Total Cobalt Research Articles

Moderately hazardous microelements in the soils of saline agrolandscapes of the Baraba plain

When developing adaptive-landscape farming systems, special attention is paid to the study of the ecological, toxicological and sanitary-hygienic state of the territory used. This is especially important for saline agro-landscapes, which are widespread in the Barabinskaya plain (Baraba). The studies were conducted in the northeastern part of the Baraba within the Novosibirsk Region. The soils of the eluvial (meadow-chernozem), transit (chernozem-meadow), and accumulative (deep solonetz) zones of the catena were studied. The soils differed in physicochemical properties and microelement composition. In the soil profile from the eluvial to accumulative zone, alkalinity increased, humus content decreased, and the granulometric composition changed. These indicators affect the microelement composition. The content of moderately hazardous trace elements (hazard class 2): chromium (Cr), nickel (Ni), cobalt (Co) and molybdenum (Mo) were determined. It was found that the maximum content of total chromium falls on the profile of meadow-chernozem soil in the eluvial position. In the arable horizon there is less than 0.00001 mg/kg of mobile chromium, which does not fall within the detection range of the device. Some movement of mobile forms of chromium from the eluvial to accumulative position was noted. The maximum content of total nickel and cobalt was found in the profile of meadowchernozem soil, but it is in amounts well below the LOC. The total content of nickel and cobalt varies insignificantly across the soil profile, indicating their low mobility. The total content of Mo in soils is within the clarke range and is approximately the same over the entire depth. It was found that the content of moderately hazardous trace elements of nickel and cobalt in the soils of saline agro-landscapes of Baraba by catena is below the LOC and cannot be a hazard from the ecological-toxicological point of view. The content of total chromium and molybdenum is on the verge of the LOC and therefore, in certain cases, tension in the ecological and toxicological situation of the territory may arise. This should be taken into account in the agricultural use of saline agrolandscapes.

Определение кобальта в образцах плазмы крови методом масс-спектрометрии с индуктивно-связанной плазмой после перорального приема содержащих кобальт биологически активных добавок к пище

Salts of inorganic cobalt (Со) prevent the degradation of the alpha subunit of the hypoxia-inducible factor (HIF), imitating the state of hypoxia in the body and increasing the production of the endogenous hormone erythropoietin (EPO), and are used as doping substances that increase blood oxygen capacity and endurance, which give competitive advantages in sports. Currently, a large number of dietary supplements, including Co-containing ones, are offered on free sale. Their uncontrolled intake can affect not only the professional career of athletes, but also their health, due to the fact that this trace element and its salts are the strongest inorganic poisons and carcinogens. Despite this, their availability on the pharmaceutical market, a noticeable effect of erythropoiesis stimulation and a convenient oral form of administration lead to the need for their detection in modern doping control. The purpose of this research was to develop an approach to differentiate cobalt from vitamin B12, present in the body in its natural state, from the intake of cobalt salts by quantifying and comparing blood levels of vitamin B12 and total cobalt. Methods. The study involved 9 healthy volunteers (women and men) aged 25 to 45 years, leading an active lifestyle. Three of them took 2500 μg/day of cobalamin for 20 days (comparison group), three - dietary supplement containing cobalt asparaginate (100 μg/day in terms of pure cobalt), and the rest - dietary supplements with cobalt sulfate heptahydrate (100 μg/day in terms of pure cobalt) (administration groups) at the same time after meals. Blood samples were taken at baseline and on days 5, 9, 14 and 20. The concentrations of total cobalt in blood plasma samples of volunteers were measured by inductively coupled plasma mass-spectrometry (ICP-MS), the levels of cobalamin were determined on a Cobas 6000 immunochemical analyzer using the Elecsys Vitamin B12 II Assay ELISA kits. Results. It was found that oral intake of of cobalamin at a therapeutic dose significantly exceeding the recommended daily intake (3 μg), there was a regular slight increase in the blood concentration of total cobalt (1.1 times). At the same time intake of dietary supplements containing cobalt in the form of sulfate or asparaginate (about 100 μg per day in terms of pure cobalt) was accompanied by 4-6.7 fold increase in the concentration of total cobalt while unchanged vitamin B12 plasma concentration was observed. The detection of such changes can reliably indicate the use of prohibited salts and, of course, will be in demand for anti-doping control. Conclusion. Long-term monitoring of vitamin B12 and total cobalt levels, similar to hematological module of the Athlete Biological Passport program, will unambiguously detect possible abuse of cobalt salts and can be an additional evidence of the presence of these doping substances to other analytical methods, such as a combination of liquid chromatography and ICP-MS (LC-ICP-MS).

