Extraction Of Soil Samples Research Articles

A field screening test for the assessment of concentrations and mobility of potentially toxic elements in soils: a case study on urban soils from Rome and Novi Sad.

The increasing demand for environmental pollution control results in the development and use of new procedures for the determination of dangerous chemicals. Simple screening methods, which can be used directly in the field for a preliminary assessment of soil contamination, seem to be extremely advantageous. In our laboratory, we developed and optimized a rapid test for a preliminary evaluation of both the concentration and the mobility of some potentially toxic metals in soils. This screening test consists of a single extraction of the soil sample with a buffer solution, followed by the titration of the extracted solution with dithizone to determine the contents of bi-valent heavy metals (such as Pb, Cu, Zn, and Cd). This screening method was then directly applied in the field during the sampling campaign in the framework of an Italian-Serbian collaborative project, finalized in the study of metal availability in soils. The results obtained in the field with the rapid test were compared with those obtained in the laboratory following the conventional procedure commonly used to evaluate metal bioavailability (diethylenetriaminepentaacetic extraction). Moreover, selected samples were analyzed sequentially in the laboratory using the standardized BCR three-step sequential extraction procedure. The screening test gave results conceptually in good agreement with those obtained via the BCR procedure. These preliminary data show that the proposed screening test is a reliable method for the preliminary rapid evaluation of metal total concentrations and of potential metal mobility in soils, supporting sampling activities directly in the field.

Enhanced Natural Biodegradation of Diesel Fuel Contaminants in Soil by Addition of Whey and Nutrients

The contamination of soils by petroleum hydrocarbons, such as diesel fuel, has since many years been a serious environmental problem. Treatment of contaminated areas is a concern for governments and environmental authorities in several countries and efforts have been done with the purpose to eliminate this problem. Different methods have been tested and today the most common technique involves the excavation and transportation of contaminated soil to special treatment facilities. In earlier studies we have demonstrated the effect of adding organic amendments, such as fermented whey, on the biodegradation of n-alkanes in diesel contaminated soil. Non-fermented sweet whey also proved significantly to enhance the biodegradation of an aromatic substance (phenanthrene) in contaminated soil. The current paper presents the results of an in-situ field test at a former gas station in the north of Sweden. In parallel to the field study, biodegradation profiles were monitored under controlled laboratory conditions by taking soil samples from the contaminated site and spike them with diesel fuel. The experiments were carried out by adding whey and mineral nutrients (NPK) to the test area and to the laboratory samples, and monitor the degradation of hydrocarbons by gas chromatographic analysis of extracted soil samples. Significant effects on the degradation rates were achieved in the laboratory tests. For the in-situ test, however, no such positive effects could be registered.

On-site Determination of Trace Arsenic by Reflection-Absorption Colorimetry of Molybdenum Blue Collected on a Membrane Filter.

An on-site determination method for trace arsenic has been developed by collecting it as molybdenum blue (MB) in the presence of tetradecyldimethylbenzylammonium chloride on a mixed cellulose ester membrane filter and by measuring reflection absorbance (RA) of MB on the filter using a laboratory-made palm-top size reflection-absorbance colorimeter with a red light-emitting diode. The value of RA was proportional to the amount of arsenic up to 0.5 μg with a detection limit of 0.01 μg. The proposed method was successfully applied to soil extract and hot-spring water samples.

Distribution of potentially toxic elements (PTEs) in tailings, soils, and plants around Gol-E-Gohar iron mine, a case study in Iran.

This study investigated the concentration of potentially toxic elements (PTEs) including Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, V, and Zn in 102 soils (in the Near and Far areas of the mine), 7 tailings, and 60 plant samples (shoots and roots of Artemisia sieberi and Zygophylum species) collected at the Gol-E-Gohar iron ore mine in Iran. The elemental concentrations in tailings and soil samples (in Near and Far areas) varied between 7.4 and 35.8mgkg-1 for As (with a mean of 25.39mgkg-1 for tailings), 7.9 and 261.5mgkg-1 (mean 189.83mgkg-1 for tailings) for Co, 17.7 and 885.03mgkg-1 (mean 472.77mgkg-1 for tailings) for Cu, 12,500 and 400,000mgkg-1 (mean 120,642.86mgkg-1 for tailings) for Fe, and 28.1 and 278.1mgkg-1 (mean 150.29mgkg-1 for tailings) for Ni. A number of physicochemical parameters and pollution index for soils were determined around the mine. Sequential extractions of tailings and soil samples indicated that Fe, Cr, and Co were the least mobile and that Mn, Zn, Cu, and As were potentially available for plants uptake. Similar to soil, the concentration of Al, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, and Zn in plant samples decreased with the distance from the mining/processing areas. Data on plants showed that metal concentrations in shoots usually exceeded those in roots and varied significantly between the two investigated species (Artemisia sieberi>Zygophylum). All the reported results suggest that the soil and plants near the iron ore mine are contaminated with PTEs and that they can be potentially dispersed in the environment via aerosol transport and deposition.

