Mobility Of Cadmium Research Articles

Effect of Surfactant on Adsorption and Mobility of Lead and Cadmium in Soils

Effect of Surfactant on Adsorption and Mobility of Lead and Cadmium in Soils

Mobilization of cadmium from Festuca ovina roots and its simultaneous immobilization by soil in a root-soil-extractant system (in vitro test)

ABSTRACTMobilization of cadmium accumulated in Festuca ovina L. roots and simultaneous immobilization of this metal by soil were studied in three chambers connected into one system containing: (1) roots in an extractant solution, (2) soil in an extractant solution, and (3) extractant solution alone. Six extractants sterilized by filtration were used: 0.1 M NaNO3 (NA), 0.1 mM desferrioxamine B (NA + DFOB) and 1 mM citric acid (NA + CA) in NA, and a water extract of soil (SE) supplemented with the same compounds. SE mobilized 53% of the Cd introduced to the system with roots. The addition of DFOB or CA to SE increased Cd extraction from roots by 17%, while the same compounds introduced to NA did not change mobilization of Cd (60% efficiency). Regardless of the extractant used, mobilization of Cd from roots was about 25% lower when extraction was done in a control system without soil. The metal released from roots was gradually immobilized by the soils loaded into all systems during a 4-day incubation. Sequential extractions of Cd from the soils showed that the metal released from roots with NA was stabilized mainly by soil Mn and Fe oxides, while that released with SE was stabilized by soil organic matter.

Metal Extractability in Binary and Multi-metals Spiked Calcareous Soils

ABSTRACTIn the present study, a laboratory experiment was designed to compare the 0.01 M calcium chloride (CaCl2) and diethylenetriaminepentaacetic acid (DTPA) extraction methods for their ability to predict cadmium (Cd), copper (Cu), iron (Fe), Manganese (Mn), nickel (Ni), and zinc (Zn) availability and mobility in five calcareous soils. The soils were spiked with different amounts of metals (0, 50, 100, 200, and 400 mg kg−1) both in binary (Cu and Zn; Ni and Cd; Fe and Mn) and in multi-systems (Cd, Cu, Fe, Mn, Ni, and Zn) and incubated for 1 months at field capacity. In metal-spiked soils, both extraction methods showed a linear relationship of extractable to total metals for all soils. The fraction of total metals extracted by DTPA was much higher than the fraction extracted by CaCl2, which was attributed to the formation of soluble metal-complexes in the complexing extracts calculated by the Visual Minteq program. DTPA extraction method showed higher selectivity for Cu over other metals both in binary and in multi-systems. Different order of metals extractability was found in binary and multi-systems for both extraction methods. Solid/solution distribution coefficient (Kd) was calculated by the ratio of the solid phase to soil solution concentration of metals extracted by CaCl2 or DTPA extraction methods. Both in binary and in multi-systems, the average Kd (l kg−1) of metals by soils were in the order of Mn (5398) > Fe (4413) > Zn (3376) > Cu (2520) > Ni (969) > Cd (350) in the CaCl2-extractable metals and Fe (35) ≥ Ni (34) > Zn (18) > Mn (11.2) > Cu (6.3) > Cd (4) in the DTPA-extractable metals. Results showed that among the six studied metals, Cd had the lowest Kd, implying a relative higher mobility in these calcareous soils. The Visual Minteq indicated that in the CaCl2-extraction method and in both binary and multi-systems the dominant species for Cu, Mn, Ni, and Zn were Cu2+, Mn2+, Ni2+ and Zn2+, respectively, while for Cd and Fe, the dominant species were CdCl+ and Fe(OH)2+, respectively.

