Total Content Of Co Research Articles

Heavy Metals in Sediments of Subarctic Meromictic Lakes of the White Sea as Possible Tracers of Environmental Changes

Meromictic lakes of the marine coast, quite widely distributed in the northern hemisphere, are the result of climate changes and glacier retreat. The bottom sediments of these lakes serve as a geological chronicle of the history of marine basin’s development with the geochemical occurrence forms of elements indicate various processes of their accumulation. This paper presents research results concerning the occurrence of forms of heavy metals in lake sediments along the coast of the White Sea. These results are based on a sequential seven step leaching procedure, followed by ICP-MS analysis and subsequent statistical data processing. To determine differences among the examined geochemical parameters, Pearson’s correlation analysis and Ward’s cluster analysis were utilized. The total content of Cr, Mn, Fe, Co, Ni, Zn, V, and Pb in the sediments did not exhibit significant differences based on their degree of isolation from the sea. The major contribution to deposition of these metals in sediments of the meromictic lakes studied is the residual form, encompassing the mineral matrix of the sediment. At the same time, the elevation of mobile forms for all the metals examined corresponds to an increase in the isolation of lakes from the White Sea. In the meromictic lake sediments, concentrations of Cu, Mo, and U demonstrated significant increases in forms tightly bound to organic matter, while Cd exhibited an association with Fe-Mn oxyhydroxides. Notably, a significant difference in the occurrence forms of Cu, Cd, Mo, and U was evident in the reduced sediments of meromictic lakes when compared to those of open sea bays. The meromictic lakes along the White Sea coast, positioned at various stages of isolation, hold promise for investigating the migration of metals in response to environmental changes.

Potentially toxic elements in soil and air along an altitudinal gradient in Tatra National Park

With a growing number of tourists, national parks are facing high pressure in terms of production and spreading the potentially toxic elements (PTEs). Car parks, roads or civil amenities have become a source of PTEs, which are spreading not only in their immediate vicinity, but can contaminate much wider surroundings. Total content of Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb and Zn was determined in soil samples and, also in mosses and lichen samples, which were used as bioindication method for air pollution monitoring. Soil pollution was evaluated by contamination factor (Cf), degree of contamination (Cd) and the pollution load index (PLI). The impact of pollution on selected soil characteristics (soil enzymes, soil respiration, total nitrogen, organic carbon, soil pH) was also evaluated. Content of PTEs in moss and lichen samples was expressed by relative accumulation factor values (RAF).The most serious soil pollution was recorded at the first (lowest in terms of altitude) sampling point, but soil contamination reached significant values also at higher altitudes. All evaluated soil properties showed decreasing tendency under the soil pollution, with exception of soil pH, which showed positive correlation with PTEs. The ability of mosses and lichen to accumulate pollution in their insoles varied depending on the toxic element. High levels of PTEs have also been captured at higher altitudes due to their ability to spread, transport and accumulate in the environment.

Cycling and status of cobalt in some forest types

Abstract The concentrations of Co were determined in the hydrological cycle (in maquis and fir forests), litterfall and soils in maquis, oak, beech and fir forests. The concentrations in the hydrological cycle were characterized by high variability. The concentrations in soil solution were much higher than those in the bulk deposition and throughfall. The contribution of the earth’s’ crust in the bulk deposition enrichment with Co was not high but some minor quantities of Co can be considered to be transported in long distances. The concentrations of Co in litterfall were high in the fraction composed of lichens, flowers and mosses, especially in the fir forest. The total content of Co was significantly higher in the soils derived from mica schist than those in the flysch. The residence time of Co in the forest floor was rather long. This is an indication that weathering in the mineral layers plays an important role in providing Co for plant uptake.

Metal speciation in sludges: a tool to evaluate risks of land application and to track heavy metal contamination in sewage network.

