Fractionation of trace elements in some non-agricultural Australian soils

Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1389 ◽  
Author(s):  
J. Li ◽  
A. W. Rate ◽  
R. J. Gilkes
Keyword(s):  
Trace Elements ◽  
Small Proportion ◽  
Residual Fraction ◽  
Fe Oxide ◽  
Fe Oxides ◽  
Weathered Soils ◽  
Highly Weathered Soils

The fractionation of Ag, Ba, Co, Cr, Cu, Ni, Pb, V, and Zn in highly weathered soils was investigated using 5 operationally defined fractions: exchangeable, organic, amorphous Fe oxides, crystalline Fe oxides, and residual fraction. Crystalline Fe oxide and residual phases were the dominant hosts of Ag in the original soils, but for soils to which soluble Ag was added, much Ag was in the crystalline Fe oxide fractions and only a relatively small proportion of Ag was in the residual fraction. Crystalline Fe oxides and the residual fraction were also the major hosts to Co, Cr, Cu, Ni, Pb, V, and Zn.

scholarly journals Association of trace elements and dissolution rates of soil iron oxides

Soil Research ◽  
2014 ◽  
Vol 52 (1) ◽  
pp. 1 ◽  
Author(s):  
D. Ketrot ◽  
A. Suddhiprakarn ◽  
I. Kheoruenromne ◽  
B. Singh
Keyword(s):  
Trace Elements ◽  
Dissolution Rate ◽  
Significant Proportion ◽  
Dissolution Kinetics ◽  
Major And Trace Elements ◽  
Cube Root ◽  
Fe Oxide ◽  
Fe Oxides ◽  
Batch Dissolution ◽  
Dissolution Behaviour

In this study, nine Oxisols and five Ultisols from Thailand were used to determine the association of major and trace elements with iron (Fe) oxides. The Fe oxides were concentrated and the association of elements (Al, Ca, Cu, Cr, Mg, Mn, Ni, Pb, P, Si, V, Ti, Zn) with Fe was evaluated using batch dissolution in 1 m HCl at 20°C. The dissolution behaviour of Fe oxide concentrates was determined using batch dissolution and flow-through reactors. In addition to Fe, both Al and Ti were present in significant amounts in the Fe oxide concentrates. Manganese was the most abundant trace element, and Cu, Zn, Pb and As concentrations were <250 mg kg–1 in most samples. The dissolution behaviour of Fe-oxide concentrates indicated that Al, Cr and V were mostly substituted for Fe3+ in the structure of goethite and hematite. A significant proportion of Mn, Ni, Co, Pb and Si was also present within the structure of these minerals. Some Mg, Cu, Zn, Ti and Ca was also associated with Fe oxides. The dissolution kinetics of Fe oxide concentrates was well described by three models, i.e. the cube root law, Avrami–Erofejev equation and Kabai equation, with the dissolution rate constants (103k) corresponding to the three models ranging from 0.44 to 6.11 h–1, from 1.01 to 4.40 h–1 and from 0.03 to 4.12 h–1, respectively. The k constants of Fe oxide concentrates in this study were significantly and negatively correlated with the mean crystal dimension derived from [110] and [104] of hematite, the dominant mineral in most samples. The steady-state dissolution rate of a soil Fe-oxide concentrate (sample Kk) was substantially higher than for synthetic goethite under highly acidic conditions; this is possibly due to the greater specific surface area of sample Kk than the synthetic goethite.

scholarly journals Geochemical Composition of the Lomé Lagoon Sediments, Togo: Seasonal and Spatial Variations of Major, Trace and Rare Earth Element Concentrations

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3026
Author(s):  
Tchaa Esso-Essinam Badassan ◽  
Akouvi Massan Duanyawo Avumadi ◽  
Kamilou Ouro-Sama ◽  
Kissao Gnandi ◽  
Séverine Jean-Dupuy ◽  
...  
Keyword(s):  
Trace Elements ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Residual Fraction ◽  
West Lake ◽  
Fe Oxides ◽  
East Lake ◽  
Al And Fe Oxides ◽  
Total Concentrations

