Cobalt In Soils Research Articles

Assessment of copper, cobalt and zinc contaminations in soils and plants of industrial area in Esfahan city (in Iran)

The infiltration of heavy metals into soils through steel plant production processes is one of the most important soil pollution sources. The aim of this study was to determine copper (Cu), cobalt (Co), and zinc (Zn) concentrations in soil and plant shoots around the Esfahan steel company (ESC). In this study, we separated 17 zones based on soil maps and marked 54 points for soil sampling. Samples were collected from each point at 0–5, 5–10, 10–20 and 20–40 cm depths and DTPA-extractable concentrations of Cu, Co, and Zn were determined. Also 162 plant samples from shoots of 13 main plant species were collected and the concentrations of Cu, Co, and Zn were determined. The results showed that the maximum concentrations of Cu, Co, and Zn were 9.2, 2.4, and 10 mg kg−1 soil at the depth of 0–5 cm. A comparison of the heavy metal contents at different levels showed Cu, Co, and Zn contamination in soil profile, especially in topsoil (0–20 cm) that was mainly caused by anthropogenic activities. Also significant correlations existed between Cu, Co, and Zn concentrations. The maximum concentrations of Cu in shoots of Triticum vulgare, Medicago sativa, Amygdalus scoparia and Oryza sativa were 21.8, 21.2, 21, and 20.3 mg kg−1dry matter that were higher than the standard levels of Cu in plant dry matter. The maximum concentrations of Co in shoots of Medicago sativa,Vitis vinifera, Euphorbia spp., and Tamarix spp. were 12.7, 11.3, 10.3, and 10.2 mg kg−1 dry matter that were extremely higher than the standard levels of Co in plant dry matter, but the maximum concentration of Zn in shoot of Medicago sativa was 51.7 mg kg−1 dry matter that was near the normal range of this element in plants. Therefore, high concentrations of Cu and Co in these plants were caused by human activities and arise from soil and atmospheric pollution.

Chemiluminescence of Luminol for the Determination of Cobalt(II) Adsorbed on a Chitosan Membrane

In this work chemiluminescence (CL) of luminol was used for the determination of Co(II). This method is based on the fact that Co(II) catalyzes the CL reaction of luminol in the presence of H2O2. The optimization of the conditions of CL measurements in a liquid system (effect of luminol and H2O2 concentrations) is studied. This method has shown a remarkable sensitivity until 4 fg/L of Co(II) as detection limit. The linear range extends from 0.4 pg/L to 40 mu g/L of Co(II). The optimum conditions for the preparation of the chitosan membranes for the adsorption of cobalt ions were studied. The analytical characteristics of the membrane/liquid CL system are similar to those of the CL liquid system. The preconcentration of cobalt ions on the chitosan membrane presented here opens up possibilities for a number of biomedical applications for determination of Vitamin B-12 containing a cobalt ion in pharmaceuticals, human serum, egg yolk and fish tissue, and for environmental applications for the detection of cobalt in soils and river waters.

Cobalt in soils and plants of the Selenga River delta

The contents and distribution of cobalt in soils and plants of the Selenga River delta (the Buryat Republic) have been studied. It is shown that the cobalt content in the studied soils does not exceed the clarke value and is somewhat higher than the regional background value. Its distribution in the soil cover of the region is rather uniform. The concentration of cobalt in the aboveground phytomass is usually lower than its normal concentration in the vegetation of the world.

Bioaccumulation of cobalt in silkworm ( Bombyx mori L.) in relation to mulberry, soil and wastewater metal concentrations

The present study was planned to evaluate Co(II) toxicity in silkworm population. The soil was irrigated using synthetic wastewater to determine the effects of pH and initial cobalt concentration in its bioaccumulation in silkworm ( Bombyx mori L.) food chain. The amount of cobalt in wastewater, soil, mulberry and silkworm was determined by atomic absorption spectrophotometer (AAS) analysis. The obtained results clearly indicate that silkworm can be used as template to indicate local cobalt pollution as its body length, body weight and mortality rate was found to be strongly related to cobalt concentration. Higher the cobalt amount in mulberry leaves more the toxicity to silkworm population. At 400 mg/L Co concentration and pH 4 there was maximum deposition of Co in the soil from the synthetic effluent. However, in plants and silk worm the accumulation of Co was maximum at pH 4.5 at an initial Co concentration of 400 mg/L in the synthetic effluent. The maximum cobalt found in wastewater, soil, mulberry and silkworm was 400 ± 0.01, 273.5 ± 0.04, 42.85 ± 0.01, 36.62 ± 0.22 mg/kg, respectively.

