ICP-MS Technique Research Articles

Studying the process of metals and non-metals transfer in a low-temperature gas flow over sulfide tailings materials

ABSTRACT A large number of publications have been devoted to the study of aerosol atmospheric transport, but the low-temperature transfer of metals and metalloids as a part of gas flow remains poorly understood. The present work is devoted to the study of gas stream composition using an approach based on the collection of nascent condensate upon cooling of the air flow formed over the surface of contaminated sites. A special laboratory unit was designed to collect the condensate followed by the study of its composition using atomic emission and mass spectrometry. The main novelty of this work consists of the application of the single-particle ICP‒MS technique to obtain qualitative information concerning the state of the elements in the condensates. Gold and silver are most likely present in the samples as nanoparticles; arsenic, selenium, tin and lead are present both as nanoparticles and as soluble forms; and barium and mercury are present only in soluble forms. The condensed phase contains As, Hg, Au, Ag, Pb and Sn at the ppb level, while the main elements of the tailings material (Fe, Ba, Cu, Zn and others) are present at the ppm level, which exceeds the background concentration.

Evaluation of potential human health risks associated with Li and their relationship with Na, K, Mg, and Ca in Romania's nationwide drinking water.

Increasing lithium (Li) demand worldwide due to its properties and role in renewable energy will raise water reservoir pollution and side effects on human health. Divergent results regarding Li concentration in water and affective disorders are found in the literature, which is why regional reports are expected. The present study evaluated the occurrence and human health risks resulting from oral exposure, respectively, and the relationship between alkali metals (Li, Na, and K) and minerals (Mg, Ca) in balanced purified water (bottled) and spring water. The ICP-MS technique was used to measure a national database with 53 bottled and 42 spring water samples randomly selected. One-way ANOVA, Pearson correlation, and HCA analysis were applied to assess the possible relationship between metals in water. The possible side effects of Li poisoning of water resources on human health have been evaluated using the Estimated Daily Intake Index (EDI) and Total Hazard Quotient (THQ). The toxic metals (As, Hg, and Pb) were measured, and the results indicate values above the detection limit of 22.3% of samples in the case of lead but not exceeding the safety limits. Depending on the water sources, such as bottled and spring water, the Li concentration varied between 0.06-1,557 and 0.09-984% μg/L. We found a strong positive correlation between Li and Na and Mg, varying between bottled and spring waters (p% <%0.001). Li exceeded the limit set by the Health-Based Screening Level (HBSL) in 41.37 and 19% of bottled and spring water samples. The oral reference doses (p-RfDs) for the noncancer assessment of daily oral exposure effects for a human lifetime exceeded threshold values. The THQ index shows potential adverse health effects, requiring further investigations and remedial actions in 27.58% of approved bottled waters and 2.38% of spring waters. We can conclude that water is safe based on the Li concentration found in drinking water and supported by a gap in strict regulations regarding human Li ingestion. The present study can serve decision-makers and represent a starting database with metals of interest for further clinical studies. Decision-makers can also use it to find solutions for sustainable management of clean and safe drinking water.

BIOACCUMULATION OF CU AND CO IN LEAFY AND FRUIT VEGETABLES FROM THE SUBURBS OF MITROVICA, KOSOVO

Contamination of vegetables with heavy metals is one of the basic environmental problems, especially in developing cities, primarily due to the uncontrolled level of pollution caused by industrial growth and the increase in the number of vehicles using petroleum fuels. This paper aims to determine the bioconcentration of heavy metals Cu and Co in leafy and fruit vegetables grown near Kosovska Mitrovica (Republic of Kosovo). Three places near Kosovska Mitrovica (Zvečan, Frashër, and Polski) are grown: parsley, spinach, lettuce, peppers, eggplant, and cucumber. All analyzed crops are from the 2023 harvest. In the same period, an analysis was made of the soil on which the crops were grown. The bioconversion factor (BF)of the selected leafy and fruit vegetables was also determined. The ICP-MS technique was used to determine the concentration of Cu and Co in soil and leafy and fruit vegetables. From the obtained analyzes it was determined that the soil in Frashër contains the highest amount of Cu and Co - 58.4 mg/kg and 11.6 mg/kg respectively. The amount of Cu in the examined dry leafy and fruit vegetables is in the range from 5.38 mg/kg to 22.4 mg/kg, and of Co from 0.27 mg/kg to 2.99 mg/kg. The bioconcentration factor of the studied leafy and fruit vegetables of Cu and Co is in the range of 0.04 to 0.26 and 0.15 to 0.65 respectively. The accumulation of Co in the analyzed vegetables is higher than the accumulation of Cu, due to the higher BF values for Co. The statistical processing of the results (t-test) showed that there is a difference in the concentration of Cu and Co between leafy and fruit vegetables, but there is no statistically significant difference because the obtained p-values are greater than the marginal p-values.