Remediation of agrosoddy-podzolic soils contaminated with cadmium

Results of a long-term field experiment on the remediation of agrosoddy-podzolic soils (Retisols) contaminated with cadmium have been analyzed. The solidification/stabilization method (S/S technology) has been used for the development of remediation technology. Different rates of ameliorants and fertilizers (limestone and phosphorite meals, superphosphate, sodium sulfide, peat, and zeolite) have been studied as ameliorating additives. It has been shown that the efficiency of ameliorating additives in decreasing the mobility of cadmium in the soil depends on their type (the dissolution of ameliorant in water and solubility products of the resulting Cd compounds), application rate, and the time elapsed since the application. In the first year of the experiment, the highest efficiency has been observed for water-soluble forms of ameliorating additives: sodium sulfide and superphosphate. Limestone meal and zeolite have showed the longest aftereffect. The application of all ameliorating additives under study has increased the yield of agricultural crops and reduced their cadmium content down to below the MPC level in most cases, which makes this agronomic practice promising for the remediation of agricultural lands with an elevated content of cadmium.

Compost and sulfur affect the mobilization and phyto-availability of Cd and Ni to sorghum and barnyard grass in a spiked fluvial soil

Soil reclamation via additives can cause contradictory effects on the mobilization of toxic elements in soils under dry and wet conditions. Therefore, our aim was to investigate the impact of compost and sulfur in two rates (1.25 and 2.5%) on fractionation, mobilization, and phyto-availability of cadmium (Cd) and nickel (Ni) to sorghum (dry soil) and barnyard grass (wet soil) in a fluvial soil spiked with 25mg Cd or 200mg Ni/kg soil. Compost decreased the solubility and mobilization of Cd (especially in dry soil) and Ni (in both soils). Sulfur increased the solubility of Cd (31% in dry soil-49% in wet soil) and Ni (4.6% in wet soil-8.7% in dry soil). Sulfur altered the carbonate fraction of Cd to the soluble fraction and the residual fraction of Cd and Ni to the non-residual fraction. Compost decreased Cd and increased Ni in sorghum, but enhanced Cd and degraded Ni in grass. Sulfur increased Cd and Ni in both plants, and the increasing rate of Cd was higher in grass than in sorghum, while Ni was higher in sorghum than in grass. These results suggest that compost can be used as an immobilizing agent for Cd in the dry soil and Ni in the wet soil; however, it might be used as mobilizing agent for Cd in the wet soil and Ni in the dry soil. Sulfur (with rate 2.5%) can be used for enhancing the phyto-extraction of Cd and Ni (especially Cd) from contaminated alkaline soils.

Influence of Organic Manure and Lime on Cadmium Mobility in Soil and Uptake by Spinach (Spinacia oleracea L.)

ABSTRACTSpinach grown in cadmium (Cd)-contaminated soils accumulates Cd compounds in toxic concentration contaminating the food chain leading to the chronic toxic effects on human and animal health. A study was conducted in a Cd-contaminated soil to examine the ameliorative effect of lime and organic manure on the mobility of Cd and its uptake in spinach. Application of lime or organic manure or both decreased the Cd concentration in soil and shoots and increased chlorophyll content of leaves. As compared to the control treatment, combined application of lime and organic manure decreased the level of Cd in soil by 54.7%, in spinach shoot by 61.3%, and the transfer factor of Cd by 35.0% and increased in leaf chlorophyll content by 29.4%. Combined application of lime and organic manure emerged as a viable option in reducing the mobility of Cd in contaminated soil for growing spinach.

CASE STUDY: EFFECT OF COMPOST AND HUMIC ACID IN MOBILITY AND CONCENTRATION OF CADMIUM AND CHROMIUM IN SOIL AND PLANT

The effect of compost and humic acid in mobility and concentration of cadmium and chromium in contaminated soil were investigated. Experiment was carried out with three levels of soil cadmium and chromium and two organic matters (compost and humic acid). The study was performed in a randomized complete block design with 3 replicates. Results indicated that application of organic substances enhanced movement of cadmium and chromium in soil column. Humic acid is more effective than compost on the mobility of cadmium and chromium in soil. Mobility of cadmium and chromium in the lower depths of soil column were increased. Cadmium and chromium concentration in shoots and roots enhanced due to increasing those concentration in soil and application of organic substances. Increase in cadmium in shoots can be attributed to the high mobility of this element in maize plant. Maize root chromium concentration was greater than shoot chromium concentration. Humic acid was more effective than compost as cadmium and chromium concentration in root and shoot was concerned. Low mobility of chromium in plant and accumulation of chromium in roots can be reasons of decreasing of chromium concentration in shoot of plant and its bioaccumulation.