Simple Colorimetric Sensor for Trinitrotoluene Testing

A simple operating colorimetric sensor for trinitrotoluene (TNT) determination using a commercial scanner as a captured image was designed. The sensor is based on the chemical reaction between TNT and sodium hydroxide reagent to produce the color change within 96 well plates, which observed finally, recorded using a commercial scanner. The intensity of the color change increased with increase in TNT concentration and could easily quantify the concentration of TNT by digital image analysis using the Image J free software. Under optimum conditions, the sensor provided a linear dynamic range between 0.20 and 1.00 mg mL-1(r = 0.9921) with a limit of detection of 0.10± 0.01 mg mL-1. The relative standard deviation for eight experiments for the sensitivity was 3.8%. When applied for the analysis of TNT in two soil extract samples, the concentrations were found to be non-detectable to 0.26±0.04 mg mL-1. The obtained recovery values (93-95%) were acceptable for soil samples tested.

Soil Salinity and Alkalinity Map Preparation Based on Spatial Analysis of GIS (Case Study: Tabriz Plain)

Better management of agricultural fields is related to valuable information which can derived from soil salinity and alkalinity maps. These maps are considered as one of the most important factors which restrict plant growth as well as decline crops yield. The objective of this research was preparing of soil salinity and alkalinity maps in Tabriz plain over 50,000 hectares based on different techniques of spatial analysis in GIS software. For this mean, study area was divided in 1500 × 1500 m2 grid cells. Then, geographical coordinate of each grid recorded in UTM system. So, they were transferred into GPS for navigating to the exact excavation location. After soil sampling and transferring to the lab, their EC and PH were measured in saturation extract of soil samples. So, spatial distribution of soil sampling points was prepared in form of point map by GIS software. Generalization of point information to surface was performed using different interpolation algorithms and based on standards of Soil and Water Research Institute. Accuracy of interpolated maps was evaluated due to the MAE and MBE values. The results showed that the lowest observed error is related to the Spline method and therefore, this method was used for spatial modeling of salinity and alkalinity maps in the intended area. The research findings demonstrated that from total of 50,000 hectares, only 3066 hectares were without salinity and alkalinity limitation (6.1%), 9066 hectares had low salinity and alkalinity (18.1%); 17,772 hectares had average limitation for salinity and alkalinity (35.6%) and the remaining 20,096 hectares had high and very high limitation for salinity and alkalinity.

Bamboo Fungus-Derived Porous Nitrogen-Doped Carbon for the Fast, Sensitive Determination of Bisphenol A

Biomass-derived carbon materials have been considered as perfect substitutes for the traditional doped carbon materials, owing to its simple synthesis, rich-doped hetero-atoms, low cost and satisfactory electrochemical properties. In this paper, a rich nitrogen-doped carbon (NDC) material derived from bamboo fungus by simple carbonization was firstly applied for the electrochemical determination of Bisphenol A (BPA). NDC showed high catalytic activity towards the BPA oxidation for its rich doped nitrogen, high conductivity and porous structure. The morphology and structure features of NDC were characterized by the transmission electron microscopes and Raman spectrum. Meanwhile, the electrochemical properties of NDC modified glassy carbon electrode (GCE) and the behaviors of BPA on the NDC modified GCE (NDC/GCE) were estimated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimum conditions, differential pulse voltammetry (DPV) was used for the quantitative determination of BPA. A low detection limit (LOD) of 1.068 μM (IUPAC S/N = 3) was obtained within the range of 1.0 μM to 50.0 μM. And the NDC/GCE was further applied for the practical determination of BPA in soil extract samples successfully. The results revealed that the simple and sensitive NDC based platform could be a potential approach for the practical detection of BPA.