Migmatite-Gneiss-Granite Basement of Southwestern Nigeria: Mineralogical and Geochemical Evidence for a Possible Common Ancient Protolith

Nigeria occupies southern section of the Pan-African orogenic belt and migmatite-gneiss-granite terrain forms a major component of its basement complex. Field geology, optical mineralogy and geochemical study of this rock unit in Idanre area, SW Nigeria were undertaken with a view to characterize them, elucidate their tectonic significance, and determine their origin. Major, trace and Rare Earth Elements (REE) composition were determined by XRF and ICP-MS techniques respectively in Bureau Veritas, Vancouver, Canada.

Preparation, Characterization and Optical Analysis of Chromium Doped 45S Bioactive Glass-Ceramic

The 45S Bioactive glass-ceramic (BG) and Chromium (Cr)-doped BG materials were successfully produced in this study. XRD, FTIR, and ICP-MS techniques were used to characterize the prepared materials. The XRD testing showed that all samples contained pure BG. Increased Cr ion inclusion shifted the BG diffraction peaks to a lower value of 2 Theta and increased crystallinity. FTIR was used to detect Si-O, P-O, and Ca-O functional groups. Cr ions steadily decreased the Ca-vibration mode area. The ultraviolet-visible spectrophotometry was used to measure the optical characteristics of pure and Cr BG-doped materials. The Cr-doped BG was green in colour, whereas the lab-synthesized BG was white. Two additional bands formed at 433 and 615 nm when Cr ions were doped into the BG structure. These bands may be caused by 4A2 → 4T1 and 4A2 → 4T2 electronic d-d transitions. The findings show that biomedical applications may exist for fluorescent probes manufactured from Cr-BG materials.

Toxic elements identified in breast milk of mothers residing in water contaminated region of Sindh and their impact on infants’ growth patterns: A case-control study

Breast milk is a vital source of nutrition for breastfed infants, providing essential nutrients and elements but, in some cases, toxic ones. This is the first case-control study that investigated the elemental profile of breast milk samples collected from mothers residing in Matiari (Sindh), a region with insufficient industrial waste management, and its potential impact on infants' anthropometrics. Precisely, 62 milk samples, including 42 cases and 20 controls, were analyzed using the ICP-MS technique. Overall, six elements showed significance between the two groups, arsenic (As) was present at 0.68 μg/L in cases and absent in controls, while lead (Pb) exhibited elevated concentrations in the case group at 4.56 μg/L compared to 0.25 μg/L in controls, well-known for their toxicity. Barium (Ba) and manganese (Mn) levels were also higher in cases, associated with reported health effects on child well-being. Essential elements molybdenum (Mo) and selenium (Se) were higher in the controls. Furthermore, the association of these metals with the child growth standards as per WHO guidelines was calculated. Linear regression analysis revealed As negatively associated with WAZ and WHZ scores, while Mo was positively associated with WAZ, WHZ, and HAZ scores. These findings highlight serious health concerns in the region, where toxic elements pervade drinking water and food sources. Immediate actions are imperative to maintain the wellness of future generations.