The concentrations of major, trace (TE), and rare earth (REE) elements and their seasonal and spatial distribution were studied on the fine fraction (<63 µm) of the sediments of the Lomé lagoons (West Lake, East Lake, and Lake Bè). The sediments were collected on a total of nine sampling sites (three per Lake) during two campaigns (dry season and rainy season). The quality of the sediments was assessed on the basis of the enrichment factor (EF) and the labile or non-residual fraction (NRF) in relation to the values recommended for the quality of the sediments (Sediment Quality Guidelines, SQG). The distribution of rare earth elements shows enrichments in light rare earths superior to those of heavy rare earth elements during any season. Positive Ce anomalies are less noticeable and less variable between seasons than Eu anomalies. La/Yb ratios are positively correlated with the percentage of Al and Fe oxides and with the percentage of fine fractions. The main bearing phases of rare earth elements are, therefore, Al and Fe oxides and the finest fractions of the sediments. The concentrations of trace elements vary little, according to the seasons, but show strong variations from one element to another. The degrees of enrichment obtained are moderate for Bi, Cr, Ga, Mo, Pb, Sn, and Zn (1.5 < EF < 5) to significant for As, Cd, and Sb (5 < EF < 20) for all sites of Lake Bè. For the sites of West Lake, the degrees of enrichment obtained are moderate for As, Cd, Cu, Mo, and Pb (1.5 < EF < 5) to a significance for As, Bi, Cd, Pb, Sb, Sn, and Zn (5 < EF < 20). Only the East Lake sites show high degrees of enrichment for elements such as Sb and Sn (20 < EF < 40). Trace elements (TE) such as As, Cd, Cu, and Ni have total concentrations within the range of variation of the SQG concentrations (particularly Probable Effect Level (PEL) and Effect Range Median (ERM)), whereas Cr, Pb, and Zn total concentrations are higher. The ranking of priority sites with respect to the sediment contamination is determined according to ERM and PEL quotients in relation to the probability of toxicity for benthic organisms. For almost all the sites, the priority is lowest to medium-low with regard to As, Cd, and Cu and medium-high (Cr and Ni) to highest (Pb and Zn), particularly for the East and West Lakes. Moreover, the NRF can represent significant percentages of the total TE concentrations: 5% to 15% for As, Bi, Ni, V, Mo, and Sc, 15% to 25% for Co, Cu, and Sr, 25% to 40% for Pb and Zn and, lastly, 47% to 55% for Cd.

scholarly journals Copper availability as related to soil copper fractions in oxisols under liming

2003 ◽  
Vol 60 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Clístenes Williams Araújo do Nascimento ◽  
Renildes Lúcio Ferreira Fontes ◽  
Adilson César Fortes Dias Melicio
Keyword(s):  
Organic Matter ◽  
Atomic Absorption Spectrophotometry ◽  
Soil Samples ◽  
Residual Fraction ◽  
Soil Extracts ◽  
Fe Oxide ◽  
Cu Content ◽  
Mn Oxide ◽  
Copper Availability ◽  
Organic Matter Fractions

The knowledge of the chemical forms of copper in soils and the relationships of these forms with soil copper availability are important for predicting the copper behavior in the soil-plant system. The present work studies the influence of liming on the available contents of copper as well as on the forms of copper fractions in six types of Oxisols. Soil samples, with and without liming, received copper at rates of 0.0, 20.0 and 40.0 mg dm-3 and remained incubated for 30 days. Then, available copper was extracted with Mehlich-1, Mehlich-3, DTPA and EDTA solutions, and analyzed by atomic absorption spectrophotometry. Additionally, soil samples were extracted in a sequential procedure to determine Cu in fractions of soil, as follows: exchangeable-Cu fraction, organic matter-Cu fraction, Mn oxide-Cu fraction, amorphous Fe oxide-Cu fraction, crystalline Fe oxide-Cu fraction, residual-Cu fraction, and the total Cu content in the soil. Soil samples to which Cu was added presented higher Cu retention in the organic matter fraction with a small percentage retained in the exchangeable-Cu fraction. Liming resulted in a decrease of Cu in the exchangeable and organic matter fractions and an increase in the Fe and Mn oxide fractions and in the residual fraction. Without liming, the organic matter fraction presented the highest contribution to Cu content found in the soil extracts obtained with all extractors, except EDTA. For treatments with liming, Cu contents in the organic matter fraction were better correlated to Cu contents in extracts obtained with DTPA and Mehlich-3.

scholarly journals Electrochemical attributes and availability of nutrients, toxic elements, and heavy metals in tropical soils

2006 ◽  
Vol 63 (6) ◽  
pp. 589-608 ◽  
Author(s):  
Mauricio Paulo Ferreira Fontes ◽  
Luís Reynaldo Ferracciú Alleoni
Keyword(s):  
Heavy Metals ◽  
Electrochemical Properties ◽  
Toxic Elements ◽  
Chemical Speciation ◽  
Surface Complexation ◽  
Tropical Soils ◽  
Metal Availability ◽  
Ionic Exchange ◽  
Weathered Soils ◽  
Highly Weathered Soils