Modeling Copper and Cadmium Mobility in an Albeluvisol Amended with Urban Waste Composts

Core Ideas Mobility of Cu and Cd in compost‐amended soil was estimated using HYDRUS‐2D. Cu and Cd mobility was controlled by sorption in the tilled layer. Different sorption estimations were used to model trace metal leaching. EDTA/CaCl2 extracts ratio gave reliable Kd estimates for Cu but not for Cd. Most of the Cu and Cd mass remained in the tilled layer. Two experimental plots amended with a co‐compost of sewage sludge and green wastes (SGW) or with a municipal solid waste compost (MSW) were compared with a control plot without organic amendment (CONT) in terms of trace metals mobility. These plots were equipped with wick lysimeters, time‐domain reflectometry probes and tensiometers for 6 yr (2004–2010). Different soil structures due to tillage and compost incorporation were identified in the tilled layers and reproduced in HYDRUS‐2D for simulating water, Cu, and Cd transport. Two sorption estimation approaches were used, either assuming equilibrium between CaCl2 and ethylenediaminetetraacetic acid (EDTA) extractable metals (Kd‐1) or using equations based on pedotransfer functions assuming nonlinear sorption for Cu (Kf) and linear sorption for Cd (Kd‐2). Lysimeter data on Cu leaching were successfully reproduced with the Kd‐1 approach for the SGW and CONT plots (model efficiency coefficient ESGW = 0.97, ECONT = 0.95), while the MSW plot showed better fitting with the Kf approach (EMSW = 0.77), which could be explained by the less stable organic matter of the MSW compost because it takes into account organic matter components (dissolved organic C and soil organic matter). The Cd leaching was reproduced with the Kd‐2 approach for the two amended plots (ESGW = 0.12, EMSW = 0.80), while CONT simulation overestimated leaching. The percentage of measured Cu and Cd leached in reference to input mass was 0.6 and 2.7%, respectively, in the SGW plot compared with 5% for both metals in the MSW plot. Trace metal mobility appeared to be limited in the tilled layer by sorption to organic matter.

Effect of Phosphates on the Bioavailability and Phytotoxicity of Pb and Cd in Contaminated Soil and Phytoextraction by Vetiver Grass

AbstractColumn and vessel experiments were conducted to investigate changes in mobility, leaching, and availability of lead (Pb) and cadmium (Cd) in contaminated soil (Santo Amaro Municipality, Bahia State, Brazil) after treatment with different sources of phosphate followed by assessment of phytoextraction by vetiver grass [Vetiveria zizanioides (L.)]. Columns were filled with contaminated soil and KH2PO4 (T1 treatment), reactive natural phosphate fertilizer (NRP) (T2 treatment), KH2PO4 mixed with NRP (T3 treatment), and untreated contaminated soil used as reference soil (T0 treatment). After 60 days, soil samples were collected from each column every 10 cm in depth and vessel experiments were initiated by planting vetiver grass. After 90 days, Pb and Cd were extracted from the soil and from the plant tissues using diethylenetriaminepentaacetic acid (DTPA) and nitro-peroxide extraction, respectively. Metal mobility was assessed using two methods: the toxicity characteristic leaching procedure (TCLP) and ...

Predicting Mobility of Cadmium (Cd) and Lead (Pb) in Contaminated Soil through a Mathematical Model

Predicting Mobility of Cadmium (Cd) and Lead (Pb) in Contaminated Soil through a Mathematical Model

Effects of algae growth on cadmium remobilization and ecological risk in sediments of Taihu Lake

Indoor simulation experiment with 2.76 L microcosms using sediment from Taihu Lake were conducted to investigate the relationship between algae bloom and heavy metals release into a lake aquatic environment. The results showed that Microcystic aeruginosa (M. aeruginosa) growth can enhance cadmium (Cd) mobilization from sediments to overlying water due to increasing pH and DO content of overlying water and changing the redox condition of surface sediment (0–2 cm) from weak oxidation to weak reduction. The dissolved Cd concentration in overlying water can be decreased during algal growth process. The remobilization of Cd from sediment can effectively reduce the ecological risk of total Cd in sediments. The results of this study showed that both Igeo and Eri can be used to effectively evaluate the ecological risk of heavy metal Cd in different fractions.