Geochemical characteristics of Neoproterozoic metavolcanic rocks of Ariab Auriferous Volcanogenic Massive Sulfide deposit, Red Sea hills, North-East Sudan

The Ariab volcanogenic massive sulfide (VMS, ∼118.3 Mt with >2 Moz Au recovered) district is part of the Ariab-Arbaat belt located in the Haya terrane, Red Sea Hills, Northeast Sudan. The gold-bearing gossan and VMS deposits are mainly hosted by Neoproterozoic bimodal volcanic succession. The petrogenesis, age dating, metallogenic evolution, and tectonic environment as well as the relationship between the metals occurrences and hosting materials remain poorly constrained and controversial. The study aims to investigate the geochemical characteristics of metavolcanic rocks of Ariab Auriferous Volcanogenic Massive Sulfide. XRF and ICP-MS techniques were employed to analyze major, trace, and rare earth elements content. The metavolcanics composition of Ariab VMS hosting rocks ranging from basalt to rhyolitic lava with variable pyroclastics. The chemical affinity varies from sub-alkaline tholeiitic to calc-alkaline nature, raising an argument against the possibility of fractional crystallization. The Ariab VMS metavolcanics were likely formed in the intra-oceanic arc tectonic environment. Ariab mafic lava is characterized notably by high Cr and Ni concentrations. The negative and positive anomalies in trace element profiles are typically ocean island basalt patterns, implying minimal crustal contamination. The geochemical results of dacitic and rhyolitic rocks reveal an assimilation-fractional-crystallization process, including the possibility that plagioclase-rich restite was formed in the parent magma source with a significant contribution from the old crust. The mobility of elements such as Zn, Cu, Pb, Ag, Au, As, and Co complicates the determination of their primary abundances. The partitioning behavior of REEs, the geochemical signatures of chalcophile elements, and their associations with VMS deposits, underscores the complex interaction between igneous processes and subsequent hydrothermal alteration.

Exposure to heavy metals, antioxidant status, and the interaction of single nucleotide polymorphisms in the genes CAT rs7943316, GSTP1 rs1695, as well as GSTM1 and GSTT1 genes, among workers in occupational settings

Individuals working in diverse fields are consistently exposed to work-related pollutants that can impact their overall health. The current study investigated the presence of pollutants in seven different occupational groups and their impact on human health. Biochemical and genetic approaches were employed. Heavy metals were determined by ICP-MS technique. Oxidative stress biochemical markers and molecular analysis of the glutathione transferases gene SNPs (GSTT1, GSTM1, GSTP1), catalase (CAT, rs7943316), and superoxide dismutase (SOD, rs17880487) was carried out. The results revealed a significantly higher quantity of Cd among five occupational groups. Catalase, malonaldehyde, and glutathione was significantly dysregulated. Molecular analysis of the gene SNPs suggests a probable relationship between the antioxidants and the phenotypic expression of the CAT, GSTP1, GSTT1, and GSTM1 SNPs. It is concluded that chronic exposure to occupational contaminants like Cd affects human health through oxidative stress in association with some of their gene SNPs.

STATISTICAL ANALYSIS OF Li CONCENTRATION AND THE 6Li/7Li ISOTOPIC RATIO FROM SPECIFIC PROVENANCE ENVIRONMENTS

Starting from the necessity of a geospatial footprint existence of mineral waters in Romania, this study followed lithium concentration distribution and the 6Li/7Li isotopic ratio using the ICP-MS technique. Stable isotopes are potent tracers of chemical and biological transformations in natural environments. Lithium is commonly found as a dissolved species in groundwater and surface water, making this valuable metal a conservative tracer in hydrogeological studies. This study followed the geographical distribution of lithium concentrations and the 6Li/7Li isotopic ratio, considering the comparative characterization of Romanian waters (from different geographical regions) and foreign waters sold on the Romanian market and independent food stores. The determination of the median values was based on the bootstrap method, which allowed the identification of high values of the standard errors in the case of Li concentration in the approved waters and the organic material. In the case of the isotopic ratio, the highest value is found in foreign waters. The waters of Southern Muntenia presented significantly different values compared to all other regions, having the lowest concentration of Li (0.44 µg/L) but having the highest isotopic ratio (0.10). The waters of the S-W Oltenia and Central Transylvania regions have the highest concentrations of Li, respectively 10.45 µg/L and 10.03 µg/L, much lower than the values of the other regions. Also, the organic material shows a degree of Li concentration dispersion but the slightest variation in the isotopic ratio. The involvement in human health of Li exposure is needed for further investigation even if no regulation on the safe limits of Li in drinking water for humans is addressed