Electrochemical properties of soils are very important for the understanding of the physico-chemical phenomena which affect soil fertility and the availability of nutrients for plants. This review highlights the electrochemical properties of tropical soils, the behavior and the availability of nutrients, toxic elements and heavy metals in the soil, especially for soils with predominant variable charge minerals. Availability of the elements is related to ionic exchange, solution speciation, and electrostatic and specific adsorptive soil properties. Empirical and surface complexation models are briefly described, and some results of their application in tropical soils are presented. A better understanding of the role of the double diffuse layer of charges and CEC on nutrient cation availability for highly weathered soils is required, as well as a solid comprehension of surface complexation models, in order to improve the knowledge regarding the behavior of anions in soils. More studies have to be conducted to generate results that enable the use of chemical speciation concepts and calculation of several constants used in surface complexation models, especially for highly weathered soils from the humid tropics. There has to be a continuing development and use of computer softwares that have already incorporated the concepts of chemical speciation and adsorption models in the study of nutrients, toxic elements and heavy metal availability in the soil-plant system.

scholarly journals Iron Oxide Contents in Relation to the Colour of Asnawa Soils

2017 ◽  
Vol 1 (1) ◽  
pp. 89-94
Author(s):  
Sherwan Kafoor
Keyword(s):  
Iron Oxide ◽  
Soil Properties ◽  
Iron Oxides ◽  
Soil Samples ◽  
Visual Methods ◽  
Colour Intensity ◽  
Fe Oxide ◽  
Fe Oxides ◽  
New Formula

Asnawa soils contain high amounts of iron oxides. These minerals apply much influence on different soil properties, of which the most observable is colour. The objective of this study was to conclude if colour of soils measured by visual methods can be parameterized to quantify soil Fe oxides. The examined area was divided to three zones (zone A, zone B and zone C) according to their colour intensity. Forty soil samples were examined for their colour and iron oxide contents. Their colour were ranged between 5YR (H) 2.5 (V/C) to 5YR (H) 5/8 (V/C). The average values of free Fe oxide in the soils of the three zones were 52.1%, 36.8% and 15.9% respectively. A new formula was derived to measure colour intensity. A highly significant correlation was found between colour intensity and concentrations of Fe oxides in the examined soils.

Pseudomorphous transformation of goethite needles into hematite in sediments of the Triassic Skagerrak Formation, Denmark

Clay Minerals ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 657-660 ◽  
Author(s):  
R. Weibel ◽  
B. Grobety
Keyword(s):  
Red Pigment ◽  
Red Beds ◽  
Fe Oxide ◽  
Fe Oxides

Van Houten (1973), Walker (1976) and Turner (1980) have documented the authigenic origin of red coatings in continental red beds. Pigmentary hematite, ferrihydrite, goethite and clay-associated Fe-oxide crystallites have been suggested as the principal colouring agents of continental red beds (Walker, 1968, 1976; Walker & Honea, 1969; Larson & Walker, 1975; Turner, 1980; Fine, 1986, Besly et al., 1993). The red pigment in most Mesozoic red beds consists of hematite, whereas ferrihydrite and goethite are more common in younger sediments (van Houten, 1973). This has led several authors to the assumption that poorly crystalline Fe-oxides/hydroxides age into hematite (Walker, 1968, 1976; Walker & Honea, 1969; Larson & Walker, 1975; Turner, 1980).

Soil warming effects on tropical forests with highly weathered soils

2019 ◽  
pp. 385-439 ◽  
Author(s):  
Tana E. Wood ◽  
Molly A. Cavaleri ◽  
Christian P. Giardina ◽  
Shafkat Khan ◽  
Jacqueline E. Mohan ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Soil Warming ◽  
Weathered Soils ◽  
Highly Weathered Soils

scholarly journals A carbon-sink in a sacred forest: Biologically-driven calcite formation in highly weathered soils in Northern Togo (West Africa)

CATENA ◽  
2021 ◽  
Vol 198 ◽  
pp. 105027
Author(s):  
Hafeez Ur Rehman ◽  
Rosa M. Poch ◽  
Fabio Scarciglia ◽  
Michele L. Francis
Keyword(s):  
West Africa ◽  
Carbon Sink ◽  
Sacred Forest ◽  
Weathered Soils ◽  
Highly Weathered Soils
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