Geochemical Assessment of some water Resources in Obio Akpor and Port Harcourt, Niger Delta Basin, Nigeria

Assessment of heavy metal concentrations in water resources within Obio-Akpor and Port Harcourt local government area of Rivers State in Niger Delta, Nigeria was carried out. Five water samples were obtained from Station 1 surface water, four water samples were acquired from Station 2 surface water and three groundwater samples were obtained from Station 3. The physiochemical parameters analyzed were pH, Temperature, Electrical conductivity, Total dissolved solids and Turbidity while the heavy metals analyzed were Total Iron, Lead, Copper, Nickel, Manganese, Zinc, Chromium, Cadmium and Cobalt. The analysis shows that the pH value for Station 1 ranges from 4.73 - 6.25, Station 2 pH value ranges from 5.72- 6.27 and Station 3 pH value ranges from 4.55 - 5.55. The mean concentration of heavy metals in Station 1 shows an increasing order of Cd>Cr>Co>Cu>Fe>Pb>Mn>Zn>Ni. The mean concentration of heavy metals for Station 1 shows that Lead (0.771mg/l) and Nickel (0.2522mg/l) are above the WHO and SON standards. The mean concentration of heavy metals in Station 2 shows an increasing order of Cd>Cr>Pb>Cu>Ni≥Co>Fe>Zn>Mn. The mean concentration of heavy metals for Station 2 shows that Lead (0.02325mg/l) and Nickel (0.035mg/l) are above the WHO and SON standard. The mean concentration of heavy metals obtained in the Station 3 shows an increasing order of Cd≥Cr>Ni≥Co>Fe>Mn>Zn>Pb>Cu. The mean concentration of heavy metals for Station 3 shows that Lead (0.044333mg/l) is above the WHO and SON standard. Water quality and pollution index shows that the water quality in all the Station is not suitable for consumption. Pollution index indicates that in station 1 and 2, Nickel and lead are the major pollutants in the water while in station 3, lead is the only major pollutant in the water. In as much as these heavy metals are accumulating, over time they become highly toxic to health.

Content of Selected Macro- and Microelements in Surface Formations of Organic Soils in NE Poland

The research was carried out in the morainic areas and in river valleys in NE Poland, where seven sites located in the macroregion of Masurian Lakeland were selected. Thirteen soil profiles representing the following organic soils were studied: earth-covered murshic soils (OMnm), murshic peat soils (OTmu), hemic murshic soils (OMhe) and sapric murshic soils (OMsa). The aim of the research was to investigate the content of selected macro- and microelements in surface formations of organic soils and to determine the influence of sedimentation processes on their spatial distribution. In terms of quantity, the analyzed macro- and microelements can be arranged as follows: Ca > Al > Fe > K > Mg > Na > P > Mn > Zn > Pb > Cr > Ni > Cu > Co. Organic soils situated in the depressions had various degrees of silting with mineral sediments from the nearby areas. Along with erosive waters, deluvial material rich in minerals was flowing along the morainic slopes. Therefore, mineral-organic formations (AO) located in the ecotone zone between mineral and organic soils had the highest content of total Mg – 4.85 g kg-1, K – 5.94 g kg-1, Al – 24.87 g kg-1, Fe – 17.77 g kg-1, Zn – 0.066 g kg-1, Cr – 0.046 g kg-1, Ni – 0.025 g kg-1, Pb – 0.060 g kg-1. The highest content of total calcium, manganese, iron, copper and cobalt was found in mineral-organic formations (AO) and strongly silted murshes (Mtsz). The contents of calcium and sodium were significantly positively and the contents of other macro- and microelements were significantly negatively correlated with the amount of organic matter, organic carbon and total nitrogen.