Potential phytoavailability of anthropogenic cobalt in soils as measured by isotope dilution techniques

Isotope dilution is a useful technique to determine the potential phytoavailability of an element in soil. This method involves equilibrating an isotope with soil and then sampling the labile metal pool by analysis of the soil solution ( E value) or plants growing in the soil ( L value). The work reported here was conducted to evaluate the distribution coefficient ( K d), and the potential phytoavailability ( E value) of cobalt (Co) in eight soils subjected to the atmospheric deposition of anthropogenic Co. Multiple regression analyses demonstrated that the K d of isotopically exchangeable Co in these soils was best modelled with two parameters: soil pH and organic carbon (OC) content (log K d = 0.85(pH) + 1.1(logOC) − 5.0, R 2 = 0.94, p < 0.01). Cobalt E values ranged from 1.5 to 37% of total soil Co concentrations. No evidence was obtained to suggest that Co(III), if present, was isotopically exchangeable in these soils and it was concluded that the Co E values consisted solely of Co(II). Cobalt L values, measured with Triticum aestivum L. (46 days), of two of these soils (varying in soil pH, e.g. 5.0 and 7.2) were statistically ( p < 0.05) different to E values. However, when changes of bulk soil pH on Co E values were considered, the two values were statistically ( p < 0.05) similar indicating that processes affecting soil pH during plant growth can alter isotopically exchangeable concentrations of Co.

Distribution of Arsenic and Trace Metals in the Floodplain Agricultural Soil of Bangladesh

Arsenic contaminated groundwater of Bangladesh is one of the largest natural calamities of the world. Soil samples were collected from floodplain agricultural land of Faridpur and Dhamrai regions to estimate the concentration of arsenic and other trace metals (copper, nickel, zinc, chromium, cadmium, lead, selenium, cobalt, mercury, and manganese). Average arsenic in Faridpur soil was recorded more than three times higher than the world limit and nearly five times higher than that of Dhamrai. The average copper, chromium and cobalt both in Faridpur and Dhamrai agricultural soil were also higher than the Dutch and the world standards. Both Fardipur and Dhamrai soil contain low amount of selenium in comparison to world limit (0.7 mg kg(-1)). A poor correlation between manganese and arsenic was noticed in Faridpur. This may be played a subordinate role in the fixation of arsenic in soil. This study also reveals that the area which has arsenic and trace metal contaminated groundwater may also contain high level of arsenic and trace metals in the agricultural soil due to irrigation with contaminated groundwater.

Accumulation and implications of cadmium, cobalt and manganese in soils and vegetables irrigated with city effluent

AbstractBACKGROUND: In most parts of Pakistan, untreated city effluent is utilised for growing vegetables around large urban settlements such as Faisalabad. Farmers use it as a source of irrigation water and plant nutrients. However, its continuous use may have serious environmental implications, since it also contains heavy metals. In this study the Faisalabad city effluent was examined for irrigation quality and its impact on irrigated soils and vegetables.RESULTS: Irrigation hazard of the effluent was moderate (electrical conductivity (EC) 1.1–1.7 dS m−1, Sodium adsorption ratio (SAR) 5.9–17.4 mmol1/2 L−1/2, Residual sodium carbonate (RSC) 1.0–2.1 mmolc L−1) at site 1 and strong (EC 3.7–4.1 dS m−1, SAR 16.1–21.8 mmol1/2 L−1/2, RSC 4.0–9.1 mmolc L−1) at site 2. Mean concentrations of ammonium bicarbonate/diethylene triamine pentaacetic acid (AB/DTPA)‐extractable Cd, Co and Mn at upper soil depth (0.0–0.2 m) were respectively 0.080, 0.057 and 217.4 mg kg−1 at site 1 and 0.101, 0.076 and 164.1 mg kg−1 at site 2.CONCLUSION: The concentrations of Cd and Mn were above the permissible limits but that of Co was below the permissible limit for irrigation. The concentrations of Cd, Co and Mn tended to decrease with increasing soil depth. Accumulation of metals was higher in leaves irrespective of whether leaves were the edible or non‐edible component of shoots. Use of untreated city effluent for irrigation without risk assessment and management could be a serious hazard, impacting soil and crop quality and ultimately human health. Copyright © 2007 Society of Chemical Industry