A multi-source proxies approach to identifying local processes in lower Permian black shale impacting on the sedimentary environment of eastern Palaeo-Tethys Ocean

Foreland basin tectonics along the eastern Palaeo-Tethys Ocean produced a complex and dynamic pattern of sediment delivery to adjacent basins. Environmental processes at the local scale significantly disrupt regional ones, making the analysis of sedimentary evolution difficult. This study investigated the Lower Permian Liangshan Formation black shale formed in such geological setting, rich in cherts with exceptionally high silica and fluctuating major and trace element concentrations, detected using XRD, XRF, and ICP-MS techniques. Different types of silica, including detrital quartz, recrystallised radiolaria, microcrystalline quartz, and quartz veins, were identified using SEM and SEM-CL imaging. Geochemical characterisation and enrichment pattern analyses indicated that the structural setting was characterised by proximity to the oceanic island arc, continental island arc, and passive margin, and the major zone of sediment accumulation was a semi-restricted back-arc basin under the subduction zone. The processes controlling sediment accumulation included hydrothermal activity, upwelling, biogenic silica, and terrestrial inputs. Although upwelling interfered with the mobility and migration of hydrothermal elements, it introduced abundant nutrients, and together with hydrothermal fluids, it contributed to the subsequent boom in siliceous organisms. Terrigenous inputs induced by land uplift significantly diluted the components from other sources. This multi-source proxies approach not only enables researchers to disentangle local from regional processes but also sheds light on how these diverse environmental forces interact within intricate earth systems, which enhance our comprehension of geologic history and inform ongoing studies focused on climate change mitigation strategies.

A new method for screening elemental impurities in medico-pharmaceutical disinfectants

Healthcare associated infections consist a major concern in South-East European countries. As hospital activities try to eliminate the possible risks of infections, the quality of the disinfectants used in surgical sites, microbiological laboratories and other aseptic places must be ensured by using a proper product. In this context, the PEROKLIN product produced by Klintensiv Ldt., Romania, was tested using ICP-MS technique at the IFIN-HH Chemical and Physical Test Laboratory in terms of determining the elemental concentrations of several elements of interest. A dedicated chemical protocol was developed for that purpose and the method was validated according to international guidelines.

Metal leakage from orthodontic appliances chemically alters enamel surface during experimental in vitro simulated treatment

Human enamel is composed mainly of apatite. This mineral of sorption properties is susceptible to chemical changes, which in turn affect its resistance to dissolution. This study aimed to investigate whether metal leakage from orthodontic appliances chemically alters the enamel surface during an in vitro simulated orthodontic treatment. Totally 107 human enamel samples were subjected to the simulation involving metal appliances and cyclic pH fluctuations over a period of 12 months in four complimentary experiments. The average concentrations and distribution of Fe, Cr, Ni, Ti and Cu within the enamel before and after the experiments were examined using ICP‒MS and LA‒ICP‒MS techniques. The samples exposed to the interaction with metal appliances exhibited a significant increase in average Fe, Cr and Ni (Kruskal–Wallis, p < 0.002) content in comparison to the control group. The outer layer, narrow fissures and points of contact with the metal components showed increased concentrations of Fe, Ti, Ni and Cr after simulated treatment, conversely to the enamel sealed with an adhesive system. It has been concluded that metal leakage from orthodontic appliances chemically alters enamel surface and microlesions during experimental in vitro simulated treatment.

Spatial Variability of Rare Earth Elements in Groundwater in the Vicinity of a Coal-Fired Power Plant and Associated Health Risk.

