkich typach badanych gleb, forma rezydualna miedzi stanowiła największy udział w jej całkowitej zawartości, następnie formy związane z materią organiczną, a najmniejszy formy rozpuszczalne, wymienne i związane z węglanami. W rędzinach i glebach płowych poziomy próchniczne zawierały istotnie więcej IV frakcji niż skały macierzyste, natomiast w glebach rdzawych skała macierzysta zwierała więcej tej formy miedzi niż poziomy próchniczne.
Źródło:: Journal of Elementology; 2009, 14, 4
1644-2296
Pojawia się w:: Journal of Elementology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Glin w oznaczeniach środowiskowych gleby
Environmental determination of aluminum in soils
Autorzy:: Widłak, M.
Widłak, A.
Powiązania:: https://bibliotekanauki.pl/articles/357421.pdf
Data publikacji:: 2013
Wydawca:: Politechnika Śląska
Tematy:: aluminum
aluminum toxicity
speciation
speciation analysis
soil acidity
glin
toksyczność glinu
specjacja
analiza specjacyjna
kwasowość gleby
Opis:: The paper presents a brief description of terms used in chemistry: "trace analysis", "speciation", "speciation analysis" as well as two types of speciation and areas application of speciation. Were presented forms of aluminum present in the soil solution and the mechanisms of soil acidification and the effects of toxic influence on plants root system.
Przedstawiono krótką charakterystykę pojęć używanych w dziedzinie chemii: „analiza śladowa”; „specjacja”; „analiza specjacyjna” jak również dwa rodzaje specjacji i obszary jej zastosowania. Zostały zaprezentowane formy glinu występujące w roztworze glebowym oraz mechanizmy zakwaszania gleby oraz skutki toksycznego oddziaływania na system korzeniowy roślin.
Źródło:: Archiwum Gospodarki Odpadami i Ochrony Środowiska; 2013, 15, 4; 81-88
1733-4381
Pojawia się w:: Archiwum Gospodarki Odpadami i Ochrony Środowiska
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Speciation of Mercury Contaminant in Public Gold Mine Tailing and its Stabilization Using Sulfur and Sulfide
Autorzy:: Trihadiningrum, Yulinah
Latif, Rezki Amalia
Rachman, Ranno Marlany
Powiązania:: https://bibliotekanauki.pl/articles/123133.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: mercury
gold mine
speciation
sulfide
sulfur
tailing
Opis:: The mercury-containing tailing waste from public gold mines in Indonesia is generally deposited on soil without treatment. This research aimed at determining the amount and composition of mercury species in the tailing, and testing the effect of sulfur and sulfide on mercury stabilization. Samples were collected from a tailing pile at different depths in a public gold mine in Kulon Progo, Indonesia. The samples were characterized according to the mercury concentrations and Toxicity Characteristic Leaching Procedure (TCLP) test. Mercury speciation was carried out using nitrogen gas flow into tailing samples, which were placed in three test tubes. The released mercuric species was entrapped in KCl and KmnO₄ solutions. The mercury stabilization was carried out using sulfur and sodium sulfide. TCLP test was performed to the stabilization products. The mercury concentrations were measured using a mercury analyzer. The results showed that the mercury in the tailings were dominated by elemental Hg^o, the concentrations of which in the tailing piles of 30, 60, and 90 cm depths were 74.7%, 71.6%, and 76.5% respectively. Those of ionic Hg²⁺ form were 25.3%, 28.4%, and 23.5%, respectively. Additions of sulfur powder and sodium sulfide solution produced stable black-colored mercury sulfide. When compared to sulfide, sulfur was more recommended for stabilizing mercury in the tailing waste.