Application of pulse current for dissolution of heat-resistant GS32-VI alloy

Objectives. To identify the regularities of electrochemical processing of the heat-resistant GS32-VI alloy in a sulfuric acid electrolyte with a concentration of 100 g/dm3 under the action of a pulsed current in a pulsed mode.Methods. Using the electrochemical technological complex EHK-1012 (developed by IP Tetran) and a non-compensatory method of measuring potential, polarization and depolarization curves with a change in pulse duration and a pause between them were recorded. The current pulses had an amplitude ranging from 0 to 3.5 A (when recording the polarization and depolarization curves), pulse durations ranging from 200 to 1200 ms, and a pause (delay) between pulses ranging from 50 to 500 ms. There were no reverse current pulses.Results. The parameters of the current program that provide the maximum values of the alloy dissolution rate and current output were determined: with a current pulse amplitude of 2 A, a current pulse duration of 500 ms, and a pause duration between pulses of 250 ms, the maximum dissolution rate of the alloy is 0.048 g/h·cm2, while the current output for nickel is 61.6% with an anode area of 10 cm2. The basic technological scheme for processing the heat-resistant GS32-VI alloy, which includes anodic alloy dissolution in a pulsed mode, is proposed.Conclusions. Electrochemical dissolution of GS32-VI alloy under pulsed current action results in an optimal dissolution rate ratio of the alloy components, ensuring the production of a cathode precipitate with a total nickel and cobalt content of 97.5%.

Co-Occurrence of Metal Contaminants in United States Public Water Systems in 2013-2015.

The United States Environmental Protection Agency monitors contaminants in drinking water and consolidates these results in the National Contaminant Occurrence Database. Our objective was to assess the co-occurrence of metal contaminants (total chromium, hexavalent chromium, molybdenum, vanadium, cobalt, and strontium) over the years 2013–2015. We used multilevel Tobit regression models with state and water system-level random intercepts to predict the geometric mean of each contaminant occurring in each public water system, and estimated the pairwise correlations of predicted water system-specific geometric means across contaminants. We found that the geometric means of vanadium and total chromium were positively correlated both in large public water systems (r = 0.45, p < 0.01) and in small public water systems (r = 0.47, p < 0.01). Further research may address the cumulative human health impacts of ingesting more than one contaminant in drinking water.

Inflammatory and coagulatory markers and exposure to different size fractions of particle mass, number and surface area air concentrations in the Swedish hard metal industry, in particular to cobalt

Purpose To study the relationship between inhalation of airborne particles and cobalt in the Swedish hard metal industry and markers of inflammation and coagulation in blood. Methods Personal sampling of inhalable cobalt and dust were performed for subjects in two Swedish hard metal plants. Stationary measurements were used to study concentrations of inhalable, respirable, and total dust and cobalt, PM10 and PM2.5, the particle surface area and the particle number concentrations. The inflammatory markers CC16, TNF, IL-6, IL-8, IL-10, SAA and CRP, and the coagulatory markers FVIII, vWF, fibrinogen, PAI-1 and D-dimer were measured. A complete sampling was performed on the second or third day of a working week following a work-free weekend, and additional sampling was taken on the fourth or fifth day. The mixed model analysis was used, including covariates. Results The average air concentrations of inhalable dust and cobalt were 0.11 mg/m3 and 0.003 mg/m3, respectively. For some mass-based exposure measures of cobalt and total dust, statistically significant increased levels of FVIII, vWF and CC16 were found. Conclusions The observed relationships between particle exposure and coagulatory biomarkers may indicate an increased risk of cardiovascular disease.