The agricultural spreading of dehydrated sewage sludge from urban sewage treatment plants is economically profitable provided that the soil agronomic quality and the absence of contamination, in particular of heavy metals, are maintained. We evaluated the variability of sludge between five treatment plants in northern Algeria. We determined parameters that account for their agronomic quality and total content of Ag, Cd, Co, Cr, Cu, Ni, Pb, Ti and Zn. The speciation of metals, which determines their bioavailability, was characterized by sequential extraction into five fractions: easily exchangeable, acid-soluble, bound to carbonates and Fe-sulphides, bound to Fe-Mn oxides, bound to organic matter or sulphides, residual. All the sludges analysed showed satisfactory properties for plant growth. High total Ni contents for three of the sludges indicated that they were not landfillable under French or Chinese regulations. Ni, however, was contained in poorly bioavailable fractions and therefore presented a low risk to soils. In contrast, the total Cu was lower than the regulatory limit values, but mainly contained in very bioavailable fractions whose accumulation over time could reach toxic levels for plants over a period of 3 to 11years depending on the sludges. These results showed that regulations are not adapted and must take into account the bioavailability with regard to the characteristics of the soils on which to spread. The speciation of metals in the sludge has also, on the one hand, made it possible to identify the zone of the sewerage network in which the sources of contamination must be sought and, on the other hand, has given indications on the possible nature of these sources.

Investigation of characteristics of gas and coke residue for the regime of quasi- and non-stationary steam gasification of coal in a fluidized bed: Part 1

The steam oxygen-free gasification allows deep processing of coal and obtaining gas with high contents of H2 and CO. The design of dual fluidized bed gasifiers (DFB) is considered promising. There are insufficient experimental data on the steam gasification process in DFB for more accurate mathematical modeling. The paper presents the experimental results in dynamics of the quasi-stationary and non-stationary gasification of two types of coals in a laboratory gasifier. It has been established that when using superheated steam for preliminary and main gasification process, it is possible to obtain a gas with a total content of H2 and CO of more than 75% vol, maximum cold gas efficiency 87%. The conditions for the expedient use of two chambers for gasification of coals of different degrees of metamorphism are identified. The gasification regimes that will increase H2 and CO formation in DFB are determined. This research substantiate the necessarily to use only steam in DFB for improving the synthesis gas quality.

Determination of the Elements Composition in Sempervivum tectorum L. from Bulgaria

Sempervivumtectorum L. is an evergreen plant with fleshy blue-green leaves forming a rosette. The plant is well-known in alternative medicine and has been used for thousands of years. Traditionally for medicinal purposes, the plant is used as a juice obtained by simple squeezing of fresh plants leaves. The total content of Ca, K, Na, Mg, Mn, Fe, Zn, Cu, Co, Al, V, Cr, Ni, Mo, Ba, Pb, Cd, Hg, As, and Tl in plant leaves of Sempervivum tectorum L. sampled from different habitats in Bulgaria was determined after microwave digestion and measurements by inductively coupled plasma mass spectrometry and flame atomic absorption spectrometry. Furthermore, the bioavailable fraction of essential elements Ca, Mg, Fe, Mn, and Zn was defined after extraction with a hydrochloric acid solution, mimicking stomach juice. The total element content showed a high bioavailability of essential human health elements, such as Ca, Mg, Fe, and Zn. Additionally, essential and toxic elements concentrations were quantified in a fresh juice, obtained by squeezing from plant leaves, as most frequently used in folk medicine. The results obtained demonstrated high concentrations of K, Mg, Ca, Zn, and Cu, which could be accepted as an explanation and a further confirmation of the anti-inflammatory action of this plant.

Nutrient and Popping Characteristics of Wyoming-Grown Peruvian Popping Beans

Describe nutrient and popping characteristics of nuña popping beans, a novel food choice for consumers. American consumers fall short of dietary guidelines for fiber. Beans are a rich source of protein and fiber, however, less than 14% of adults include beans/legumes in their daily diets. Nuña beans (Phaseolus vulgaris L.), a class of common beans originated in South America and cultivated for growth in North America, possess unique characteristics including flavor profile, popping ability, and nutrient content that may appeal to consumers. The purpose of this study was to evaluate Wyoming-grown popping beans to 1) determine nutrient characteristics and 2) assess popping percentage and shelf stability. Crude protein concentration was determined for mature seed of five lines grown in Wyoming utilizing the Dumas method for nitrogen quantification. Total fatty acid content and a fatty acid profile for one line [CO49957] was determined by gas-liquid chromatography. Popping percentage was assessed by heating beans in canola oil in a cast iron pan to induce popping. The impact of storage time on popping percentage was evaluated on CO 49957 at month 6 and 12 after harvest. Crude protein concentration averaged 19.9% and did not significantly differ among the five lines. Total fatty acid content of CO 49957 averaged 1.55 g/100g. Average fatty acid profile was primarily comprised of α-linolenic acid (38.9%), linoleic acid (24.7%), and palmitic acid (19.4%). Popping percentage was 90% (baseline), 100% (6 months), and 87% (12 months). Popping beans can provide consumers a significant source of plant-based protein and fiber while maintaining adequate levels of popping percentage with prolonged storage.

