scholarly journals Physicochemical characteristics and suitability of curative pastes made of Tunisian clay minerals and thermal waters for use in pelotherapy

2019 ◽  
Vol 22 (2-3) ◽  
pp. 126-131 ◽  
Author(s):  
Thouraya Barhoumi ◽  
Imene Bekri-Abbes ◽  
Ezzeddine Srasra
Keyword(s):  
Clay Minerals ◽  
Physicochemical Characteristics ◽  
Thermal Waters

scholarly journals Low-enthalpy thermal waters within Khoja-Obi-Garm field (Republic of Tajikistan)

2019 ◽  
Vol 98 ◽  
pp. 01011
Author(s):  
Anna Demonova ◽  
Natalia Kharitonova ◽  
Ivan Bragin ◽  
Georgiy Chelnokov ◽  
Vladimir Ivanov
Keyword(s):  
Low Temperature ◽  
Clay Minerals ◽  
Thermal Waters ◽  
Southern Slope ◽  
High Ph ◽  
Subsurface Temperatures

This paper presents data on the composition of the low-enthalpy thermal waters from the unique Khoja-Obi-Garm field located at the central part of the southern slope of the Gissar Range, in the gorge of the Khoja-Obi-Garm River, at an altitude of 1740-1960 meters. In this place, the eponymous SPA-center was built. Groundwaters from springs and boreholes of Khoja-Obi-Garm SPA has temperatures from 57 to 93°C, high pH (up to 8) and low TDS (less than 0.5 g/l). The estimated subsurface temperatures for the same thermal waters vary from 140°C to 156°C and 193-197°C based on the silica and K/Na geothermometer temperatures consequently. These waters belong to Na–SO4–HCO3 type with high content of H2SiO3 (~140 mg/l), F (up to 18 mg/l) and Rn (up to 814 Bq/l). Thermodynamic speciation indicated that these groundwaters are supersaturated with clay minerals and low-temperature zeolites and undersaturated with carbonate and main alumosilicate minerals.

Clay minerals in sediments from thermal waters in Kunashir Island, Kurils

1973 ◽  
Vol 15 (1) ◽  
pp. 89-97 ◽  
Author(s):  
V.A. Volchenkova ◽  
A. V. Zotov ◽  
L.V. Klochkov ◽  
V.A. Frank-Kamenetskiy
Keyword(s):  
Clay Minerals ◽  
Thermal Waters ◽  
Kunashir Island

Sorption of As(V) by some oxyhydroxides and clay minerals. Application to its immobilization in two polluted mining soils

Clay Minerals ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 187-194 ◽  
Author(s):  
A. García- Sanchez ◽  
E. Alvarez-Ayuso ◽  
F. Rodriguez-Martin
Keyword(s):  
Adsorption Capacity ◽  
Clay Minerals ◽  
Arsenic Species ◽  
Physicochemical Characteristics ◽  
Extractable Fraction ◽  
Fe Oxyhydroxides ◽  
Mining Soils ◽  
Remediation Process ◽  
Very High ◽  
Water Extractable

AbstractAmong the arsenic species in the environment, arsenate predominates under oxidizing conditions in soils and waters. The adsorption of As(V) by some natural Fe oxyhydroxides and clay minerals and synthetic Al(OH)3and FeOOH has been studied. The results show a very high As(V) adsorption capacity on both synthetic Al hydroxide (122 mg/g at pH: 5) and Fe oxyhydroxide (76 mg/g at pH 5). This adsorption capacity is pH dependent and shows maximum values at ∼pH 4. The application of these adsorbents to arsenic immobilization in the remediation process of two polluted mining soils with some differences in their physicochemical characteristics has also been studied. The best results were obtained when synthetic Al(OH)3and FeOOH were used; these materials decreased the water-extractable fraction of As by 55–79% for one soil and by nearly 100% for the other soil, the latter with higher pH and Eh values.

INFLUENCE OF CLAY MINERALS ON MICROORGANISMS: III. EFFECT OF PARTICLE SIZE, CATION EXCHANGE CAPACITY, AND SURFACE AREA ON BACTERIA

1966 ◽  
Vol 12 (6) ◽  
pp. 1235-1246 ◽  
Author(s):  
G. Stotzky
Keyword(s):  
Particle Size ◽  
Cation Exchange ◽  
Surface Area ◽  
Clay Minerals ◽  
Cation Exchange Capacity ◽  
Physicochemical Characteristics ◽  
Exchange Capacity ◽  
Bacterial Respiration ◽  
Effect Of Particle Size ◽  
Stimulation Of

The stimulation of bacterial respiration by clay minerals was related to certain physicochemical characteristics of clays. Respiration increased with an increase in the cation exchange capacity and surface area of the particles. The importance of surface area, however, could not be unequivocally established, as some of the methods used to determine this characteristic on certain clay species were questionable. Particle size did not appear to be a critical characteristic. The implications of the cation exchange capacity of clay minerals in the activity, ecology, and population dynamics of microorganisms in nature are discussed.