Is the zone of influence colonized by roots of neighboring species? Field tests in a Patagonian steppe

In general, there is more knowledge about aboveground structure and processes than about those belowground. It has been proposed that plants are belowground territorial and root segregation explains species coexistence. We explored this idea by studying root intermingling of perennial graminoid plants in an arid Patagonian steppe. We extracted soil samples under target species. Additionally, we buried root traps filled with sieved soil to quantify root colonization close to plants (zone of high influence), of five dominant graminoid species. We sorted root biomass by species from samples and traps using a root-trait taxonomic key with 95% accuracy. Both studies indicated that the zone of high influence is occupied by roots of target and neighbor species (1–4 species) but showed differences in relative biomass of species. After 4 months, species with high root RGR show dominance in traps. This soil pre-emption seems transitory because in the descriptive study dominant species predominated independently of target species. We propose that coexistence among active roots of several species could be explained by different soil occupation rates in the zone of high influence. More studies are needed in relation with resource use in order to comprehend relationship between above and belowground biomass distributions.

Characterization of colloidal arsenic at two abandoned gold mine sites in Nova Scotia, Canada, using asymmetric flow-field flow fractionation-inductively coupled plasma mass spectrometry

Asymmetric flow-field flow fractionation-inductively-coupled plasma-mass spectrometry was used to determine whether colloidal arsenic (As) exists in soil pore water and soil extract samples at two arsenic-contaminated abandoned gold mines (Montague and Goldenville, Nova Scotia). Colloidal arsenic was found in 12 out of the 80 collected samples (=15%), and was primarily associated with iron (Fe) in the encountered colloids. The molar Fe/As ratios indicate that the colloids in some samples appeared to be discrete iron–arsenic minerals, whereas in other samples, they were more consistent with As-rich iron (oxy)hydroxides. Up to three discrete size fractions of colloidal As were encountered in the samples, with mean colloid diameters between 6 and 14nm. The pore water samples only contained one size fraction of As-bearing colloids (around 6nm diameter), while larger As-bearing colloids were only encountered in soil extracts.

Molecularly imprinted polymer monolith containing magnetic nanoparticles for the stir-bar sorptive extraction of triazines from environmental soil samples

In this work, novel molecularly imprinted stir-bars based upon the entrapment of modified magnetic nanoparticles within an imprinted polymer monolith is developed for stir-bar sorptive extraction (SBSE). Firstly, magnetic nanoparticles were surface modified with oleic acid followed by encapsulation inside a silica network. Then, vinyl-groups were grafted onto the particles surface for the subsequent copolymerization with the imprinting polymerization mixture using a glass vial insert as a mold. As a result, the obtained imprinted monolith presented magnetic properties allowing its use as magnetic stir-bar. Variables affecting both polymer morphology (i.e., amount of magnetic nanoparticles, polymerization time) and binding-elution conditions of target analytes (i.e., solvents, time) was carefully optimized. Optimum imprinted stir-bars were evaluated for the SBSE of triazines in soil sample extracts. Recoveries, at 16ngg−1 concentration level, ranged from 2.4 to 8.7% with relative standard deviations lower than 15% (n=3). Although low recoveries were obtained, the high selectivity provided by the new molecularly imprinted stir-bars allowed reaching detection limits below 7.5ngg−1 by liquid chromatography coupled to UV detection.

Uptake of macro nutrients, barium, and strontium by vegetation from mineral soils on carbonatite and pyroxenite bedrock at the Lillebukt Alkaline Complex on Stjernøy, Northern Norway

AbstractCarbonatite originating from the Lillebukt Alkaline Complex at Stjernøy in Northern Norway possesses favorable lime and potassium (K) fertilizer characteristics. However, enrichments of barium (Ba) and strontium (Sr) in carbonatite may cause an undesired uptake by plants when applied to agroecosystems. A field survey was carried out to compare concentrations of Ba, Sr, and macronutrients in indigenous plants growing in mineral soil developed on a bedrock of apatite–biotite–carbonatite (high in Ba and Sr) and of apatite–hornblende–pyroxenite (low in Ba and Sr) at Stjernøy. Samples of soil and vegetation were collected from three sites, two on carbonatite bedrock and one on pyroxenite bedrock. Ammonium lactate (AL)‐extracted soil samples and nitric acid microwave‐digested samples of soil, grasses, dwarf shrubs, and herbs were analyzed for element concentration using ICP‐MS and ICP‐OES. Concentrations of magnesium (Mg) and calcium (Ca) in both soil (AL) and plants were equal to or higher compared to values commonly reported. A high transfer of phosphorus (P) from soil to plants indicates that the apatite‐P is available to plants, particularly in pyroxenite soil. The non‐exchangeable K reservoir in the soil made a significant contribution to the elevated K transfer from soil to plant. Total concentrations of Ba and Sr in surface soil exhibited a high spatial variation ranging from 490 to 5,300 mg Ba kg−1 and from 320 to 1,300 mg Sr kg−1. The transfer of AL‐extractable elements from soil to plants increased in the order Ba < Sr < Ca < Mg < K, hence reflecting the chemical binding strength of these elements. Concentrations of Ba and Sr were low in grasses (≈ 20 mg kg−1), intermediate in dwarf shrubs and highest in herbs. Plant species and their affinity for Ca seemed more important in explaining the uptake of Ba and Sr than the soil concentration of these elements. The leguminous plant species Vicia cracca acted as an accumulator of both Ba (1.800 mg kg−1) and Sr (2.300 mg kg−1).