Lability and bioavailability of Co, Fe, Pb, U and Zn in a uranium mining restoration site using DGT and phytoscreening.

Mine restoration is a long and ongoing process, requiring careful management, which must be informed by site-specific, geochemical risk assessment. Paired topsoil and tree core samples from 4 sites within the uranium mining complex of INB Caldas in Minas Gerais (Brazil) were collected. Soil samples were analysed for their total content of Co, Fe, Pb, U and Zn by XRF, and subsequently, the potential environmental bioavailability of these metals were investigated by DGT and pore water analysis. In addition, results were compared with metal concentrations obtained by Tree Coring from the forest vegetation. In all sampling areas, mean total concentrations of U (Ctot. = 100.5 ± 66.5 to 129.6 ± 57.1 mg kg-1), Pb (Ctot. = 30.8 ± 12.7 to 90.8 ± 90.8 mg kg-1), Zn (Ctot. = 91.5 ± 24.7 to 99.6 ± 10.3 mg kg-1) and Co (Ctot. = 73.8 ± 25.5 to 119.7 ± 26.4 mg kg-1) in soils exceeded respective quality reference values. Study results suggest that AMD caused the increase of labile concentrations of Zn in affected soils. The high lability of the elements Pb (R = 62 ± 34 to 81 ± 29%), U (R = 57 ± 20 to 77 ± 28%) and Zn (R = 21 ± 25 to 34 ± 31%) in soils together with high bioconcentration factors found in wood samples for Pb (BCF = 0.0004 ± 0.0003 to 0.0026 ± 0.0033) and Zn (BCF = 0.012 ± 0.013 to 0.025 ± 0.021) indicated a high toxic potential of these elements to the biota in the soils of the study site. The combination of pore water and DGT analysis with Tree Coring showed to be a useful approach to specify the risk of metal polluted soils. However, the comparison of the results from DGT and Tree Coring could not predict the uptake of metals into the xylems of the sampled tree individuals.

Influences of controlled microwave field radiation on pore structure, surface chemistry and adsorption capability of gas-bearing shales

Aiming to explore the feasibility of using microwave field radiation to produce shale gas via temperature swing. The heating behaviors and alterations in physicochemical properties and adsorption capability of gas-bearing shales under the controlled microwave field are preliminarily investigated. Results indicate that the shales can significantly absorb microwave energy. The bulk temperature of shales increases with the duration of microwave radiation. The heating behaviors of shales under the controlled microwave field are probably associated with pyrite and marcasite contained in shales, which greatly determine the complex permittivity and thermal conductivity of shales. Next, the microwave radiation decreases the adsorption pores with pore width below 10 nm, and fractal dimensions of pore surface and pore structure of the shales determined from the Neimark model and the FHH model, while increases the amount of meso- and macropores with pore width above 10 nm, MIP total pore volume and porosity of shales. These alterations in pore structure promote desorption and migration of shale gas within reservoirs. Furthermore, the microwave radiation changes the surface chemistry property of shales. The FTIR analysis reveals that the total content of CO and COOH of shales grows after the microwave radiation, whereas the aromaticity decreases. The alterations in both oxygenic functional groups and aromaticity are prone to promote shale gas desorption from shale matrix by weakening the intermolecular force between shale gas and shale matrix. Finally, the microwave radiation decreases the maximum CH4 adsorption capacity of the shales, the decreasing amplitude of which is 12.70–47.83%. In conclusion, the aforementioned heating behaviors and alterations in physicochemical property and adsorption capability of shales under the controlled microwave field imply that microwave radiation is an alternative option to enhance shale gas production.

