scholarly journals Heavy metals «versus» clay minerals in the quaternary sediments of the Cortegaça beach formation (Ovar, Portugal)

1999 ◽  
pp. 19-25
Author(s):  
A. Machado ◽  
A. P. Silva ◽  
Fernando Rocha ◽  
Celso Gomes
Keyword(s):  
Heavy Metals ◽  
Clay Fraction ◽  
Fine Fraction ◽  
Absorption Spectrometry ◽  
Thin Layers ◽  
Beach Sand ◽  
Iron Hydroxides ◽  
X Ray Diffraction ◽  
Sedimentary Sequences ◽  
And Cluster Analysis

The site under study (Cortegaça beach) belongs to the Ovar municipality and is part of an extensiveregion characterized by flat terrains, consisting mainly of old beach and dunar deposits. Coastal erosionhad exposed the so called Cortegaça beach formation showing the following three sedimentary sequences,from the basis to the top: 1) greenish sandy clay; 2) sand layers with marked cross-bedded showing ontop a bioturbated podzol; 3) bioturbated beach sand and dune sand. The main goal of the present paper isthe establishment of relationships between heavy metals nature and content with the mineral composition,particularly of the clay component, of those sediments. The study of the fine fraction (less than 38 mm)of forty samples collected along three profiles has been carried out. X-ray diffraction was used for mineralogicaldeterminations, whereas atomic absorption spectrometry was used for the determination of theheavy metals: Cu, Ni, Co, Zn, Pb, Cd, Mn and Cr. Mineralogical studies made evident a gradual verticalevolution marked by the following main features: 1) dominance of quartz and phyllosilicates in the finefraction associated to discrete amounts of feldspar and other accessory minerals; evaporite mineralsand iron hydroxides are particularly important in some thin layers; 2) general dominance of illite overkaolinite in the clay fraction with oscillations of the illite/kaolinite content. As regards with heavy metalscontent the following facts deserve to be emphasized: 1) Pb and Cu are more concentrated in thesandy layers showing cross-bedded, whenever iron hydroxides are enriched; 2) Zn, Cr and less clearly,Ni, Co and Cd behave differently of Pb and Cu; 3) Mn is clearly enriched at the top of the 3rd sequence.For the typification and hierarchization of the relationships between the mineralogical and the chemicalvariables geostatistical analysis has been carried out using, in particular, both Principal ComponentsAnalysis and Cluster Analysis.

scholarly journals Assessment of Environmental Pollution of Heavy Metals Deposited on the Leaves of Trees in Yazd Bus Terminals

2021 ◽  
Author(s):  
motahareh esfandiari ◽  
Mohammad Ali Hakimzadeh
Keyword(s):  
Heavy Metals ◽  
Spatial Distribution ◽  
Green Space ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Principal Component ◽  
Absorption Spectrometry ◽  
Urban Transport ◽  
Heavy Elements ◽  
And Cluster Analysis

Abstract There is a lack of information about urban transport activity in adding heavy elements to the environment. This research assesses concentration some of heavy elements in the deposited atmospheric dust in Yazd bus terminals. Dust samples were collected from the green space in the bus terminals of urban transportation. Following the digestion by nitric acid, determination of the total metal concentration of cadmium(Cd), cobalt(Co), copper(Cu), nickel(Ni), lead(Pb), zinc(Zn), chromium (Cr), and manganese(Mn) in the dust were performed via Atomic Absorption Spectrometry. The map representing the spatial distribution of metals was plotted and their source was identified using Pearson correlation coefficients, Principal Component Analysis(PCA), and Cluster Analysis(CA). The findings indicated that the mean concentration of heavy metals in the deposited dust on the leaves of the trees was in the following order; Cd < Co < Ni < Pb < Cu < Zn < Cr < Mn. The map representing the spatial distribution of heavy metal concentrations indicated that the abundance of metals in different stations varies according to their location. Two important sources for the concentration of heavy metals in the deposited dust on the leaves were identified. The sources of Co, Cd, Mn, and Ni were anthropogenic and lithogenic, and the sources of Pb, Zn, Cr and Cu were the traffic and industrial activities. The amounts of EF, CF, IPI and, RI Indicators in residential, commercial, green space and environmental uses were estimated at low to extremely high levels of pollution. The findings showed that the growth of industrialization and human activities had caused contamination of the environment by heavy metals emitted into the atmosphere of Yazd.

Study of interactions between rhodamine B and a beidellite-rich clay fraction

Clay Minerals ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 194-202
Author(s):  
Hamida Belhanafi ◽  
Abdellah Bakhti ◽  
Noureddine Benderdouche
Keyword(s):  
Rhodamine B ◽  
Clay Fraction ◽  
Fine Fraction ◽  
Sorption Process ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Order Kinetic Model ◽  
Fine Clay ◽  
Competing Cations ◽  
Pseudo Second Order

AbstractThe interaction between a basic dye, rhodamine B, and a separated fine fraction from natural clay was studied. Chemical analysis, X-ray diffraction and Fourier-transform infrared spectroscopy confirmed the predominance of beidellite in the fine clay fraction. The interaction of rhodamine B with the fine clay fraction showed that sorption was fast and followed a pseudo-second-order kinetic model. The comparison between sorbed rhodamine B amounts as a function of the various experimental parameters such as pH, sorbent mass, dye concentration and the presence of competing ions suggests that: (1) the sorption process is largely pH-dependent; (2) significant competition is observed between the dye and the Ca2+ and Mg2+ ions; (3) the sorption proceeds, principally, by a cation-exchange mechanism; and (4) the sorption capacity of the fine fraction in the presence of competing cations such as Ca2+ is ~0.28 mmol g–1.