Źródło:: Journal of Ecological Engineering; 2019, 20, 4; 29-34
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: The influence of activity coefficient and equilibrium constant models on the speciation of aqueous solutions of H2SO4–MgSO4–Al2(SO4)3 at 235 and 250 °C
Autorzy:: Dickson, Okechukwu Vincent
Deleau, Thomas
Coquelet, Christophe
Espitalier, Fabienne
Lombart, Julien
Tardy, Antoine
Powiązania:: https://bibliotekanauki.pl/articles/24085644.pdf
Data publikacji:: 2023
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: activity coefficient
equilibrium constant
hydrometallurgy
speciation
thermodynamics
Opis:: Supersaturation occurs in many industrial applications promoting reactive crystallisation between the reactants to form solutes. These solutes accumulate during precipitation, leading to the formation of scales on the inner walls of the reactor and particularly around the stirrer, causing modifications in the hydrodynamics. This encrustation is responsible for process shutdowns in continuous crystallisation processes. Supersaturation control is essential for industrial processes aimed at controlling or inhibiting the formation of these solids. Knowledge of mineral solubility and chemical speciation is required to account for the composition of the complexes in the system in their various solid or aqueous forms. This speciation is obtained by considering the thermodynamic equilibrium constants of the dissociation/complexation reactions involved in the system, the pressure, and the activity coefficients of the chemical species in their molecular or electrolyte form. From these thermodynamic quantities and the state of the system, we can predict the direction of the reaction. This study highlights the risk of the lack of experimental information on equilibrium constants at high temperatures and moderate pressures. Our goal is to evaluate the accuracy of existing models classically used to predict the equilibrium constant in such very hard conditions encountered in hydrometallurgical processes. Furthermore, we demonstrate the influences of equilibrium constants estimation and activity coefficient models on the speciation of H2SO4–Al2(SO4)3–MgSO4 systems, forming hydronium alunite and kieserite in the laterite liquor of hydrometallurgical processes.
Źródło:: Physicochemical Problems of Mineral Processing; 2023, 59, 5; art. no. 167497
1643-1049
2084-4735
Pojawia się w:: Physicochemical Problems of Mineral Processing
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Content of Heavy Metals and Their Fractions in Organic Soils of Podlasie
Autorzy:: Wiater, Józefa
Powiązania:: https://bibliotekanauki.pl/articles/124491.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: heavy metal
organic soils
speciation of heavy metals
Opis:: The purpose of this study was to determine the total content of cadmium, lead, nickel, copper, zinc and their fractions in organic soils of Podlasie used as permanent grassland. The research material were samples taken from 30 soils of the Podlasie province in 2011-2013. The samples were taken from the determined layer to depth of 0-30 cm. Basic physicochemical properties were determined in the taken soil samples: organic carbon content, pH in 1 M KCl potentiometrically. The total content of metals after mineralization in aqua regia was determined, and cadmium fractions were determined with a modified BCR method. The measurements were conducted by means of atomic absorption spectroscopy with electrothermal atomization using Varian AA-100 spectrometer. It was found that only 2 soils can be included in the soils with first pollution degree due to the cadmium content. The content of other metals was at geochemical background level. The distribution of investigated metals in the fractions in studied organic soils was different comparing to mineral soils. Most of the analyzed elements were present in the fraction associated with organic substance, which limited their mobility, as evidenced by their low share in the available and potentially available fraction. The proportion of metals in the residual fraction was low, which is typical for organic soils. The share of studied metals in particular fractions varied depending on the sampling date, which may be related to the climatic conditions course in the study period and the treatments performed on these soils.