The origin of radon anomalies along normal faults in an active rift and geothermal area

Radon anomalies are widely reported in the vicinity of active faults, where they are often inferred to result from upward migration of fluids along fault zones. We examine the up-fault flow hypothesis by measuring radon (220Rn and 222Rn) in soil gas above two active normal fault zones within the central Taupo rift, New Zealand. In agreement with previous investigations, we find that the average concentrations of both radon isotopes are generally higher near mapped faults, although in some cases we find that the difference with background populations is not significant. Soil samples recovered from 1 m depth indicate that some of the radon anomalies along faults may reflect local changes in soil types. The 220Rn isotope emanation measured from extracted soil samples shows a linear correlation with the field concentration measurements (R2 = 0.90, p value = 3 × 10–6), whereas 222Rn emanation shows no linear correlation (R2 = 0.17, p value = 0.17). The soil gas isotopes measured show a significant linear correlation of 220Rn and 222Rn concentrations (R2 = 0.44–0.55, p value 90% of the soil gas measurements, showing that a majority of radon anomalies along faults are not necessarily caused by advection of gases along fault planes and can be explained by an increase in radon soil emanation. However, diffusion cannot account for all of the observed patterns in the data, and in some specific locations along faults, 222Rn concentrations are most likely produced by advective flow of subsurface gases, suggesting channelized gas flow in portions of some faults.

A mobile lab-on-a-chip device for on-site soil nutrient analysis

In this paper, a mobile sensor for on-site analysis of soil sample extracts is presented. As a versatile tool for scanning ion concentrations in liquid samples, it especially allows the analysis of NO3, NH4, K and PO4. The sensor mainly consists of a microfluidic chip in which the sample ions are separated in an electric field (capillary electrophoresis) and the individual ion concentrations are detected by a conductivity measurement. For the adaption of the device to field conditions, two major concerns were addressed. Firstly, nano-porous material was used as a barrier between the sample container and the analysis channel of the microfluidic chip. This prevents pressure driven leakage of the sample into the chip due to non-horizontal orientation of the device. Secondly, a new method for the injection of the sample into the chip was used. It reduces the number of fluidic connections between chip and operation device to three instead of the commonly used four connections. The sensor performance was tested on multi-ion solutions with calibration series for NO3, NH4, K and PO4. For the first on-site test, a quick soil nutrient extraction procedure with water was used. The sensor data was compared to standard laboratory results. The potential of the sensor for soil nutrient analysis is discussed together with required improvements of the sensor performance and of the nutrient extraction procedure.

The role of Pteridium arachnoideum(Kaulf) on the seed bank of the endangered Brazilian Cerrado

The native bracken (Pteridium arachnoideum) often occurs in mono-specific stands in the Brazilian Cerrado, and this dominance can impact on both the above-ground vegetation and soil seed bank. This study investigated how invasion by this species over a 20-year period changed the seed bank and the relationship between the seed bank and litter mass. We extracted soil samples from three replicated invaded and uninvaded sites, and followed seedling emergence for six months. We collected the above-ground biomass and litter of P. arachnoideum in ten 1m2 plots from three invaded sites. There was no difference between invaded and uninvaded areas in seed bank richness, diversity or overall abundance. The most abundant family was the Melastomataceae, followed by the Poaceae. The Melastomataceae was more abundant in uninvaded sites, but the most common species of this family (Tibouchinastenocarpa) was not affected. The grasses were more common in invaded sites in the rainy season and were affected by heterogeneity in the litter layer. The seed bank could play a role in the recovery of these invaded areas, but the presence of weeds and invasive grasses could constrain their use as a management strategy.