Transformation of Fe, Mn, Co, and Ni compounds in humic podzols at different moisture

Incubation of humic podzol at soil moisture of 60 and 100% field capacity (FC) and after addition of peat and glucose increased the content of nickel and cobalt compounds in the water-soluble, exchangeable, organic matter-bound, and amorphous iron-bound fractions. At the same time, the content of elements bound to crystallized iron compounds decreased twofold and fourfold at 60 and 100% FC, respectively. The content of cobalt and nickel decreased in the residual fraction by 25 and 50%, respectively. The transformation of cobalt and nickel in soil is closely related to the transformation of iron and manganese compounds as well as to redox processes. The lowest pH and redox potential (RP) as well as the highest increase in the mobility of the elements was observed after soil incubation with glucose at 100% FC.

Seasonal Variation of Trace Elements in a Semiarid Veld Pasture

A two‐seasonal study was conducted to determine the trace mineral status of goats' grazing forages and soils in southern Punjab, Pakistan. Soil and forage samples were collected fortnightly for two seasons. Sampling period effects were found in soil copper, zinc, and selenium, and all forage minerals except selenium were affected by sampling times. Seasonal effects were observed in iron, manganese, and selenium for soils and in copper, iron, zinc, manganese, and selenium for forages. All soil mineral levels except cobalt and selenium were found to be above critical levels and likely to be adequate for normal growth of plants growing therein, whereas soil cobalt and selenium were severely deficient during both seasons. The levels of iron, zinc, cobalt, and selenium in soil were higher and copper and manganese were lower during winter than during summer. Forages contained marginal to deficient levels of cobalt during the winter, copper and selenium during the summer, and moderately deficient levels of iron and severely deficient levels of zinc, manganese, and cobalt during the summer. Forage copper, iron, zinc, manganese, and selenium during winter were found to be adequate for the requirements of ruminants. Consequently grazing animals at this location need continued mineral supplementation of these elements to prevent deficiency diseases and to support optimum animal productivity. Florida Agricultural Experiment Station Journal Series No. R‐10513.

Estimation of Reference Values for Cadmium, Cobalt, Chromium, Copper, Nickel, Lead, and Zinc in Brazilian Soils

The objectives of this study were 1) to recommend reference values (RVs) and tolerance limits (TLs) for representative Brazilian soils and 2) to propose a model to calculate natural contents of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) in a soil from the silt, clay, manganese (Mn), iron (Fe), and cation exchange capacity (CEC) values. A set of 256 soil samples was classified by similarity in seven groups, and the concentrations corresponding to the upper quarter of data collected were then calculated. These concentrations are proposed as RVs for Brazilian soils. Additionally, TLs were obtained for each group from the antilog expression (m+2s), where m=mean value and s=standard deviation of data transformed in log10. The classification functions of discriminant analysis proved to be suitable to allocate new samples in the established groups. Thus, it is possible to evaluate soils under anthropic activity and, by comparison with reference values, to be aware of pollution risks in a given area.