Toxicological effects of different-sized Co-Fe (CoFe2O4) nanoparticles on Lepidium sativum L.: towards better understanding of nanophytotoxicity.

Due to their widespread therapeutic and agricultural applicability and usefulness in removing metals and metalloids from water, cobalt ferrite nanoparticles (NPs) are currently receiving increasing attention from researchers. However, their potential phytotoxicity is still poorly understood. Thus, the aim of the current study was to assess the effects of synthesized cobalt ferrite (CoFe2O4) NPs on biological (morphological, physiological, and biochemical) parameters of edible plant garden-cress (Lepidium sativum L.), depending on particle size and concentrations. In this study, physical characteristics of cobalt ferrite NPs were determined. Increased total content of Co and Fe in L. sativum tissues and their transfer from roots to above-ground parts of seedlings, which depended on the size of NP (15 < 5 < 1.65 nm), indicated that plants had been exposed to Co ferrite NPs. The relative growth of roots, biomass of roots and above-ground parts of seedlings, amounts of chlorophylls a and b, carotenoids, and malondialdehyde (MDA) were determined. The dependence of the tested garden-cress parameters on the size and concentrations of NPs was revealed. Our data showed that the content of MDA in test plants in some cases increased up to 2.5 folds in comparison to control. The increase of the content of chlorophyll b pigment and MDA in test plants is an appropriate indicator of the impact of cobalt ferrite NPs. The findings of our study into toxicological effects of Co-Fe (CoFe2O4) NPs on L. sativum are expected to deepen the knowledge of the nanophytotoxicity of ferromagnetic NPs and their potential application in biomedicine and agriculture.

Microwave-assisted catalytic pyrolysis of waste printed circuit boards, and migration and distribution of bromine

Microwave-assisted pyrolysis (MAP) of waste printed circuit boards (WPCB) was performed to investigate the characteristics of pyrolysis product and Br fixation. Pyrolysis conversion increased with increasing temperature, reaching 93.3 % at 650 °C. However, increasing heating time did not exhibit remarkable influence on pyrolysis conversion. At 350 °C, phenols were main compounds in the oil accounting for 91.15 %. As the temperature increased to 650 °C, polycyclic aromatic hydrocarbons and monocyclic aromatic hydrocarbons (except phenols) increased to 20.55 % and 19.03 %, respectively. Meanwhile, the total content of CO2, CO, CH4 and H2 in the non-condensable gases increased significantly. Addition of ZSM-5 and kaolin promoted the recombination reaction of pyrolysis products, increased the relative percentage of monocyclic aromatic hydrocarbons (except phenols) and C11-C20 compounds in the oil, and reduced non-condensable gases. The oxygen bomb-ion chromatography was used to evaluate the Br content of pyrolysis residues. Higher pyrolysis temperature enhanced transfer of Br to pyrolysis gas. K2CO3, Na2CO3 and NaOH reacted with hydrogen bromide to generate KBr and NaBr, which significantly improved the Br fixation efficiency of pyrolysis residues (i.e. from 29.11%–99.80%, 96.39 % and 86.69 %, respectively) and reduced Br content in pyrolysis gas.

Carbon Monoxide Variations in the Antarctic Atmosphere from Ground-Based and Satellite Measurement Data

The results of systematic (2003–2017) measurements of the total content and height-averaged relative volume concentration of CO at st. Novolazarevskaya with a spectrometer with a resolution of 0.2 cm–1 are presented. The inverse problem of determining the total content of CO as well as interfering gases (H2O and N2O) was solved using the SFIT4 software package. A data analysis indicated that during the measurements the average total CO content at st. Novolazarevskaya was (8 ± 2) 1017 molecules/cm2 and the height-averaged volume concentration was (37 ± 8) ppb. The resulting data were compared with variations in the total CO content at st. Arrival-Heights, MOPITT satellite data, and CO surface concentrations at st. Syowa. The maximum and minimum values of CO were observed in September and January–February, respectively. For all the data series considered, the trends are insignificant; in this case, an increased CO content was observed in 2010, and an increasing trend of the minimum values of CO was observed in recent years (2014–2017). Both stations (Novolazarevskaya and Arrival-Heights) are characterized by an excess of satellite data over ground-based measurement data (19% and 14%, respectively); here, a seasonal dependence of the deviation was observed with minimal deviations in December–January. Data of surface measurements of the total content at st. Novolazarevskaya and Arrival-Heights are rather well consistent, and the average deviation since 2010 was 2.4%. The average concentration of CO at st. Syowa (51 ppb) is higher than the height-averaged concentration at st. Novolazarevskaya. According to spectral, wavelet, and composite analyzes, all data series considered include oscillations in the range of 6–45 months with almost identical periods and phase relationships.