Nano-Phytotechnological Remediation of Endosulfan Using Zero Valent Iron Nanoparticles

Endosulfan, an organochlorine pesticide, is known for its toxicity and ability to accumulate in the environment. In India endosulfan was banned only in 2011 and hence toxic residues are still persistent in the environment. The abilities of three plant species Chittaratha (Alpinia calcarata), Tulsi (Ocimum sanctum), and Lemongrass (Cymbopogon citratus) to remove endosulfan from soil in the absence and presence of zerovalent iron nanoparticles (nZVIs) (1000 mg/Kg of soil), i.e., by phytoremediation and nano-phytoremediation, were determined. Extracted soil samples from the experimental plot were analyzed using Gas Chromatograph with Electron Capture Detector (GC-ECD) and final dehalogenated product was confirmed by Mass Spectrometer (MS). A. calcarata had the best efficiency compared to the other two plant species and the efficiency decreased in the order A. calcarata > O. sanctum> C. citrates. The initial endosulfan removal rate was high (82% was removed within 7 days) when nano phytoremediation experiments were conducted with A. calcarata but then gradually decreased, probably because the activity of nZVI decreased over time. The nZVI endosulfan degradation mechanism appears to involve hydrogenolysis and sequential dehalogenation which was confirmed by GC-MS analysis. Only small amounts of endosulfan were accumulated in the plants because the added nZVIs might have promoted the reductive dechlorination of endosulfan.

The Bioavailability of Manganese in the Marigold <i>(Calendula officinalis L.)</i> Grown on Alkaline Soil

The research includes analysis of: pH value, organic matter content, and the total concentration of manganese in eleven soil samples from different localities northeast of Bosnia and Herzegovina. Sequential extractions of soil samples were also performed to determine the content of some form of binding manganese. Concentration of manganese in the flowers of calendula were also found and tested at these sites. From the obtained measurement, BCF (Bioconcentration Factor) values were calculated for the tested metal. Soil pH had values from 7.84 to 8.54, which puts them in the category of alkaline and strongly alkaline soil. The total concentration of manganese measured in soil samples do not exceed the limit values or are above average values. In the analyzed soil samples, the minimum content of manganese in the exchangeable fraction and the largest in the residual fraction and bound for oxides of manganese and iron. The concentrations of manganese in the flowers of calendula have not exceeded the permitted value. Statistical analysis of the results showed a weak linear correlation between pH value of an aqueous solution of the soil and the content of manganese in the flower, and linear correlation between manganese in the exchangeable fraction and the content of manganese in the flower. The calculated BCF values are very low and suggest that calendula growing on alkaline soil hasn’t got an expressed potential for accumulation of manganese.

Sheep grazing and soil bacterial diversity in shrublands of the Patagonian Monte, Argentina

Our objective was to assess whether long-term continuous sheep grazing was associated with the bacterial community of the Patagonian Monte soils. We randomly extracted soil samples from 5 plant-covered patches (PCP) and the nearest inter-canopy areas (IC) at sites with low (L), moderate (M) and heavy (H) grazing intensity. Bacterial communities were evaluated by denaturing gradient gel electrophoresis (DGGE) and dominant bands were sequenced. Dendrograms showed a different association among grazing sites in PCP compared to IC areas. In PCP, M and H sites were clustered and DGGE revealed a high similarity in the bacterial community regardless of grazing intensity. In IC areas, analyses clustered L and M sites. Band sequencing revealed that members of these communities belonged to Sphingobacteria, Solibacteres, Gammaproteobacteria, Betaproteobacteria and Bacilli. Some of the band sequences related to Nitrosococcus oceani and Nitrosococcus watsonii which are restricted to marine environments and salt lakes. Microcoleus vaginatus and diatom chloroplast-related sequences were mainly detected in IC areas from L and M. Heavy grazing could alter autotrophic bacteria/diatom composition in IC areas possibly due to physical disturbance of biological crusts by trampling, threatening the potential of crust re-formation. Grazing intensity affected soil bacterial communities differently in PCP and IC areas with soil crust, highlighting the importance of improving our understanding of microbial diversity responses to land use.