The status of cobalt in soil, plants and sheep in Shahrekord district, Iran

Summary Cobalt (Co) deficiency occurs in many parts of world especially in tropical and subtropical countries. Primary Co deficiency occurs only in places where the soil is deficient in Co. The type of soil and the presence of other substances like manganese and lime influence the absorption of Co (secondary Co deficiency). To determine the Co status in Shahrekord district, Iran, several important farms were selected and the Co concentration of 80 different soils (before cultivation) under cultivation of alfalfa, clover, barley and wheat and their cultivated plants (after full vegetative growing) were measured by atomic absorption spectroscopy. Moreover, blood samples were taken from 100 sheep fed the grown plants on those areas. The mean ± SD Co concentration in the soil of alfalfa, clover, barley and wheat farms were 0.14 ± 0.04, 0.16 ± 0.06, 0.10 ± 0.03 and 0.11 ± 0.05 mg/kg, respectively and the corresponding concentrations in plants were 1.32 ± 1.01, 2.2 ± 0.08, 1.2 ± 0.76 and 1.37 ± 0.88 mg/kg dry matter (DM), respectively. The mean ± SD Co concentration in sheep serum was 1.45 ± 0.41 µg/dl at various physiological conditions. Results indicated that in all studied areas, Co concentration in soil was lower than the normal range and primary Co deficiency was noticeable. On the other hand, Co concentration in different plants and ration was higher than animal demands, but serum Co was at marginal level and probably interfered with animal health. This study showed that the soils of lands under cultivation of clover and alfalfa and its related plants contained more Co than that of determined for barley (P<0.05). Furthermore, clover soil had higher amount of Co than wheat soil (P<0.05). There was a negative correlation between the amount of lead in soil of lands under cultivation of alfalfa and the concentration of Co in plants. Such a negative correlation was also detected between the amount of molybdenum and lead in soil and the concentration of Co in plants (P<0.05). Presence of some interfering factors in ration such as nitrogen (1.24 ± 0.3%), phosphorus (0.47 ± 0.18%), lead (2.87 ± 1.58 mg/kg DM) and molybdenum (0.1 ± 0.14 mg/kg DM) were negatively affected the uptake of Co and decreased serum Co concentration via secondary Co deficiency.

Evaluation of Distribution and Chemical Associations between Cobalt and Manganese in Soils by Continuous‐Flow Sequential Extraction

In this study, a strong association between cobalt (Co) and manganese (Mn) in different geochemical soil phases (fractions) was evaluated using a continuous‐flow sequential extraction technique employing a modified Tessier extraction scheme. With the flow system, detailed extraction profiles of Co and Mn in soils could be obtained by plotting concentrations of the elements extracted against extraction time (plots referred to as extractograms). Extractograms may be used as an indicator of whether the elements dissolving in the same extraction step are closely associated, or are merely extractable with the same reagent. From the soil samples studied, the coincidence of Co and Mn peaks seems to indicate a close association of these elements in the exchangeable, reducible, and oxidizable fractions. Analysis of flow extraction data suggested that the association between Co and Fe is not as strong as reported in previous studies based on the statistical analysis of batch fractionation data.

Solid phase extraction preconcentration of cobalt and nickel with 5,7-dichloroquinone-8-ol embedded styrene–ethylene glycol dimethacrylate polymer particles and determination by flame atomic absorption spectrometry (FAAS)

This article explores the synthesis of styrene–divinyl benzene (DVB)/ethylene glycol dimethacrylate (EGDMA) polymers embedded with quinoline-8-ol (Q) or its dihalo derivatives by thermal means in the presence and absence of 4-vinyl pyridine (VP). The above-synthesized polymers were found to enrich cobalt and nickel present in admixtures. Of these, 5,7-dichloroquinoline-8-ol (DCQ) embedded styrene–EGDMA polymer particles enrich cobalt and nickel quantitatively from dilute aqueous solutions within 5 min of preconcentration time. Styrene–EGDMA, DCQ embedded styrene–EGDMA particles obtained by bulk polymerization and cobalt/nickel bonded polymers were characterized by FTIR, thermogravimetric analysis (TGA), elemental analysis and surface area studies. The use of these polymer particles obtained by bulk polymerization for the solid phase extractive preconcentration of cobalt and nickel was investigated in detail and explores the possibility of employing this procedure for the analysis of cobalt and nickel in soil and sediment samples using a simple, low cost and readily available flame atomic absorption spectrometric instrument was explored.