This study investigated the occurrence and distribution of rare earth elements (REEs), including 14 lanthanoids, scandium (Sc), and yttrium (Y), in groundwater around a large coal-fired thermal power plant (TPP). The ICP-MS technique was used to analyze 16 REEs in groundwater samples collected from monitoring wells. REE concentrations ranged from 59.9 to 758 ng/L, with an average of 290 ng/L. The most abundant was Sc, followed by La, accounting for 54.2% and 21.4% of the total REE concentration, respectively. Geospatial analysis revealed the REE enrichment at several hotspots near the TPP. The highest REE concentrations were observed near the TPP and ash landfill, decreasing with the distance from the plant and the landfill. REE fractionation ratios and anomalies suggested the Light REE dominance, comprising over 78% of the total REEs. Correlation and principal component analyses indicated similar behavior and sources for most REEs. Health risk assessment found hazard indices (HI) of 1.36 × 10-3 and 1.98 × 10-3 for adults and children, respectively, which are far below the permissible limit (HI = 1). Likewise, incremental lifetime cancer risks (ILCR) were all below 1 × 10-6. Nevertheless, ongoing ash disposal and potential accumulation in the environment could elevate the REE exposure over time.

Improved Activity and Durability of Carbon-Coated Pd and PdNi Anode Catalysts in AEMFC

Anion exchange membrane fuel cells (AEMFC) have received growing attention due to the strategic potential of using low content (or absence) of PGM catalysts in the electrodes.[1] Completely PGM-free cathode catalysts are well established in those conditions,[2] while the anode ones remain critical in terms of the beginning-of-life activity and long-term performance.[3] The widely Pt- and Pd-based catalysts degrade mainly by nanoparticles detachment and agglomeration in alkaline conditions.[4] These degradations may be slowed down by wrapping the nanoparticles in some carbon layers (called carbon-coated), that prevent also metal oxidation and leaching into the electrolyte in the RDE setup.[5] However, the performance in AEMFC of carbon-coated nanoparticle catalysts is still unclear.Here, two groups (previously characterized in RDE, XRD, IL-TEM, XPS and ICP-MS techniques[5]) of carbon-coated catalysts were investigated in 5 cm2 AEMFC: monometallic Pd (Pd@C/C) and bimetallic PdNi (PdNi@C/C) nanoparticles supported on carbon, and compared them to unprotected ones (Pd/C and PdNi/C). The four different anode catalysts were compared for a fixed Pd anode loading of 0.27 mgPd cm-2, and were combined with a ZIF-8 derived Fe-N-C cathode catalyst (previously developed Fe0.5-NH3). The Pd@C/C and PdNi@C/C reached superior initial performances (700 and 1300 mA cm-2) than the Pd/C and PdNi/C references (300 and 390 mA cm-2) at 0.6 V and Tcell = 60 °C. This translates into an initial activity trend of PdNi@C/C > PdNi/C > Pd@C/C > Pd/C. After 12 h durability test at a cell voltage of 0.3 V, the AEMFC with the PdNi@C/C based anode exhibits a dramatically higher retention of performance (95%) than the cells with Pd/C (55%) and PdNi/C (70%) anodes. These results evidence the robustness of bimetallic carbon-coated nanoparticle catalysts for AEMFC anodes. Figure 1

Statistical analysis of the content of metals in blood serum and in the alternative material in head and neck carcinoma

The study attempted to demonstrate the differences in the content of essential and toxic metals in the blood serum and in the alternative material (hair and nails) in patients with head and neck cancer compared to healthy people. Selected metals were determined in the test material with the ICP MS technique. The obtained results were subjected to statistical analysis. The Kolmogorov-Smirnov test was used to verify the hypothesis that each tested chemical compound taken from other tissue affects the possibility of developing head and neck cancer or is an indicator of the disease. All variables (n = 30) were evaluated to verify significant differences (p < 0.05) in each mean between healthy (n = 55) and cancer groups (n = 68). The data matrix was pre-standardized prior to the analyzes due to large differences in the mean of the compounds tested. The unsupervised learning methods were used and supervised learning methods. On the basis of the statistical analysis, the usefulness of the analysis of alternative material was demonstrated in the potential identification of changes caused in people with cancerous changes at a time when they are not yet visible in the blood serum and can be used as a supplementary test in the diagnosis of head and neck cancer. This is particularly important at early cancer as usually laryngeal cancer is diagnosed in advanced stage.