Źródło:: Journal of Ecological Engineering; 2019, 20, 3; 179-184
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Speciation analysis of phosphorus in bottom sediments - comparison of two methods
Analiza specjacyjna fosforu w osadach dennych - porownanie dwoch metod
Autorzy:: Siwek, H
Powiązania:: https://bibliotekanauki.pl/articles/13856.pdf
Data publikacji:: 2010
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:: speciation analysis
phosphorus
bottom sediment
comparison
method
fractionation
Opis:: The purpose of this paper was to compare two methods of fractionation of reactive phosphorus forms (RP) in bottom sediments of polymictic water reservoirs located in rural areas. As a criterion for estimation, quantities RP extracted in analyzed fractions versus the general content of Al, Fe and Ca were used. The sediments were collected in springtime, from rural areas with different land use in the drainage basin (arable fields, uncultivated land, farmyards). The sediments were collected with a KC-Denmark core sampler for bottom sediments, which makes it possible to collect samples leaving the upper structure of 6 cm in thickness intact. After mineralization, each sample was analyzed for the general phosphorus content and a speciation analysis was performed by two methods. With the first method (M1), the RP bonded to Al (Al_RP), Fe (Fe_RP) and Ca (Ca_RP) was determined. The second method (M2) was applied to determine fractions of reactive phosphorus released from the sediments under reduced conditions, mainly from bonds with iron and manganese (BD_RP), adsorbed on aluminium oxides mainly AL2O3 and other surfaces (NaOH_RP) and apatite phosphorus and bonds with carbonates. In almost all the sediments, most RP was determined in the phosphorus fractions with Ca extracted with acid solution. For the fractions obtained via the M1 method, more of the general RP, as well as phosphorus bonded to calcium and iron was found than for fractions obtained with the M2 method, and the differences might be attributed to translocation of phosphorus from organic to inorganic compounds during fractioning. The fraction of reactive phosphorus determined with the M1 method is correlated more strongly with the general content of the metal in the sediments than reactive phosphorus fractions determined with the M2 method. The strong correlation between the content of iron and the fraction of BD_RP in mineral sediments shows that it can be an indicator of the sensitivity of sediment to changes in the redox potential.
Celem pracy było porównanie dwóch metod frakcjonowania reaktywnych form fosforu (RP) w osadach dennych polimiktycznych zbiorników wodnych zlokalizowanych na terenach wiejskich. Jako kryterium oceny przyjęto ilość RP wyekstrahowanego w badanych frakcjach w odniesieniu do zawartości ogólnej Al, Fe i Ca. Osady do badań pobrano w sezonie wiosennym, z sześciu oczek wodnych zlokalizowanych na terenach wiejskich o różnym sposobie zagospodarowania zlewni (pola uprawne, odłóg, gospodarstwa rolne). Osady pobierano próbnikiem rdzeniowym osadu dennego KC-Denmark, który umożliwia pobór prób z nienaruszoną strukturą wierzchnią warstwy osadów o grubości 6 cm. W każdym osadzie oznaczono, po mineralizacji, ogólną zawartość fosforu (TP), Fe, Ca, Al oraz przeprowadzono analizę specjacyjną fosforu dwoma metodami. Metodą 1 (M1) oznaczono reaktywny fosfor (RP) związany z: Al (Al_RP), Fe (Fe_RP) i Ca (Ca_RP). Metodą 2 (M2) oznaczono frakcje reaktywnego fosforu uwalnianego z osadów w warunkach zredukowanych głównie z połączeń z tlenkami żelaza i manganu (BD_RP), zaadsorbowanego na tlenkach metali głównie na A2O3 i innych powierzchniach (NaOH_RP), fosfor apatytowy i związany z węglanami (HCl_RP). Prawie we wszystkich osadach najwięcej RP oznaczono we frakcjach fosforu związanego z Ca ekstrahowanego roztworem kwasu. We frakcjach otrzymanych metodą M1 oznaczono większe ilości ogólnego RP oraz fosforu związanego z wapniem i z żelazem niż w metodzie M2, a powstałe różnice mogą wynikać z przemieszczania się fosforu ze związków organicznych do nieorganicznych w trakcie frakcjonowania. Frakcje fosforu reaktywnego oznaczonego metodą M1 są silniej skorelowane z ogólną zawartością tych metali w osadzie niż frakcje fosforu reaktywnego oznaczonego metodą M2. Silna korelacja między zawartością żelaza i frakcji BD_RP w osadach mineralnych wskazuje, że może ona być wskaźnikiem wrażliwości osadu na zmianę potencjału redoks.
Źródło:: Journal of Elementology; 2010, 15, 1; 161-170
1644-2296
Pojawia się w:: Journal of Elementology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Mercury fluxes through the sediment water interface and bioavailability of mercury in Southern Baltic Sea sediments
Autorzy:: Beldowski, J.
Miotk, M.
Pempkowiak, J.