Conversion of Liquefied Hydrocarbon Gases on Commercial Nickel Catalysts

The two-step conversion of industrial liquefied hydrocarbon gases (LHG) on NIAP-07-01 (NKM-1) and NIAP-03-01 catalysts for the production of hydrogen-containing gases was investigated. The experiments were carried out in flow reactors with a fixed catalyst bed at a pressure of 0.1 MPa under the following conditions: temperature 350–450 °C, gas hourly space velocity (GHSV) 1000–3000 h–1, steam-gas ratio 4 : 1–8 : 1 (pre-reforming); and temperature 700 °C, GHSV 2000 h–1, air-gas ratio 1.2 : 1 (steam-air reforming). Under the studied conditions, the concentrations of components of the converted gas correspond to the equilibrium values calculated within the Peng-Robinson model. The conversion of methane homologs in the pre-reforming step was found to be virtually 100 %; therewith, the methane concentration reached 32–54 %, and that of hydrogen, 24–47 %. To prevent the formation of elemental carbon (carbonization), pre-reforming of hydrocarbon gases with a high methane equivalent should be performed at H2O : C &gt; 2. In the two-step reforming, the yield of hydrogen-containing gas reaches 15.6 m3 from 1 m3of the initial LHG with the hydrogen content 41.81 %, and the total content of CO and H2exceeds 52 %.

Preference of Co over Al for substitution of Fe in goethite (α-FeOOH) structure: Mechanism revealed from EXAFS, XPS, DFT and linear free energy correlation model

Goethite is the most stable iron hydroxide mineral in geological environments, and it is usually crystallized with more than one type of substituent. However, the synergetic or antagonistic effects of coexisting cations on substitution for lattice Fe in gothite are unclear. In this study, a series of Co-, Al-, and Co + Al co-substituted goethite samples were synthesized at room temperature and then investigated by powder XRD, X-ray photoelectron spectroscopy (XPS), X-ray absorption fine structure spectroscopy (XAFS), density function theory (DFT) calculations, and acid dissolution experiments. All the obtained samples were pure goethite, except the one with a high total content of Co + Al that contained a portion of 2-line ferrihydrite. Lattice parameter a of Co + Al co-substituted goethite was linearly decreased with the final Co content, lattice parameter b and calculated crystal density had the best negatively linear relationships with Al content while lattice parameter c, cell volume, average edge-sharing Fe − Me (Me = Fe, Al, and Co) distances along c⁎ and b⁎ axis (E′ and E) and average corner-sharing Fe − Me (DC) distances had the best linear correlations with the total contents of Co + Al. Aluminum and Co were found to be evenly distributed in goethite structure, and both reduced the mineral particle size. Co coexisted in a mixed valance of +2 and +3, and the proportion of Co3+ increased with the increase of Co content in Co-substituted goethite owing to relatively high electric potential energy and decreased with the increase of coexisting Al3+ content in Co + Al co-substituted goethites because of relatively low alkalinity in local environments around Co2+. Incorporation of Co greatly promoted the mineral dissolution in 2 M HCl solution at 298 K. Fe K-edge EXAFS analysis indicated almost constant local order around Fe in these samples. Coexisting Al had almost no effect on Co incorporation into goethite structure but Co suppressed Al substitution for lattice Fe. This preference of Co over Al to substitute for Fe was explained by the predicted partition coefficients (Kd) of common trivalent substituents in goethite by using the linear free energy relationship. It highlights the necessity to take into consideration not only the substituent physical properties (size and charge) but also their chemical properties (chemical bonding energy and chemical potential). These results enhanced our understanding of the incorporation of exotic cations into the iron oxide structures and the mutual effects of coexisting cations on substitution for lattice Fe.