Remediation of cobalt from semiconductor wastewater in the frame of fluidized-bed homogeneous granulation process

Green and sustainable strategies aim for the development of manufacturing processes that maximize the use of resources, instigating the semiconductor industry to adopt zero-liquid discharge policies. Complexity and variations in semiconductor wastewater effluents open an opportunity for resource recovery. One such opportunity is the potential recovery of heavy metals such as cobalt and/or copper in chemical-mechanical polishing wastewater, and inorganic anions such as phosphate from etching and acid cleaning. The present work demonstrates the capabilities of homogeneous crystallization in fluidized-bed reactor as treatment technology to process water effluents for industrial reuse while simultaneously recovering precious resources such as copper, cobalt and phosphate. Experimental results revealed that the optimum conditions were achieved at effluent pH of 7.75 – 8.0 and [PO4−3]/[Co2+] of 2.0. Uniform crystal growth was attained due to appropriate fluidization and proper collision of the particles at up flow velocity 40.11 m h−1 with 1.18 kg Co2+ m−2 h−1 loading. Performance was based on the removal/recovery capabilities of cobalt as heavy metal pollutant. The percentage of total cobalt recovered by granulation was 98.8%, whereas 99% cobalt removal was attained at optimal parameters. Coexistence of EDTA and citrate inhibits crystal growth, decreasing the metal granulation capability ~35%. Mixing of copper and cobalt ions in fluidized-bed homogeneous crystallization process was also investigated in which the highest granulation of 95.9% was attained at effluent pH of 6.50 for copper, and 96.8% at effluent pH of 7.50 for cobalt with an equimolar metal concentration of 7.0 mM and phosphate-metal molar ratio of 1.60. The granules recovered were analyzed using XRD and SEM-EDS. The recovered crystals were identified as mineral libethenite (Cu2(PO4)OH) and cobalt phosphate hydrate (Co3(PO4)2.8H2O).

Identification of cobalt in paddy fields in Karawang and Bekasi Districts

Plants need cobalt (Co) for nitrogen fixation and encourage seedling growth. If the amount is excessive, cobalt causes a reduction in crop yield and poisoning. This study aims was to monitor the toxicity levels of cobalt in paddy fields. The study was conducted in the lowland rice fields of Karawang and Bekasi regencies by taking 394 samples of topsoil. The soil samples were collected by survey method. The analysis showed that all samples contained total cobalt, ranging from 0.477 to 31.829 ppm. The data is classified into 3 classes, namely: normal, normal-toxic and toxic under the quality standards of heavy metals in the soil [7]. The classification results showed that 391 samples are categorized as the normal class, 3 samples as the normal-toxic class, and there was no sample categorized as toxic class. The results of this study can be use as a reference for stakeholders to conduct land management to avoid cobalt poisoning.

Atmospheric sources of anthropogenic and geogenic trace metals in Australian lichen and fungi

Trace metals in archived lichen and fungi samples, dating back over 158 years, were measured to ascertain their potential to record temporal shifts in atmospheric source inputs, starting from the onset of industrial activity in Australia to the present. Lichen (Cladonia n = 85; Usnea n = 47) and fungi (Trametes n = 40) samples from the greater Sydney and Melbourne areas were analysed for their total aluminium (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), titanium (Ti) and zinc (Zn) concentrations using inductively coupled mass-spectrometry. We determined enrichment factors (EFs) of each metal, normalised using Al concentration. All metal concentrations were input to the United States Environmental Protection Agency’s Positive Matrix Factorisation (PMF) model to determine the probable contributing sources, with Sydney (n = 81) and Melbourne (n = 91) samples considered separately. Elevated EFs for Cd, Cu, Pb and Zn (14–1211) suggest that anthropogenic inputs have influenced lichen and fungi concentrations, whilst low EFs for Fe and Ti (1–4) imply geogenic source inputs. Elevated EFs for Pb in samples from 1932 to 2002 correspond with the 70-year period of leaded petrol emissions. PMF modelling determined four distinct source factors: Factor 1 – Cr, Co, Fe, Ni, Zn (19.8 % of the total recovered mass) corresponding to metalliferous industries; Factor 2 – Cd, Cu, Zn (5.3 %) typical of smelting, mining and coal combustion emissions; Factor 3 – Pb (6.6 %) dominated by leaded petrol emissions; Factor 4 – Al, Fe and Ti (68.2 %) relating to geogenic sources. The data show that archived Australian lichen and fungi samples provide effective biomarker proxies for atmospheric trace metal contamination. These new data, extending back to the mid-1800s, provide a more nuanced understanding of anthropogenic atmospheric pollution sources since the onset of post European industrialisation on the Australian continent.