Powiązania:: https://bibliotekanauki.pl/articles/49177.pdf
Data publikacji:: 2009
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: speciation
sediment
remobilization
Baltic Sea
bioavailability
mercury
toxic metal
Opis:: Sediment cores collected in several areas of the southern Baltic were analysed for total mercury (HgTOT) and five operationally defined mercury fractions: HgA – contained in pore waters, HgF – bound to fulvic acids, HgH – bound to humic acids, HgS – bound to sulphide, and HgR – residual. An effort was made to quantify mercury fluxes at the sediment/water interface in the study area. Net mercury input, calculated on the basis of sedimentation rate and concentration in the uppermost sediments, ranged from 1 to 5.5 ng cm−2 year−1. Mercury remobilisation from sediments due to diffusion and resuspension was calculated from the proportion of labile mercury and the velocity of near-bottom currents. The results showed that the return soluble and particulate fluxes of mercury from the sediments to the water column constitute a substantial proportion of the input (20–50%), and are slightly higher than those found in pristine areas, although they are less than the values recorded in areas with a history of mercury contamination. In addition, an index was developed to assess the methylation potential of mercury in sediments. Mercury contained in pore waters, and mercury bound to fulvic and humic acids together with Loss on Ignition were used to calculate the semiquantitative methylation potential (Pm). Despite the simplicity of this approach, Pm correlates well with methyl mercury in fish from the study area.
Źródło:: Oceanologia; 2009, 51, 2; 263-285
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Speciation Analysis of Arsenic in Copper Electrolyte Baths Using Liquid-liquid Extraction and ICP-OES Method Detection
Autorzy:: Stefanov, Eduard
Georgieva, Stela
Powiązania:: https://bibliotekanauki.pl/articles/2106573.pdf
Data publikacji:: 2022
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: arsenic
speciation analysis
copper electrolyte
iCP-OES method
extraction
Opis:: 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.
Źródło:: Archives of Metallurgy and Materials; 2022, 67, 2; 607--613
1733-3490
Pojawia się w:: Archives of Metallurgy and Materials
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Neurological and neurophysiological examinations of workers exposed to arsenic levels exceeding hygiene standards
Autorzy:: Sińczuk-Walczak, Halina
Janasik, Beata M.
Trzcinka-Ochocka, Małgorzata
Stanisławska, Magdalena
Szymczak, Maria
Hałatek, Tadeusz
Walusiak-Skorupa, Jolanta
Powiązania:: https://bibliotekanauki.pl/articles/2179016.pdf
Data publikacji:: 2014-12-01
Wydawca:: Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:: occupational exposure
arsenic speciation
nervous system
neuropathy
neurophysiological test
Opis:: Objectives: The assessment of the neurotoxic effect of arsenic (As) and its inorganic compounds is still the subject of interest due to a growing As application in a large array of technologies and the need to constantly verify the principles of prevention and technological parameters. The aim of this study was to determine the status of the nervous system (NS) in workers exposed to As at concentrations exceeding hygiene standards (Threshold Limit Values (TLV) – 10 μg/m³, Biological Exposure Index (BEI) – 35 μg/l) and to analyze the relationship between the NS functional state, species of As in urine and As levels in the workplace air. Material and Methods: The study group comprised 21 men (mean age: 47.43±7.59) employed in a copper smelting factory (mean duration of employment: 22.29±11.09). The control group comprised 16 men, matched by age and work shifts. Arsenic levels in the workplace air (As-A) ranged from 0.7 to 92.3 μg/m³; (M = 25.18±28.83). The concentration of total arsenic in urine (Astot-U) ranged from 17.35 to 434.68 μg/l (M = 86.82±86.6). Results: Syndrome of peripheral nervous system (PNS) was manifested by extremity fatigue (28.6%), extremity pain (33.3%) and paresthesia in the lower extremities (33.3%), as well as by neuropathy-type mini-symptoms (23.8%). Electroneurographic (ENeG) tests of peroneal nerves showed significantly decreased response amplitude with normal values of motor conduction velocity (MCV). Stimulation of sural nerves revealed a significantly slowed sensory conduction velocity (SCV) and decreased sensory potential amplitude. Neurophysiological parameters and the results of biological and environmental monitoring showed a relationship between $\text{As}^\text{tot}$, $\text{As}^\text{III}$ (trivalent arsenic), the sum of iAs ($\text{As}^\text{III}+\text{As}^\text{V}$ (pentavalent arsenic))+MMA (monomethylarsonic acid) concentration in urine and As levels in the air. Conclusions: The results of the study demonstrate that occupational exposure to inorganic arsenic levels exceeding hygiene standards (TLV, BEI) generates disorders typical of peripheral neuropathy.