Chemoecological Monitoring of Water Quality in the Ham Luong River (Mekong Delta, Vietnam)

Investigation of concentrations of organic and inorganic pollutants (hydrocarbons, including oil hydrocarbons, and trace elements – heavy metals and metalloids) in the Ham Luong River in the Mekong Delta was carried out and water quality was assessed by comparing the obtained levels of values with the regulatory limits of concentration. The determination of the total content of hydrocarbons and oil hydrocarbons was made by gas chromatography method; the trace elements were measured by ICP-MS technique after chemical treatment of samples. The content of oil hydrocarbons in the Ham Luong River water ranged from 0.042 to 0.076 mg/l. These values were quite high, exceeding the sanitary standard (0.05 mg/l) for fishery reservoirs, or approaching it, but they were lower compared to Vietnam national standard for domestic supply water (0.1 mg/l). The content of hydrocarbons in suspended matter was in the range of 0.011–0.37 mg/l. The concentrations of 15 trace elements were studied, nine of them (Ni, Fe, V, As, Se, Be, Cd, Sb, Tl) did not exceed any of the established regulatory limits of concentration for surface water. However, concentrations of six trace elements (Pb, Zn, Cu, Co, Ag, Mo) were found to exceed the standard regulatory limits. Among the studied 15 trace elements, critical and potentially critical elements were identified, which are subject to primary monitoring control. Chemoecological studies of water quality are important for monitoring of the ecological and sanitary water state for ensure the quality of consumed natural resources and to preserve the biological diversity of the Mekong Delta ecosystems.

Geochemical distribution and environmental assessment of potentially toxic elements in farmland soils, sediments, and tailings from phosphate industrial area (NE Algeria)

This study investigates the extent and spatial distribution of Potentially Toxic Elements (PTEs) in the Djebel Onk phosphate mine area in south-eastern Algeria, as well as the associated risks to human health. Various scales are considered and sampled, including tailing waste (n = 8), surrounding farmland soil (n = 21), and sediments (n = 5). The samples were mineralogically and chemically analyzed using XRD, FTIR, XRF, and ICP-MS techniques. Principal Component Analysis (PCA) was applied after transforming the raw data into centered-log ratios (clr) to identify the dominant factors controlling the distribution of PTEs. Furthermore, pollution assessment was conducted using several indices, including geo-accumulation, pollution load, contamination security indices, and enrichment and contamination factors. The results reveal that the analyzed samples are mostly P-enriched in the mine tailings, farmland soil, and sediments, with P2O5 concentrations ranging from 13.37 wt% to 26.17 wt%, 0.91–21.70 wt%, and 17.04–29.41 wt%, respectively. The spatial distribution of PTEs exhibits clearly a decrease in the contents of CaO, P2O5, Cr, Sr, Cd, and U with increasing distance from the mine discharge site, while other oxides, such as MgO, Al2O3, SiO2, K2O, and Fe2O3, and associated elements (Cu, Co, Pb, and Zn), show an increase. PCA confirms the influence of minerals such as, apatite, dolomite, and silicates on the distribution PTEs. It denoted that the highest contamination level of all PTEs in soils and sediments was observed in the southern part of the plant and mine tailings compared to the northern part. In terms of human health risks, the assessment reveals that the hazard index (HI) values for both non-carcinogenic and carcinogenic risks associated with PTEs in the study area are below 1, suggesting no significant risk. However, regardless of the sample type, the lifetime cancer risk (LCR) values vary from 1.69E-05–2.11E-03 and from 1.03E-04–2.27E-04 for Cr, Ni, As (children) and Cd (adults), respectively, exceeding the safe levels recommended by the United States Environmental Protection Agency. The study highlights that oral ingestion poses the greatest risk, followed by dermal contact and particle inhalation. Importantly, all these indices decrease with increasing distance from the sampling site to the waste discharge point and the factory, which indicates that the phosphate mining activity had caused some extent risks. These findings provide valuable insights for mitigating the adverse health impacts and guiding environmental management efforts.