Establishment of a research workflow for occurrence state of critical metal in ore concentrate powder: A case study of the cobalt-rich sulfur ore concentrate powder from the Middle-Lower Yangtze River Valley Metallogenic Belt, China

长江中下游成矿带作为我国矿床学研究程度和矿产利用技术水平最高的成矿带之一，大部分矿床中除了主要成矿元素铜、金、铁和硫等，还伴生潜在可利用的关键金属资源镉、钴、硒、碲和铼等。由于目前矿山主要选矿回收铜、铁、硫、铅、锌、金和银等主要矿种，在不改变选矿工艺的条件下，矿山产品矿精粉中关键金属的分布特征和可利用性是当前关键金属资源利用的核心问题之一。本文对成矿带内玢岩型铁矿床、矽卡岩型铁矿床、矽卡岩型铁铜矿床、矽卡岩型铜金矿床、斑岩型铜金矿床和角砾岩筒型铜金矿床等六类矿床的矿山产品（铜金粉、硫精粉、铁精粉和金精粉）进行了系统化学成分分析，发现目前的矿山产品中关键金属元素含量普遍不高，但矽卡岩型铁矿床中的龙桥铁矿床硫精粉中富集钴，具有综合回收利用钴资源的潜力。在此基础上，本次工作利用综合矿物分析技术（TIMA），扫描电镜（SEM）和激光剥蚀-等离子体质谱仪（LA-ICP-MS）三种测试方法，系统开展了富钴硫精粉中钴的赋存状态研究。结果表明，龙桥硫精粉中钴矿物为辉砷钴矿、铁硫砷钴矿和硫铜钴矿，分别占硫精粉中总钴含量的9.93%、0.64%和0.01%。黄铁矿晶格中类质同象形式产出的钴占总量的81.97%，此外还有7.46%的钴赋存在其他矿物中。通过对比研究，初步建立了矿精粉中关键金属元素赋存状态的研究方法流程，为矿精粉中钴的回收利用提供了依据。;The Middle-Lower Yangtze River Valley Metallogenic Belt is one of the metallogenic belts with well-studied economic geology research and comprehensive mineral utilization technology in China. In addition of the main ore-forming elements Cu, Au, Fe and S, most deposits are associated with potentially available critical element resources, such as Cd, Co, Se, Te and Re. At present, the mines processed and recovered Cu, Fe, S, Pb, Zn, Au, Ag and other major products. Without changing the mineral process, the key problems in the utilization of critical element resources are the understanding of the occurrence of critical metals in ore concentrations. We have conducted a systematic chemical composition analysis of the mine products (i.e., copper concentrate powder, sulfur concentrate powder, iron concentrate powder and gold concentrate powder) of six types of deposits in the metallogenic belt, including apatite-magnetite Fe deposit, skarn Fe deposit, skarn Fe-Cu deposit, skarn Cu-Au deposit, porphyry Cu-Au deposit and breccia-hosted Au deposit. It is found that the contents of critical elements (Cd, Co, Se, Te and Re) in those mine products are generally low, except Co enriched in sulfur concentrate powder of Longqiao skarn iron deposit, which has the possibility of recovery and utilization of cobalt resources. In this study, the occurrence of cobalt in Co-rich sulfur concentrate powder was analyzed by Tescan Integrated Mineral Analyzer (TIMA), Scanning Electron Microscope (SEM) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The analyses results show that the cobalt independent minerals in Longqiao sulfur concentrate powder are cobaltite, glaueodot and carrollite, which account for 9.93%, 0.64% and 0.01% of the total cobalt in sulfur concentrate powder, respectively. The amount of cobalt occurs as isomorphic form in pyrite lattice accounts for 81.97% of the total. In addition, 7.46% of cobalt exists in other unknown minerals. Research workflow of critical elements deportments in ore concentrate powder is established initially, which provides a theoretical basis for the recovery and utilization of cobalt in ore concentrate powder.