Heavy metals in groundwater from the Wolonghu coal mine, northern Anhui Province, China and their hydrological implications

2014 ◽  
Vol 9 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Linhua Sun ◽  
Herong Gui ◽  
Weihua Peng
Keyword(s):  
Heavy Metals ◽  
Coal Mine ◽  
Water Source ◽  
Water Quality Assessment ◽  
Quality Standard ◽  
Anhui Province ◽  
Iron Hydroxides ◽  
Deep Aquifers ◽  
And Cluster Analysis ◽  
Inrush Water

Groundwater is important for either resource usage or safety of coal mining in north China. In this study, concentrations of eight kinds of heavy metals (Pb, Cd, Cu, Ni, Cr, Zn, Fe and Mn) in groundwater from three deep aquifers in the Wolonghu coal mine, northern Anhui Province, China have been analyzed for water quality assessment and water source identification. The results suggest that the groundwater have different concentrations of heavy metals among aquifers, which might be the results of different occurrence forms of heavy metals (e.g. Pb, Cd, Cu and Cr were adsorbed by iron hydroxides) and different kinds of water rock interactions (e.g. Mn and Zn originated from carbonate rocks). In comparison with the groundwater quality standard of China and WHO, most of them cannot be used for drinking directly but must be treated before drinking, especially the Pb, Cd and Fe contents. Moreover, hydraulic connection between aquifers has been identified by plots of factor scores and cluster analysis, which is similar to the results obtained by previous studies. Moreover, discriminant analysis demonstrated that heavy metals can be used for identification the source of inrush water in coal mines.

scholarly journals Efficiency of Pb(II) and Mo(VI) Removal by Kaolinite Impregnated with Zero-Valent Iron Particles

Mineralogia ◽  
2017 ◽  
Vol 48 (1-4) ◽  
pp. 71-86 ◽  
Author(s):  
Karolina Rybka ◽  
Katarzyna Suwała ◽  
Paulina Maziarz ◽  
Jakub Matusik
Keyword(s):  
Heavy Metals ◽  
Fourier Transform ◽  
Zero Valent Iron ◽  
Iron Hydroxides ◽  
Iron Particles ◽  
Sorption Experiment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metals Removal ◽  
Interesting Alternative

Abstract In this work, kaolinite modified with zero-valent iron was synthesized and used as a sorbent for Pb(II) and Mo(VI) removal from aqueous solutions. The obtained material was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The methods revealed successful modification by the Fe0particles precipitation on the surface of well-ordered kaolinite. The sorption experiment results showed a significant increase of sorption capacity in relation to the raw kaolinite. The kaolinite with 25% content of Fe0was found to be the best material for Pb(II) and Mo(VI) removal, resulting in approximately 500 mmol·kg-1and 350 mmol·kg-1sorption, respectively. The possible mechanisms responsible for metals’ removal were identified as reduction by Fe0‘core’ and adsorption on the iron hydroxides ‘shell’. The study indicated that the obtained material is capable of efficient Pb(II) and Mo(VI) removal and may be an interesting alternative to other methods used for heavy metals’ removal.

scholarly journals Provenance and Sedimentary Context of Clay Mineralogy in an Evolving Forearc Basin, Upper Cretaceous-Paleogene and Eocene Mudstones, San Joaquin Valley, California

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Andrew Hurst ◽  
Michael Wilson ◽  
Antonio Grippa ◽  
Lyudmyla Wilson ◽  
Giuseppe Palladino ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Upper Cretaceous ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Bulk Rock ◽  
X Ray Diffraction ◽  
Arc Volcanism ◽  
X Ray ◽  
Magmatic Arc ◽  
Tropical Weathering

Mudstone samples from the Moreno (Upper Cretaceous-Paleocene) and Kreyenhagen (Eocene) formations are analysed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) to determine their mineralogy. Smectite (Reichweite R0) is the predominant phyllosilicate present, 48% to 71.7% bulk rock mineralogy (excluding carbonate cemented and highly bio siliceous samples) and 70% to 98% of the <2 μm clay fraction. Opal CT and less so cristobalite concentrations cause the main deviations from smectite dominance. Opal A is common only in the Upper Kreyenhagen. In the <2 μm fraction, the Moreno Fm is significantly more smectite-rich than the Kreyenhagen Fm. Smectite in the Moreno Fm was derived from the alteration of volcaniclastic debris from contemporaneous rhyolitic-dacitic magmatic arc volcanism. No tuff is preserved. Smectite in the Kreyenhagen Fm was derived from intense sub-tropical weathering of granitoid-dioritic terrane during the hypothermal period in the early to mid-Eocene; the derivation from local volcanism is unlikely. All samples had chemical indices of alteration (CIA) indicative of intense weathering of source terrane. Ferriferous enrichment and the occurrence of locally common kaolinite are contributory evidence for the intensity of weathering. Low concentration (max. 7.5%) of clinoptilolite in the Lower Kreyenhagen is possibly indicative of more open marine conditions than in the Upper Kreyenhagen. There is no evidence of volumetrically significant silicate diagenesis. The main diagenetic mineralisation is restricted to low-temperature silica phase transitions.