Impact of pigeon pea biochar on cadmium mobility in soil and transfer rate to leafy vegetable spinach.

Introduction of heavy metals in the environment by various anthropogenic activities has become a potential treat to life. Among the heavy metals, cadmium (Cd) shows relatively high soil mobility and has high phyto-mammalian toxicity. Integration of soil remediation and ecosystem services, such as carbon sequestration in soils through organic amendments, may provide an attractive land management option for contaminated sites. The application of biochar in agriculture has recently received much attention globally due to its associated multiple benefits, particularly, long-term carbon storage in soil. However, the application of biochar from softwood crop residue for heavy metal immobilization, as an alternative to direct field application, has not received much attention. Hence, a pot experiment was conducted to study the effect of pigeon pea biochar on cadmium mobility in a soil-plant system in cadmium-spiked sandy loam soil. The biochar was prepared from pigeon pea stalk through a slow pyrolysis method at 300 °C. The experiment was designed with three levels of Cd (0, 5, and 10 mg Cd kg(-1) soil) and three levels of biochar (0, 2.5, and 5 g kg(-1) soil) using spinach as a test crop. The results indicate that with increasing levels of applied cadmium at 5 and 10 mg kg(-1) soil, the dry matter yield (DMY) of spinach leaf decreased by 9.84 and 18.29 %, respectively. However, application of biochar (at 2.5 and 5 g kg(-1) soil) significantly increased the dry matter yield of spinach leaf by 5.07 and 15.02 %, respectively, and root by 14.0 and 24.0 %, respectively, over the control. Organic carbon content in the post-harvest soil increased to 34.9 and 60.5 % due to the application of biochar 2.5 and 5 g kg(-1) soil, respectively. Further, there was a reduction in the diethylene triamine pentaacetic acid (DTPA)-extractable cadmium in the soil and in transfer coefficient values (soil to plant), as well as its concentrations in spinach leaf and root, indicating that cadmium mobility was decreased due to biochar application. This study shows that pigeon pea biochar has the potential to increase spinach yield and reduce cadmium mobility in contaminated sandy soil.

Fractionation and mobilization of toxic elements in floodplain soils from Egypt, Germany, and Greece: A comparison study

Determining the chemical fractions of toxic elements (TEs) in soils is important to evaluate their mobilization and bioavailability. In this study, samples from three representative floodplain soils located close to the Rivers Nile (Egypt), Elbe (Germany), and Pinios (Greece) were used to link the soil formation and properties to the geochemical fractions and mobilization of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in these soils. The Elbe soil showed the highest total concentration of the elements except for Ni, in which the Pinios soil had the highest amount. A significant amount (55–94%) of the elements was present in the Elbe soil in the potentially mobile (non-residual) fraction, while the amount of this fraction ranged between 9 and 39% in the Pinios soil and between 9 and 34% in the Nile soil. In the Elbe soil, most of the non-residual Ni, Pb, and Zn was associated with the Fe-Mn oxide fraction, while Cd was distributed in the soluble plus exchangeable fraction and Cu in the organic fraction. In the Nile and Pinios soils the Fe-Mn oxide fraction was the abundant pool for Cu, Ni, Pb, and Zn whereas Cd had the highest amount in the soluble plus exchangeable as well as in the carbonate fractions.

Effect of dried olive pomace – derived biochar on the mobility of cadmium and nickel in soil

This study aims to evaluate dried olive pomace derived biochar as a potential soil amendment for cadmium and nickel immobilization. Biochar was produced through pyrolysis under oxygen-limited conditions, at 400°C (BC400) and 700°C (BC700). Batch sorption/desorption experiments were conducted, investigating different agitation times (30–1440min), initial metal concentration in the solution (100–3000μM) and desorption pH (2–7). Results showed that by amending soil with biochar at increasing rates, enhanced sorption and decreased desorption of both metals were observed. In fact, biochar addition resulted in increased soil pH, possibly enhancing not only metal adsorption on soil surfaces (minerals or oxides), but also metal precipitation. Modeling results concerning sorption equilibrium corroborated this statement. Amended samples showed higher metal retention even at low pH values. Both biochars enhanced the ability of soil to immobilize cadmium and nickel, however in most cases BC700 was proven to be more efficient.