scholarly journals CONTRIBUIÇÕES NATURAIS E ANTROPOGÊNICAS PARA A CONCENTRAÇÃO E DISTRIBUIÇÃO DE METAIS PESADOS EM SEDIMENTO DE CORRENTE NO RIO DO FORMOSO, MUNICÍPIO DE BURITIZEIRO – MG

2013 ◽  
Author(s):  
Hernando Baggio ◽  
Adolf Heinrich Horn
Keyword(s):  
Heavy Metals ◽  
Clay Minerals ◽  
Physicochemical Characteristics ◽  
Stream Sediments ◽  
Icp Oes ◽  
Organic Residues ◽  
Commercial Agriculture ◽  
Sediment Samples ◽  
X Ray ◽  
Mineral Characterization

O Rio do Formoso é um importante tributário do Rio São Francisco no noroeste do estado de Minas Gerais.Sua bacia encontra-se inserida no Bioma Cerrado, suas águas drenam imensos latifúndios com forte tendênciaagropecuária, influenciando diretamente nas características fisico-químicas e químicas da água superficiale do sedimento de corrente. Foram coletadas 11 amostras de sedimentos, nos quais foram determinadas asconcentrações de Cu, Cd, Cr, Ni, Pb, Zn por ICP-OES, com, extração parcial ácida. Os resultados foramcomparados à resolução CONAMA 344/2004. A caracterização mineral foi obtida por difratometria deRaios-X, e a composição geoquímica dos litotipos foi determinada por ICP-OES. Os teores totais dos metaisCd e Cr nos sedimentos violaram os valores de referência estabelecidos pela Resolução CONAMA 344/2004.A disponibilidade desses metais nos sedimentos é resultado direto dos resíduos metalorgânicos gerados pelaagricultura comercial. A assinatura geoquímica para o elemento cromo presente no sedimento, confirma acontribuição natural geológica. O mineral predominante é o quartzo, a presença de minerais de argila, sugere uma maior ou menor troca de elementos do sedimento para a coluna de água.ABSTRACT: The Formoso River is an important tributary of the São Francisco River in the northwest of Minas GeraisState. Its basin is inserted in the Cerrado Biome, where its waters drain large agropecuary landed estates,what directly influences the physicochemical characteristics of superficial waters and stream sediments. TheCu, Cd, Cr, Ni, Pb and Zn parameters were analyzed in 11 sediment samples by using the chemical partialacid extraction technique and ICP-OES reading, and the results were compared to the CONAMA resolution344/2004. Mineral characterization was accomplished by X-Ray diffractometry and geochemical lithotypesanalysis was made by ICP-OES. It revealed that the levels of Cd and Cr are above the levels recommendedby the resolution CONAMA 344/2004. The presence of these metals in sediments results directly of themetal-organic residues generated by commercial agriculture. The geochemistry signature for the Cr elementpresent in the sediment confirms the geological natural contribution. Quartz is the predominant mineral;the presence of clay minerals suggests a greater or minor interchange of elements from the sediment to thewater column.Key words: Heavy metals, stream sediments, natural, anthropogenic, orienting values.

Physicochemical characteristics for adsorption of MTBE and cadmium on clay minerals

2009 ◽  
Vol 59 (3) ◽  
pp. 537-545 ◽  
Author(s):  
Joo-Hyun Sim ◽  
Hyung-Joon Seo ◽  
Chang-Gyun Kim
Keyword(s):  
Clay Minerals ◽  
Physicochemical Characteristics

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Colloidal systems in soils

1994 ◽  
Vol 52 ◽  
pp. 64-65
Author(s):  
J. Thieme ◽  
J. Niemeyer ◽  
P. Guttman
Keyword(s):  
Clay Minerals ◽  
Polymeric Materials ◽  
Spatial Arrangement ◽  
High Specific Surface Area ◽  
Turnover Rates ◽  
Colloidal Systems ◽  
Chemical Conditions ◽  
Aggregation Phenomena ◽  
Iron And Manganese ◽  
Soil Colloids

In soil science the fraction of colloids in soils is understood as particles with diameters smaller than 2μm. Clay minerals, aquoxides of iron and manganese, humic substances, and other polymeric materials are found in this fraction. The spatial arrangement (microstructure) is controlled by the substantial structure of the colloids, by the chemical composition of the soil solution, and by thesoil biota. This microstructure determines among other things the diffusive mass flow within the soils and as a result the availability of substances for chemical and microbiological reactions. The turnover of nutrients, the adsorption of toxicants and the weathering of soil clay minerals are examples of these surface mediated reactions. Due to their high specific surface area, the soil colloids are the most reactive species in this respect. Under the chemical conditions in soils, these minerals are associated in larger aggregates. The accessibility of reactive sites for these reactions on the surface of the colloids is reduced by this aggregation. To determine the turnover rates of chemicals within these aggregates it is highly desirable to visualize directly these aggregation phenomena.

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