Evaluation of Total and Lipid-Bound Sialic Acids, Trace and Macro Elements, and Some Biochemical Parameters in Dogs with Babesiosis

The present study was designed to investigate the changes at the levels of total sialic acid (TSA), lipid-bound sialic acid (LSA), trace and macroelements, and some biochemical parameters in dogs naturally infected with babesiosis. While babesiosis group consisted of seven dogs which were diagnosed with babesiosis clinically and parasitologically (ELISA), control group consisted of seven healthy dogs. Serum TSA and LSA levels in blood samples were measured spectrophotometrically by Sydow and Katapodis methods, respectively. Some biochemical parameters and macroelement measurements were performed using a modular autoanalyzer device. Trace mineral measurements were performed by ICP-MS technique. Compared to the healthy group, dogs with babesiosis had considerably higher TSA and LSA levels. Serum AST, ALP, LDH and CK enzyme activities and CRP, glucose, globulin, total bilirubin, urea, uric acid, creatinine and BUN levels of the babesiosis group significantly increased, while total protein level significantly decreased. The changes in ALT enzyme activity and triglyceride, cholesterol, HDL, LDL, HDL-CDL and ferritin levels were not statistically significant. Zinc, copper, magnesium, sodium, and potassium levels of the babesiosis group decreased significantly, while iron and chlorine levels increased significantly (p

Assessing Heavy Metal Contamination Using Biosensors and a Multi-Branch Integrated Catchment Model in the Awash River Basin, Ethiopia

Metal pollution in rivers from untreated industrial and domestic wastewater is a major issue in economically developing countries worldwide. The Awash River Basin in Ethiopia is one of those rivers that faces rising heavy metal concentrations due to poor wastewater management and loose law enforcement controlling effluent discharge into rivers. In this study, surface water and wastewater samples were collected within the Awash River Basin, with metals analysis using ICP-MS techniques. Acute toxicity of water was determined using new molecular biosensor technology based on engineered luminescent bacteria. A multi-branch Integrated Catchment Model (INCA) for metals, including Arsenic, Cadmium, Chromium, Copper, Lead, Manganese, and Zinc was applied to the Awash River Basin to simulate the impact of tannery discharge on the river water pollution levels and to evaluate a set of treatment scenarios for pollution control. Results show that all samples from tannery wastewater have high levels of metals, such as Chromium and Manganese with high levels of toxicities. River water samples from upper Awash near Addis Ababa showed elevated concentrations of heavy metals due to the untreated wastewater from the dense population and a large number of industries in that area. The modeling scenarios indicate that improved wastewater management will reduce the metal concentration significantly. With a 50% reduction in effluent concentrations, the mean concentrations of heavy metals (such as Chromium) over two years would be able to reach 20 to 50% reduction in river water samples.

Innovative Post-Processing for Complex Geometries and Inner Parts of 3D-Printed AlSi10Mg Devices.

A new technology consisting of new and sustainable chemical polishing treatment for aluminum components with complex shapes, such as heat exchangers, manifolds, busbars, aerospace devices, etc., manufactured by Additive Manufacturing (AM) technologies is described in this paper. This technology will contribute to the development of a more efficient manufacturing process driven by AM, reinforcing the main idea of AM, which is based on reducing the amount of material and achieving cost savings through smart and improved designs. The present study shows a significant reduction in the surface roughness of consolidated AlSi10Mg metal parts manufactured by the SLM technique after carrying out the new chemical polishing post-process investigated in this work. Roughness values have been measured by mechanical and optical profilometry. The results obtained demonstrate the effectiveness of the chemical polishing, decreasing the roughness by up to 40%, being a reproducible and repeatable post-process. The presence of smut as solid residues on such types of chemical treatments has been also analyzed with XRF and ICP-MS techniques. The results obtained show that Si and Mg precipitates are removed from the metal surface at the last step of the investigated post-process. The percentages of the elements decrease from 25.0% to 8.09% Si and from 0.86% to 0.42% Mg, achieving the alloy smut-free composition on the metal surface. Tensile strength measurements have shown that the post-process described not only maintains the mechanical properties of the bulk material but, in comparison with non-post-processed parts, a slight improvement is observed with respect to the initial values, Young modulus (61.1 GPa to final 62.2 GPa), yield strength (from 236.8 to 246.7 MPa), and tensile strength (from 371.9 to 382.5 MPa) is observed, suggesting that the post-process has positive impact on the printed metal part.