Reconstruction of the Cadmium Contamination History of a River Floodplain from Maoniuping Mining Area (China) by Gamma Ray Spectrometry and Inductively Coupled Plasma Mass Spectrometry

The Maoniuping rare earth elements deposit is the second largest rare earth elements deposit in China, and the third largest in the world. A sediment core was collected from the river floodplain downstream from the Maoniuping rare earth elements mining area (Sichuan Province, China) to reconstruct the cadmium contamination history and trace its contamination source. Based on lead-210 (210Pb) dating by gamma ray spectrometry and elements determination with inductively coupled plasma mass spectrometry of the sediment core, it was found that the cadmium accumulation rate of the flood plain increased from 0.16 to 2.22 µg cm−2 yr−1 over the past 100 years. Combining aspects of time, space, and element composition information, it is proved that the exploitation of Maoniuping rare earth elements deposit was the main reason for the increase. Moreover, to evaluate the mobility and availability of cadmium in the sediment core, the modified European Communities Bureau of Reference sequential extraction procedure in combination with inductively coupled plasma mass spectrometry was applied. Risk assessment code was used to further assess the environmental risk of cadmium in the sediment. It was found that the environmental risk from cadmium was high in the surface of the sediments. The results from gamma ray spectrometric and mass spectrometric methods may provide important information for the control and remedy of cadmium-related pollution areas.

Cadmium Mobility with Persulfate Chemical Oxidation: Effects of Soil Properties and Activation Methods

The potential effects of persulfate in situ chemical oxidation (ISCO) on metals and on long-term groundwater quality is an important issue because of the potential risks to public health and to the environment. Application of persulfate and its activation amendments to soil and groundwater can lead to complex interactions, altering geochemical conditions and processes, thereby affecting metals mobility. The mobility of cadmium sorbed on three soils varying in physical–chemical properties was investigated after chemical oxidation by unactivated and activated persulfate using mixed batch reactors. Each of the three soils was treated with two different concentrations of persulfate, 2.1 mM and 42 mM, and different activation amendments that included Fe(II), Fe(II)-EDTA, and high pH. Resulting solutions were analyzed for soluble cadmium after 48 h and 6 months. Results show that cadmium mobilization varied with the persulfate activation method and the soil type. The maximum amount of cadmium was mobilized with Fe(II)-EDTA activation and the least amount of cadmium was mobilized with high pH activation. In addition to Fe(II)-EDTA activation, cadmium was more mobile in soil with low soil organic carbon and low mineral content. Enhanced cadmium desorption at low pH and formation of soluble cadmium-EDTA complexes are the main mechanisms of cadmium mobilization from soils with persulfate ISCO.

Assessing the Mobilization of Cadmium, Lead, and Nickel Using a Seven-Step Sequential Extraction Technique in Contaminated Floodplain Soil Profiles Along the Central Elbe River, Germany