scholarly journals Concentration of cadmium and lead in vegetables and fruits

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Rusin ◽  
Joanna Domagalska ◽  
Danuta Rogala ◽  
Mehdi Razzaghi ◽  
Iwona Szymala
Keyword(s):  
Heavy Metals ◽  
Fruits And Vegetables ◽  
Significant Risk ◽  
Absorption Spectrometry ◽  
Food Groups ◽  
Chemical Contamination ◽  
Fresh Frozen ◽  
Processed Products ◽  
Cadmium And Lead ◽  
Vegetables And Fruits

AbstractChemical contamination of foods pose a significant risk to consumers. A source of this risk is due to the consumption of products contaminated with heavy metals such as cadmium (Cd) and lead (Pb). The aim of the study was to research the levels of Cd and Pb contamination of selected species of vegetables and fruits in the form of fresh, frozen, dried and processed products. The goal was to verify which of these food groups was more contaminated with heavy metals. The study covered 370 samples of fruits and vegetables including apples, pears, grapes, raspberries, strawberries, cranberries, as well as beetroots, celeries, carrots and tomatoes. The content of Cd and Pb was determined by atomic absorption spectrometry. Quantitative results were analyzed using statistical models: analysis of variance, outlier analysis, post-hoc multiple comparison Tukey test. The tests showed that the levels of Cd and Pb concentration in samples of fresh, processed, frozen and dried fruits and vegetables varied substantially. The highest concentrations were recorded in dried products. Several fruit and vegetable samples exceeded the maximum permissible concentrations of Cd and Pb. The contamination of these products could be a significant source of consumer exposure to heavy metals when these products are a part of the diet.

scholarly journals An analysis of heavy metals contamination and estimating the daily intakes of vegetables from Uganda

2021 ◽  
Vol 5 ◽  
pp. 239784732098525
Author(s):  
Keneth Iceland Kasozi ◽  
Eric Oloya Otim ◽  
Herbert Izo Ninsiima ◽  
Gerald Zirintunda ◽  
Andrew Tamale ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Daily Intake ◽  
Principal Component ◽  
Absorption Spectrometry ◽  
Cross Sectional Study ◽  
Essential Elements ◽  
World Health ◽  
Cross Sectional ◽  
Health Organization ◽  
Daily Intakes

Background: Environmental contamination with elevated levels of copper (Cu), cobalt (Co), iron (Fe), zinc (Zn), lead (Pb), chromium (Cr6+), cadmium (Cd), and nickel (Ni)—all states of which are found in Uganda—raises health risk to the public. Pb, Cr6+, Cd, and Ni for instance are generally considered nonessential to cellular functions, notwithstanding the importance of the oxidative state of the metals in bioavailability. As such, we aimed in this study (i) to evaluate heavy metal concentrations in four vegetables from a typical open-air market in Uganda, (ii) to assess the safety of consuming these vegetables against the World Health Organization (WHO) recommended limits of heavy metals consumption, and (iii) to formulate a model of estimated daily intake (EDI) among consumers in the country. Methods: This was a cross-sectional study conducted in five georeferenced markets of Bushenyi district in January 2020. Amaranthus, cabbages, scarlet eggplants, and tomatoes were collected from open markets, processed, and analyzed by atomic absorption spectrometry. Modeled EDI, principal component (PCA) and cluster analysis (CA) were conducted to identify relationships in the samples. Results: The levels of essential elements in the four vegetables were found to fall from Co > Cu > Fe > Zn. Those of non-essential metals were significantly higher and followed the pattern Cd > Cr > Pb > Ni. The highest EDI values were those of Cu in scarlet eggplants, Zn in amaranthus, Fe in amaranthus, Co in amaranthus, Pb in cabbages, total Cr in scarlet eggplant, Cd in cabbages and tomatoes, and Ni in cabbages. In comparison to international limits, EDIs for Zn, Cu, Co and Fe were low while Ni in cabbages were high. PCA showed high variations in scarlet eggplant and amaranthus. The study vegetables were found to be related with each other, not according to the location of the markets from where they were obtained, but according to their species by CA. Conclusion: The presence of non-essential elements above WHO limits raises policy challenges for the consumption and marketing of vegetables in the study area. Furthermore, low EDIs of essential elements in the vegetables create demand for nutritious foods to promote healthy communities.

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