Chemical Evaluation of Trace Elements in Bottled Water

Sales of bottled water have been increasing around the globe. This study was carried out to assess the trace elements present in bottled water. For the study of bottled water, a total of 100 samples of different volumes (20 L and 1 L) were selected. The physicochemical assessments were performed as per the methods described in the American Public Health Association, 2005. Average values of pH, electrical conductivity, total dissolved solids, and turbidity were found to be 5.96 ± 0.54, 59.97 ± 58.65, 4.42 ± 3.69, and 0.408 ± 0.19, respectively. Likewise, average values of total hardness (as CaCO3), calcium (as CaCO3), magnesium (as CaCO3), chlorine, iron, copper, cobalt, nickel, fluoride, sodium, and potassium were found to be 14.78 ± 8.43, 3.26 ± 1.55, 11.51 ± 7.92, 7.51 ± 3.21, 0.0032 ± 0.0017, 0.0091 ± 0.0116, 0.2520 ± 0.0127, 0.0080 ± 0.0082, 0.047 ± 0.0139, 12.65 ± 10.90, and 1.41 ± 2.00, respectively; meanwhile residual chlorine, zinc, silver, cadmium, and lead were below detection limit. All the physicochemical characteristics of bottled water were found to be within International Bottled Water Association (IBWA) guidelines. From the physicochemical aspects, the bottled water was found to be within the permissible value set by IBWA. Pearson’s correlation revealed significant association between trace elements. Levene’s test for equity of variances indicated that the majority (iron, copper, cobalt, nickel, fluoride, sodium, and potassium) of trace elements and seasons (monsoon and postmonsoon) demonstrated a statistically significant distribution (at 95% confidence interval). At elevated concentrations, some elements can be harmful to human health and can cause morphological abnormalities, mutagenic effects, reduced growth, and increased morbidity and mortality in humans but it all depends upon a person’s metabolic factors, genetic factors, and ability to excrete trace elements through different routes, etc. Water could have percolated down from the surface to the ground water and as such the difference in concentration of trace elements in monsoon and postmonsoon seasons could be noticeable.

Zwitterionic ultrathin covalent organic polymers for high-performance electrocatalytic carbon dioxide reduction

Covalent organic polymers (COPs) or covalent organic frameworks (COFs) are emerging types of electrode materials for electrochemical CO2 reduction reaction (CO2RR) owing to their controllable structures at the molecular level. However, their activities are often limited by stacking structures and low conductivities. Here we report an ultrathin cobalt tetraamino phthalocyanine-squaraine based COPs (COP-SA) for high-performance CO2RR towards CO. The extended π-conjugated skeleton constitutes the layer, and the zwitterionic structure from the squaraine unit helps the dispersion of layers, leading to an ultrathin thickness of ∼1.7 nm. The ultrathin nanostructure avoids the common agglomeration issues for molecular catalysts and thick nanomaterials, which is beneficial to afford highly exposed active sites and efficient electron transfer for electrochemical reactions. Theoretical calculation suggests that the squaraine unit will enhance the COOH adsorption and favor the CO desorption. These collectively conduce to a high current density of 9.74 mA cm−2 with 96.5 % CO faradaic efficiency, a large turnover frequency of 46 s-1 (by total cobalt site) at -0.65 V vs RHE and excellent cycling stability. This work underscores the structural and electronic effects for the rational design of ultrathin COPs materials for electrochemical CO2RR.

Total Mercury, Methylmercury, Selenium and Cobalt Levels in Maternal and Cord Serum Pairs: Relevance for Antioxidant Response and Oxidative Stress

Total Mercury, Methylmercury, Selenium and Cobalt Levels in Maternal and Cord Serum Pairs: Relevance for Antioxidant Response and Oxidative Stress

Identification of biomarkers measured upon arrival associated with morbidity, mortality, and average daily gain in grain-fed veal calves