Źródło:: International Journal of Occupational Medicine and Environmental Health; 2014, 27, 6; 1013-1025
1232-1087
1896-494X
Pojawia się w:: International Journal of Occupational Medicine and Environmental Health
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Speciation of phosphorus in wastewater sediments from selected wastewater treatment plant
Specjacja fosforu w osadach ściekowych z wybranych oczyszczalni ścieków
Autorzy:: Bezak-Mazur, E.
Stoińska, R.
Powiązania:: https://bibliotekanauki.pl/articles/389674.pdf
Data publikacji:: 2013
Wydawca:: Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:: fosfor mobilny
osady ściekowe
specjacja
mobile phosphorous
wastewater sediments
speciation
Opis:: Celem pracy było scharakteryzowanie osadów ściekowych pochodzących z różnych typów oczyszczalni ścieków komunalnych pod względem występowania form specjacyjnych fosforu. Przeprowadzono Speciation of Phosphorus in Wastewater Sediments... 513 wstępną analizę specjacyjną z wykorzystaniem ekstrakcji sekwencyjnej według Goltermana. Polega ona na wykorzystaniu odczynników chelatowych (Ca-EDTA i Na-EDTA) oraz roztworów NaOH i H2SO4. Pomiar ilości fosforu odbył się metodą spektrofotometryczną zgodnie z obowiązującymi normami. Wykorzystując powyższą metodę, zbadano ilości poszczególnych frakcji fosforu w osadach ściekowych oraz stężenie fosforu ogólnego w ściekach oczyszczonych i surowych. Według Goltermana formą specjacyjną o największej dostępności dla organizmów żywych jest fosfor zaadsorbowany na powierzchni cząstek osadów, czyli tak zwany fosfor mobilny. Wstępne wyniki wskazują, iż znaczny udział fosforu mobilnego w osadach ściekowych występował w tych oczyszczalniach, gdzie stosowano zintegrowane metody oczyszczania ścieków (oczyszczalnie mechaniczno-biologiczno-chemiczne). Uzyskane rezultaty upoważniają do stwierdzenia, że w zależności od warunków fizyczno-chemicznych występujących w poszczególnych typach oczyszczalni ścieków, osady nadmierne charakteryzują się różnymi udziałami formy specjacyjnej fosforu mobilnego, co może wpływać na odzyskiwanie tego pierwiastka z osadów ściekowych.
The aim of this work was to characterize wastewater sediments of various types of wastewater treatment plants in terms of the occurrence of forms of phosphorus speciation. The preliminary analysis of speciation using sequential extraction by Golterman was made. It consists in using chelating reagents (Ca-EDTA and Na-EDTA) as well as NaOH and H2SO4 solutions. The quantitative measurement of phosphorus was carried out using spectrophotometric method according to binding rules. The number of individual fractions of phosphorus in wastewater sediments and the concentration of total phosphorus in treated and raw wastewater were examined. According to Golterman the phosphorus absorbed on the surface of sludge particles, so called mobile phosphorus, is a speciation form that is the most easily accessible for organisms. Preliminary results show that the significant participation of mobile phosphorus in wastewater sediments appeared in these wastewater treatment plants, where integrated methods of the wastewater treatment were applied (wastewater treatment plants mechanical-biological-chemical). The results obtained allow to conclude that, depending on the physico-chemical conditions in the various types of wastewater treatment plants, excess sludge shares have different forms of mobile phosphorus speciation, which may affect the recovery of this element from wastewater sediments.
Źródło:: Ecological Chemistry and Engineering. A; 2013, 20, 4-5; 503-514
1898-6188
2084-4530
Pojawia się w:: Ecological Chemistry and Engineering. A
Dostawca treści:: Biblioteka Nauki

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