Variations of carbon monoxide in the atmosphere of Antarctica according to ground-based and satellite measurements

The results of systematic (2003–2017) measurements of the total content and the volume mixing ratio of CO at Novolazarevskaya station with a spectrometer with a resolution of 0.2 cm– 1 are presented. The inverse problem of determining the total CO content, as well as interfering gases (H2O and N2O), was solved using the SFIT4 software package. Data analysis showed that over the measurement period the average total CO content at Novolazarevskaya amounted to (8 ± 2) 1017 molec/cm2, and the average volume mixing ratio amounted to (37 ± 8) ppb. The obtained data are compared with variations in the total content of CO in Arrival-Heights station, with MOPITT satellite data, as well as with surface values of CO concentration at Syova station. The maximum values of CO are observed in September, the minimum — in January–February. For all the considered series, the trends are insignificant, while there are periods of increased CO content (2010). In recent years (2014–2017) there is a tendency towards an increase in the minimum values of CO. For Novolazarevskaya and Arrival-Heights satellite data are characterized by the excess of over ground data, amounting to 19% and 14%, respectively, while there is a seasonal dependence of the deviation with the minimum in December–January. Surface measurements of the total CO content are in fairly good agreement at Novolazarevskaya and Arrival-Heights, and since 2010 the average deviation is 2.4%. The average value of the concentration of CO on Syova 51 ppb is higher than the average volume mixing ratio at Novolazarevskaya. According to the spectral, wavelet and composite analyzes, in all the considered series there are oscillations in the range of 6–45 months with closely coinciding periods and phases.

Heavy metal content and mobility in urban soils of public playgrounds and sport facility areas, Poland

Among the threats to air, soil, and water posed by urbanization, heavy metals appear particularly hazardous. Playgrounds and sport facilities are unique urban places, widely used by children and youth. The aim of this research was to evaluate heavy metal pollution in urban soils, identify relationships among topsoil metal distributions, and assess related health risks in two Polish cities – Warsaw and Bydgoszcz. According to the Regulation of the Polish Minister of the Environment guidelines for total content of Pb, Cu, Zn, Ni, Cd and Co our study sites were classified as uncontaminated. Applied Geoaccumulation Index (Igeo; Müller, 1969) largely confirmed this classification, with only two of the investigated Warsaw areas “moderately polluted” with Pb. Generally, only Pb and Zn concentrations exceeded reference background levels for Polish soils. The highest concentrations of Pb and Zn were found in the city centers, the oldest areas where pollution risk is potentially the highest.Metal mobility and solubility were mainly correlated with total content, indicating potential risk from lead and zinc. At some sites in Warsaw, where mean Pb concentration was 87.25 mg kg−1 and Zn 207.25 mg kg−1, health risks from ingestion and inhalation seemed significant, particularly for children. In Bydgoszcz use of the studied playgrounds and sport facility areas did not pose a risk to human health.Finally, the study (especially in Warsaw) indicates the need for continued monitoring and suggests lowering permissible limits of these metals in soils, especially in recreational areas, may decrease childrens' exposure risk to these pollutants.

The Influence of Seabirds on the Concentration of Selected Heavy Metals in Organic Soil on the Bellsund Coast, Western Spitsbergen

ABSTRACTSeabirds are an important factor affecting the chemical properties of the arctic soil environment. The objective of this work was to study the differences in content and distribution of heavy metals in organic soils resulting from the differential influence of seabirds. Studies were conducted in two stations in the southwest part of Spitsbergen—the first without the influence of seabirds and the second directly affected by an avian colony. Basic properties of soils as well as total content of Ca, Na, Mg, K, Fe, Al, Cu, Zn, Ni, Mn, Pb, Cd, Co, and Cr were determined. Reference was made to the previously published contents of different forms of phosphorus (P) for these locations. The studies showed that Zn, Mn, Cu, and Cd contents were higher in the soils that had been in the vicinity of the seabird colony. High statistically positive correlations of Cd, Cu, and Zn were noted with particular P forms. In the case of Pb, Cr, Co, and Ni content, the seabird influence was not dominant; probably other factors were more relevant (the processes of weathering, denudation, leaching, and atmospheric pollutants transported in the form of dust or gases). Clear segregation was observed of individual positions conditioned by selected soil features and by heavy metals content.