Assessment of the mobile forms of zinc and copper content in soil samples from areas of different land use on example of the Krasnogvardeisky District of the St. Petersburg

The present study investigated the actual content of Zn and Cu mobile fractions (buffer extractable) in soils of different land use scenarios within the Krasnogvardeisky District of the Saint Petersburg (Russia). The data were obtained via Atomic Adsorption Spectrophotometry, analyzing ammonium acetate buffer extracts (pH 4.8) of soil samples collected. The buffer-extracted metals are considered to be the most mobile fractions at given soil pH conditions. The results have shown low concentrations of mobile Zn and Cu in soils of recreational, agricultural and even industrial areas, fluctuating relative to the local area soil background values (Zn = 1.2; Cu = 2.70 mg kg−1). Substantial levels of contamination were found in the loamy sand Technosol of residential land use amended with composted municipal solid wastes and savage sludge. Calculated geo-accumulation indices (I geo), pollution indices (PI) and contamination factors (C f) were of the higher values, indicating moderate to extremely high pollution levels with the mobile trace metals. Median topsoil metal concentrations three times exceeded the maximal permissible concentrations for soils (Zn = 23.00; Cu = 3.00 mg kg−1), reaching the maximal values of 69.58 mg kg−1 for Zn and 10.17 mg kg−1 for Cu, respectively.

Schwertmannite in soil materials: Limits of detection of acidified ammonium oxalate method and differential X-ray diffraction

Schwertmannite is a secondary iron mineral, found in acid mine drainage (AMD) and acid sulfate soils (ASS), that generates acidity when it transforms to stable mineral phases. Acidity liberated during schwertmannite transformation can seriously diminish water quality and soil health. Acidified ammonium oxalate (AAO) extraction in the dark coupled with differential X-ray diffraction (DXRD) analysis is routinely used to identify and to quantify poorly crystalline iron oxide phases such as schwertmannite in AMD environments. However, management of ASS environments is largely impacted due to lack of reliable methods to identify/quantify schwertmannite in soil materials. Our study aimed to evaluate the 15min AAO extraction method to identify/quantify schwertmannite in soil materials. We extracted soil samples spiked with synthetic and natural schwertmannite (termed as natural organic rich schwertmannitic material) with acidified ammonium oxalate (AAO) for 15min. We also examined soil samples spiked with schwertmannite through the DXRD analysis under ideal conditions assuming that only schwertmannite would dissolve during the extraction. Our data show that synthetic schwertmannite dissolved partially during the 15min AAO extraction and as a result the recovered Fe content from schwertmannite-spiked soils was underestimated by ~20%. The data also show that soil materials could also influence the recovery of schwertmannite. Fe/S molar ratios of schwertmannite spiked at higher rates (2% and 5%) were closer to the expected ratios. In addition to schwertmannite, goethite and other unidentified minerals in natural organic rich schwertmannitic material also dissolved during the 15min extraction time. The DXRD analysis data show that schwertmannite in soil materials at contents >5% may be identifiable through this approach. Our findings highlight that both the 15min AAO extraction procedure and the DXRD analysis have limited applicability towards detecting schwertmannite accurately in soil materials.

Study on speciation and salinity-induced mobility of uranium from soil

A study was carried out to investigate the impact of salinity on mobility of uranium (U) in soil and the mechanism involved. In order to explore the involved process, speciation study was carried out and it confirmed that U was present in the moderately reduced soil as a mixture of U(IV) and U(VI) with U(IV) as dominating (71 %) state. Sequential extraction of soil samples showed that major fraction is bound to clay mineral (49.31 %) followed by oxides and hydroxide of Fe/Mn (19.58 %), organic phase (10.75 %), exchangeable (10.41 %) and remaining to carbonate phase (9.96 %). The speciation study of U(VI) in soil solution revealed that UO2CO3, (UO2)2CO3(OH)3−, UO2(CO3)22−, UO2OH+ and UO2(OH)2 are predominate species in the ambient condition. The effect of salinity induced by CaCl2, MgCl2, NaCl, NaNO3 and Na2SO4 on the mobility of uranium elucidates that increases in ionic strength mobilize U(VI) from soil exchange sites forcing it into solution. Although the desorption capacity of cations is directly proportional to ionic radius (Ca2+ > Mg2+ > Na+) and strength of solution it fails in case of Na2SO4 and NaNO3. It was observed that at high salinity, U is removed from solution as Na2U2O7 (s) at near neutral pH. At high salinity NaNO3 induces highest desorption of U from soil subjected to its oxidizing properties. The study confirms that ion exchange mechanism is involved in the desorption of U from soil CaCl2, MgCl2, NaCl, Na2SO4 whereas NaNO3-induced uranium desorption involves both ion exchange mechanism as well as oxidative dissolution of U(IV) bound to Fe/Mn− oxides and organic matter.