The mobilization of toxic metals in soils strongly depends on their bounding in different geochemical fractions. However, the relations between soil properties and the vertical horizon-specific distribution of different geochemical fractions of cadmium (Cd), lead (Pb), and nickel (Ni) in various floodplain soil types are limited and have not been studied up to date. Therefore, seven soil profiles in three areas along the Elbe River, Germany, which represent the two soil groups Mollic Fluvisols and Eutric Gleysols, were selected to determine geochemical fractions of Cd, Pb, and Ni. A sequential extraction procedure which fractionate metals into the seven fractions: F1: soluble+exchangeable, F2: easily mobilizable, F3: bound to Mn oxides, F4: bound to soil organic matter, F5: occluded into amorphous Fe oxides, F6: occluded into crystalline Fe oxides, and F7: residual fraction was used. Concentrations of pseudo-total Cd, Ni, and Pb were exceeded the international trigger action values and governed mainly by soil organic carbon (SOC), cation exchange capacity, and Fe–Mn sesquioxides. The mobile fraction (∑F1–F2) was dominant for Cd, whereas Pb was mainly bounded in F4/F5, and Ni in F7/F6. Cadmium and Pb reveal a higher potential mobility (∑F1–F6) than Ni. The potential mobile fraction ranged from 90 % to 97 %, 44 % to 61 %, and 83 % to 92 % of the (pseudo)total Cd, Ni, and Pb, respectively. The Gleysols showed a higher mobile fraction and potential mobile fraction than Fluvisols. The mobile fraction of the metals correlated positively with clay, SOC, and total sulfur (St), and negatively with pH and Fe–Mn oxides. Our results indicate that the studied soils exhibit elevated concentrations of Cd, Ni, and Pb, as well as a high potential mobilization of these metals. Our findings suggest that a release of these toxic metals in floodplain soils should be considered due to an increased mobilization and the potential environmental risks such as uptake by plants, and thus, the transfer of these metals into the grassland and food chain, as well as transport via waters during periods of flooding.

Preliminary assessment of cadmium mobility in surface sediments of a tropical estuary

Cadmium is a toxic metal often found with a strong enrichment factor in coastal sediments. The sequential extraction procedure proposed by the BCR (Community Bureau of Reference) was applied for partitioning of Cd in tropical estuary sediments. The method showed satisfactory recoveries. The repartition of Cd in different phases of sediment was controlled by the residual phase (50.32 to 67.45 %). However, the exchangeable and acid soluble fraction (F1) was in general found to be the second most abundant fraction in the surface sediments (11.14 to 15.24 %), indicating that an important portion of Cd could be remobilized, thus becoming available to aquatic biota. Cd also showed different distribution patterns in the sediment phases due to the heterogeneity of the sediments, as well as the physical and chemical conditions along with the different sources of Cd in the bays. The risk assessment code investigation showed a medium risk of Cd in the estuary. KEY WORDS : Cadmium, Mobility, Sediment toxicity, Sequential extraction Bull. Chem. Soc. Ethiop. 2014 , 28(2), 245-254. DOI: http://dx.doi.org/10.4314/bcse.v28i2.8

Efecto de la calidad de la materia orgánica asociada con el uso y manejo de suelos en la retención de cadmio en sistemas altoandinos de Colombia

Cadmium from soils by weathering and anthropogenic activities can have produce toxic effects associate to low affinity of adsorbents forms, high solubility and mobility. It is very important to conduct studies leading to knowledge of adsorption phenomena and cadmium mobility factors and predict possible toxici-ty in High Andeansoils whose use is changing to pastures and crops with applications of phosphate fertilizer with presence of Cd in composition. High Andean soils subbasin Rio Las Piedras, (Department of Cauca), with systems of forest, crop and pasture were characterized by physical and chemical properties, highlighting strong acidity, presence of allophones, high in organic carbon, high cation exchange capacity, low density of soil. The quality of soil organic matter was assessed by different humification index obtained with the different fractions characterized to determine the influence on cadmium retention phe-nomenon and mobility factor. The retention was evaluated by Freundlich adsorption isotherms in humic acids and soils of the three systems. The K (maximum adsorption capacity) and n (retention force) values correspond to 131. 98 and 1.18 in forest soils, 340.93 and 1.19 for crop, 170.36 and 1.19 in pasture, and are lower than those of humic acids in the three systems. The quality of the organic matter has a significantly effect on these processes, better quality results in less mobility preventing groundwater contamination and bioaccumulation toxicity.

Effectiveness of different meliorants to reduce the degree of heavy metal mobility in polluted agrozem

Various meliorants are shown to reduce the degree of lead and cadmium mobility in polluted agrozem by 20–60% on average. Sodium sulfide and superphosphate at doses of 120 kg of active ingredient per/ha (a.i./ha) and phosphorite meal at a dose of 1.5 t/ha somewhat stand apart in the effectiveness of this action.