There is a strong need for management strategies that help reduce the incidence of disease and subsequent antimicrobial use in the veal industry. Biomarkers could serve as useful tools that allow producers to take preventative measures before clinical problems occur. The objective of this prospective cohort study was to identify biomarkers measured upon arrival associated with morbidity, mortality, and average daily gain (ADG) in grain-fed veal calves. Upon arrival at a grain-fed veal facility in Ontario, Canada, calves were weighed and health-scored using a standardized health-scoring system. Several metabolites were measured including creatine kinase (CK), cholesterol, haptoglobin, manganese, serum total protein, iron, cobalt, zinc, selenium, molybdenum, and IgG. Farm personnel treated calves according to their farm protocol and weighed them at 78 d after arrival. Performance, treatment, and mortality records from the facility were used for analysis. Multivariable Cox proportional hazard models were created to evaluate metabolic biomarkers associated with morbidity and mortality. A mixed linear regression model was created to determine biomarkers associated with ADG. A total of 992 male dairy calves were evaluated at arrival from January to December 2017. Of the calves evaluated, 74 calves (7.5%) died and 877 (88.4%) were treated for illness over the 11-wk period under observation. Higher levels of haptoglobin and molybdenum were associated with a greater hazard of morbidity, whereas higher weight upon arrival and higher levels of both CK and IgG were associated with a reduced hazard of morbidity. For mortality, higher weight upon arrival and higher levels of cholesterol and IgG were associated with a lower hazard of mortality occurring over the 78-d period of observation. Higher weight, cholesterol, copper, CK, iron, and IgG were associated with increased ADG, whereas increased zinc and haptoglobin were negatively associated with ADG. These results demonstrate that certain biomarkers could be used to identify high-risk calves when measured upon arrival at a veal facility. Future research should focus on determining the utility of these biomarkers to selectively target intervention strategies to improve ADG and reduce morbidity and mortality.

Efficient activation of peroxymonosulfate on cobalt hydroxychloride nanoplates through hydrogen bond for degradation of tetrabromobisphenol A

Heterogeneous activation of peroxymonosulfate (PMS) using cobalt-based nanomaterials is a promising strategy to degrade organic pollutants, in which the formation of Co(II)OH complex is a critical step. Here, cobalt hydroxychloride (Co2(OH)3Cl) nanoplates were synthesized by a one-pot precipitation method and exhibited high activity for the degradation of tetrabromobisphenol A (TBBPA) in the presence of PMS. The use of Co2(OH)3Cl and PMS caused a complete TBBPA degradation (40 mg L−1) at pH 9 in 2 min. The pseudo-first-order rate constant of TBBPA is 2.5 min−1, being 9, 14, and 6 folds larger than those for α-Co(OH)2, β-Co(OH)2, and Co3O4 as catalysts, respectively. The dissolved Co2+ (0.15 mg L−1) corresponds to 0.24% of the total cobalt in Co2(OH)3Cl and has negligible influence on the TBPPA degradation. Co2(OH)3Cl shows long-term stability (longer than 9 months) with the high activity after the oxidation treatment. The high activity of Co2(OH)3Cl attributes to the Cl− enhanced reactivity of surface Co(II)OH. The coordinated Cl− not only enhances the ability of surface Co(II)OH for anchoring both HSO5− and SO52− through the intermolecular hydrogen bond, but also improves electron transfer between Co(II) and PMS, leading to efficient generation of singlet oxygen for the TBPPA degradation.

The Effect of Different Doses of Sewage Sludge and Liming on Total Cobalt Content and its Speciation in Soil

The aim of this paper is to evaluate the effect of liming and various doses of municipal sewage sludge (5, 10, and 15% of the weight of the soil) on cobalt total content and its speciation. The incubation experiment lasted 420 days and was conducted in controlled laboratory conditions. Soil was sampled after 30, 60, 90, and 120 days and then, with a break of 180 days, after 360 and 420 days. In all samples, cobalt total content was determined by means of ICP-AES (emission spectrophotometer), and fractions of this metal were measured with the seven-step Zeien and Brümmer method, with seven of them separated: F1–easily soluble, F2–exchangeable, F3–bound to MnOx, F4–bound to organic matter, F5–bound to amorphous FeOx, F6–bound to crystalline FeOx, and F7–residual. Compared to the control, the average content of total cobalt in the soil increased more than two times in experimental units with higher doses of sewage sludge (10% and 15% of the weight of the soil). The metal was mainly bound to the residual fraction, where it constituted 40% of its total content, while in the organic fraction, its share was 20%. In the soil incubated with sludge, cobalt in mobile fractions constituted a small percentage of its total content. Liming limited the release of this metal.