Ecotoxicity of cobalt to the springtail Folsomia candida

Despite growing concern about the potential adverse effects of elevated cobalt concentrations in the environment, hardly any toxicity data are available for terrestrial invertebrates. Therefore, chronic toxicity of cobalt was assessed for the springtail Folsomia candida. The 28-day EC50 for the reproduction of F. candida was 1480 mg Co/kg dry wt in standard artificial soil (OECD) and 409 mg Co/kg dry wt in standard field soil (LUFA 2.2). The difference in toxicity can be explained by the higher pH and cation exchange capacity which decreased cobalt bioavailability in the OECD soil. When expressed as pore water concentrations, 28-day EC50s were similar: 159 mg Co/L in OECD and 174 mg Co/L in LUFA 2.2, which corresponded with calculated Co 2+ activities of 0.953 and 1.20 mmol/L, respectively. Although the presented data can be considered as a step forward in the assessment of the potential risk of cobalt in the terrestrial environment, more toxicity data for different species are needed to evaluate the environmental risk of cobalt in soils.

The availability of native and applied soil cobalt to ryegrass in relation to soil cobalt and manganese status and other soil properties

A glasshouse pot trial was conducted using 18 New Zealand grassland soils to assess the effects of soil manganese (Mn) and cobalt (Co) status, Co fertiliser and soil moisture conditions, on the plant availability of soil Co. The uptake of native and applied Co by ryegrass was measured, and attempts made to determine the main factors influencing plant Co concentrations. There were highly significant relationships between ryegrass Co concentrations and total soil Mn, and EDTA‐extractable and CaCl2‐extractable soil Mn; ryegrass Co concentrations decreasing in a curvilinear fashion with increasing soil Mn levels. Similar relationships were observed between ryegrass Co concentrations and Mn determined in individual soil fractions as determined using a sequential fractionation technique. It was therefore clearly demonstrated that soil Mn status plays a crucial role for soil Co availability. Soils with high Mn contents have a high probability of strong fixation of soil Co and showed negligible responses to Co fertiliser treatment. For the soils in this study, which had a large variation in Mn status, soil Co extractants were poor predictors of Co availability to plants. However, soil Co fractionation data suggests that Co in the organic‐bound fraction is probably one of the important sources of supplying Co in soils for plant uptake.

Chemical fractionation of heavy metals in soils around oil installations, Assam

The chemical fractionation of lead, cobalt, chromium, nickel, zinc, cadmium and copper in soils around Lakwa oil field, Assam, India was studied using a sequential extraction method. It is evident from the study that the residual fraction is the most important phase for the seven heavy metals under study. Among non-residual fractions metals are mostly associated with the Fe–Mn oxides fraction. The association of heavy metals with organic matter was observed in the following order: copper> cadmium> zinc> lead. The concentration of Pb in the carbonate fraction for both the seasons is higher compared with other metals, which may pose environmental problems due to its highly toxic nature. The comparatively low concentration of metals in the exchangeable fraction indicates low bioavailability. Correlations between physicochemical parameters and metal fractions of soil do not show consistent behaviour. The local mean values of metals when compared with the accepted values of normal abundance and geochemical background, indicates two to four fold increases in this area. However, the values are within the range of normal abundance. As well as from natural soil geochemical behaviour, anthropogenic influence might have a close bearing on the association of metals with the soil system in the studied area.

Predicting the risk of cobalt deprivation in grazing livestock from soil composition data.

The objective was to derive predictive equations for acetic acid-extractable cobalt (A-ECo) in soils so that extensive national databases for total (T) Co in soils and stream sediments could be converted to 'plant available' concentrations for the purpose of predicting risk of Co deficiency in grazing livestock. Data on the chemical and physical properties of 103 soils from 15 different parent materials and 54 soil series in England and Wales were used. Ranges for the mean values for parent materials were: TCo, 5.0-20.4 and A-ECo, 0.20-1.30 mg kg-1; percentage (P) A-ECo, 3.4-13.5; soil manganese (Mn) 268-1174 mg kgDM-1; pH, 3.7-8.0. There were significant effects of parent material on all parameters with Chalks, Old and New Red Sandstones particularly low in A-ECo. Multiple linear regression yielded the following equation for predicting A-ECo, which accounted for 56% of the variance with 12 outliers, including the lowest pH values, omitted: [figure: see text] REML was used on the complete, unbalanced, log-transformed data set to fit a Generalised Mixed Model with parent material as random effect and soil Mn and pH as fixed effects; the effect of parent material was no longer significant. It was concluded that A-ECo can be satisfactorily predicted for most soils in England and Wales from TCo, TMn and soil pH.