Risk of Chickpea (Cicer Arietinum L.) Contamination by Risk Metals from the Soil of Iraq

The aim was to evaluate the influence of the grown locality on risky metal intake from the soil to the chickpea seeds. The research was realised in three different localities of Iraq (Harer, Erbil, Ankawa) using the same chicpea cultivar. In all soil samples the determined total content of Co, Ni, Cr, and Cd exceeded the limit values (by 45% - 87%, 196% - 302%, 57% - 132% and 500% - 810%, respectively). In one locality (Harer) also the Cu content by 2% exceeded maximal allowed value given by the legislative. In all sample sites also the maximal available soil content of mobile Pb forms was by 5% - 265% exceeded. Despite of extremely high soil contents of Co, Ni, and Cr the investigated chickpea seeds are from the point of these risky metal contamination safe. All determined values of heavy metal contents are lower than hygienic limits. Only Cd and Pb amounts in seeds of chickpea from Iraq exceeded the limit value given by legislative. Based on our results we could suppose that chickpea can be risky food if it is grown in the soil with enhanced amounts of Pb and Cd.

Risk of Chickpea (Cicer Arietinum L.) Contamination by Risk Metals from the Soil of Iraq

The aim was to evaluate the influence of the grown locality on risky metal intake from the soil to the chickpea seeds. The research was realised in three different localities of Iraq (Harer, Erbil, Ankawa) using the same chicpea cultivar. In all soil samples the determined total content of Co, Ni, Cr, and Cd exceeded the limit values (by 45% - 87%, 196% - 302%, 57% - 132% and 500% - 810%, respectively). In one locality (Harer) also the Cu content by 2% exceeded maximal allowed value given by the legislative. In all sample sites also the maximal available soil content of mobile Pb forms was by 5% - 265% exceeded. Despite of extremely high soil contents of Co, Ni, and Cr the investigated chickpea seeds are from the point of these risky metal contamination safe. All determined values of heavy metal contents are lower than hygienic limits. Only Cd and Pb amounts in seeds of chickpea from Iraq exceeded the limit value given by legislative. Based on our results we could suppose that chickpea can be risky food if it is grown in the soil with enhanced amounts of Pb and Cd.

Fast determination of trace elements in organic fertilizers using a cup-horn reactor for ultrasound-assisted extraction and fast sequential flame atomic absorption spectrometry

A fast and accurate method based on ultrasound-assisted extraction in a cup-horn sonoreactor was developed to determine the total content of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in organic fertilizers by fast sequential flame atomic absorption spectrometry (FS FAAS). Multivariate optimization was used to establish the optimal conditions for the extraction procedure. An aliquot containing approximately 120 mg of the sample was added to a 500 µL volume of an acid mixture (HNO3/HCl/HF, 5:3:3, v/v/v). After a few minutes, 500 µL of deionized water was added and eight samples were simultaneously sonicated for 10 min at 50% amplitude, allowing a sample throughput of 32 extractions per hour. The performance of the method was evaluated with a certified reference material of sewage sludge (CRM 029). The precision, expressed as the relative standard deviation, ranged from 0.58% to 5.6%. The recoveries of analytes were found to 100%, 109%, 96%, 92%, 101%, 104% and 102% for Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. The linearity, limit of detection and limit of quantification were calculated and the values obtained were adequate for the quality control of organic fertilizers. The method was applied to the analysis of several commercial organic fertilizers and organic wastes used as fertilizers, and the results were compared with those obtained using the microwave digestion procedure. A good agreement was found between the results obtained by microwave and ultrasound procedures with recoveries ranging from 80.4% to 117%. Two organic waste samples were not in accordance with the Brazilian legislation regarding the acceptable levels of contaminants.