How New Business Models Can Address Human Rights Risks in the Cobalt Supply Chain

Cobalt is an essential component of the lithium-ion batteries that power our phones, laptops, and other portable consumer electronics.Its consumption is expected to multiply eightfold by 2026 and 14 times its current levels in the next decade. With no alternatives to the Democratic Republic of Congo's (DRC) production capacity, companies that manufacture batteries are dependent on Congolese cobalt. The so-called artisanal small-scale mining (ASM), a term that refers to mining without heavy machinery, accounts for 20% to 30% of the country’s total cobalt production. What is evident is that working in the Congolese mining sector is dangerous, with particularly high risks related to legal yet largely unregulated ASM. Human rights issues have been documented in many artisanal mines in the country, including child labor, serious health and safety risks, and fatal accidents.Considering the projected rise in cobalt demand, finding collective and permanent solutions to human rights issues in ASM is a timely and urgent quest. Companies sourcing from the DRC are under increasing pressure to address these human rights challenges. This paper analyzes the business solutions that companies are currently exploring to formalize ASM. Addressing human rights issues in ASM requires companies to reorganize core business processes in a way that systematically integrates respect for human rights in all supply chain links upstream. In our initial case study we are focusing on a Swiss commodity trading company that is driving an innovative project to regulate ASM at a mining site at Kolwezi, in Katanga, DRC. We see this case study as a preliminary research phase into a comparative project of business models of companies sourcing precious metals from the DRC. The goal is to distill the business factors that have a systemic positive impact on the workers and communities involved in ASM. This paper is structured in four parts. In the first part of the paper, we provide data to underpin the relevance of the DRC for the global cobalt supply chain. We also highlight the role of ASM in this supply chain and the impact that cobalt price fluctuations have on ASM. In the second part, we outline the pilot project that the commodity firm Trafigura has set up at the Mutoshi mine in the DRC to control for the human rights risks related to ASM. The case is considered as a model example for formalizing ASM. We describe our research plans to assess this project in the field in order to identify the business factors that need to be in place for such a project to be scalable and replicable by other companies, including companies in other sectors. The third part outlines other companies’ projects that attempt to control for human rights risks related to ASM. We hope to eventually to study them in greater detail in a comparative setting. Finally, in part four, we look at the specific role that commodity-trading companies play in the cobalt supply chain and the current drivers for the described pilot projects. We will also consider how multi-stakeholder initiatives in this industry can facilitate the development of standards for responsible ASM.

Electrospun iron/cobalt alloy nanoparticles on carbon nanofibers towards exhaustive electrocatalytic degradation of tetracycline in wastewater

Rough surfaced carbon nanofibers bearing evenly distributed iron/cobalt alloy nanoparticles (Fe/Co-CNFs) are developed through the electrospinning of polyvinylpyrrolidone (PVP) mingled with 5.0 wt% of total ferric nitrate and cobalt nitrate concentration, followed by direct calcination of PVP composite nanofibers at 800 °C for 30 min in a reduction atmosphere. With a large specific surface area and active sites, the Fe/Co-CNFs could serve as an excellent anode material for the complete electrocatalytic degradation of tetracycline into carbon dioxide and water at a bias voltage of 1.0 V (vs. SCE) in a solution with pH value of 5.0 and 0.1 mol L−1 Na2SO4 as the supporting electrolyte. The observed tetracycline degradation percentage of 97.55% even after ten cycles of electrocatalytic process for Fe/Co-CNFs modified electrode indicates an excellent stability, recyclability, and reusability. This work provides a novel material for environmental remediation of antibiotic contaminated water.

Determination of cobalamin in chlorella food by cation exchange column and graphite furnace atomic absorption spectrometry

A method for the rapid determination of cobalamin (Vitamin B12) in chlorella food was proposed. This method utilized a strong cation exchange column to remove free cobalt (II), and the cobalamins were quantitatively determined by measuring total cobalt in the column effluent with graphite furnace atomic absorption spectrometry (GFAAS). Under optimized conditions, the method detection limit was 24 μg/100 g. The method was validated by spiking cobalamin standards in different chlorella food, recoveries from spike preparations ranged from 98.3 to 99.5%, with coefficients of variation of 1.2-4.9%. The results show the suitability of the proposed method for determining vitamin B12 in chlorella food.