EFFECT OF COBALT ON CHLOROPHYLL AND CAROTENOID CONTENTS IN TOMATO PLANTS

ABSTRACT The effect of increased concentrations of cobalt (Co) (0, 50, 100, and 200 mg kg−1) and treatment with sewage sludge was investigated on the chlorophyllic pigments and carotenoids of tomato (Lycopersicon esculentum Mill cv. Ramy) plants, grown in a calcareous soil. Aerobically digested sewage sludge was applied at the rates of 2 and 4 g sewage sludge/100 g soil d.w., equivalent to 60 and 120 t ha−1. Treatments were compared with a non-fertilized control. Six leaf samples were taken at 27, 41, 55, 73, 94, and 105 days for each treatment and chlorophyll content was determined. Five leaf samples were taken at 35, 62, 75, 89, and 106 days to determine carotenoids content. Organic fertilization enhanced the levels of chlorophyll and carotenoids in tomato leaves. Cobalt induced a significant decrease in all the pigments analyzed, correlated with the increased presence of cobalt in soil. Also the negative effect of this pollutant seem to be enhanced by fertilization, probably due to a higher availability of Co with the increasing application of sewage sludge.

The impact of long-term cultivation and management history on the status and dynamics of cobalt in a savanna Alfisol in Nigeria

Summary The status of cobalt (Co) in savanna soils of Nigeria is largely unknown, and a long-term experiment including inorganic fertilizer (NPK) and farmyard manure (FYM) and uncultivated land provided information on the way management affected the dynamics of Co in the soil. Total Co increased with increasing depth, whereas readily extractable Co decreased. The mean concentration of Co (5.6–7.9 mg kg−1) was close to the mean value of 8 mg kg−1 reported for soils worldwide, whereas the concentration of extractable Co was less than that reported in most soils. Regression analysis indicated that total Fe predicted up to 78% of the soil Co. The potentially available Co correlated strongly with pedogenic or reducible Mn oxides extracted with dithionite–citrate–bicarbonate. Mass balance calculations showed that fertilization with either NPK or FYM caused losses of between 0.8 and 1.1 g Co m−2 after 50 years of cultivation against the uncultivated site as a reference. However, Co increased by 1.8 g m−2 in the soil receiving FYM + NPK, suggesting that the Co of the soil was best maintained under this management probably because of incidental additions of Co in the manures. Furthermore, the positive Co balance in the FYM + NPK plot was partly enhanced by its larger contents of clay, Fe and pedogenic Mn oxides than in either the FYM or NPK plots. Clay, Fe and pedogenic oxides served as Co sinks in this particular savanna soil.

Graphite furnace atomic absorption spectrometry used for determination of total, EDTA and acetic acid extractable chromium and cobalt in soils.

Methods for determination of both the total and extractable content of Cr and Co in soil samples were investigated. For the total content of metal, ultrasonic slurry sampling graphite furnace atomic absorption spectrometry was used and compared with conventional analyses after microwave digestion. The influence of grinding, leaching and homogeneity for slurry sampling was also examined. The concentration of the elements in the analyzed materials were in the range: 50 microg g(-1)-0.4% for Cr and 8-14 microg g(-1) for Co. Relative standard deviations (slurry sampling) were in the range 3%-12% for Cr and 0.3%-6% for Co determinations. The detection limit and characteristic mass (peak-area measurements) for Co were 0.14 microg g(-1) and 12.6 pg, respectively. For Cr less sensitive wavelengths were used. Excellent agreement with certified reference material was found for total Cr and Co using slurry sampling. EDTA and acetic acid extractions were performed, using protocols given by the Measurement and Testing Programme of the European Commission. The percentages extracted for the different soil samples were 0.3-1.0 for Cr and 2.5-24 for Co. To validate the accuracy of the extractable Cr, CRM 483 Sewage sludge amended soil was analyzed. The values found were 37% and 32% higher than the certified value for EDTA and acetic acid extractable Cr, respectively. The precision for extractable concentration of Cr and Co was about 6% or less. External calibration with aqueous standards, matched to contain the same reagents as the samples, was employed.