Heavy Metals Research Articles

New challenges regarding the environmental and sanitary condition of Ukrainian water bodies

Today Ukraine is faced with new challenges that have a significant impact on natural water bodies and aquaculture. As a result of hostilities, there is an additional pressure on aquatic ecosystems. Unfortunately, large territories with important fishery complexes of Ukraine are either occupied, located in the war zone, or mined. Currently it is impossible to carry out comprehensive monitoring investigations into the actual environmental condition of inland water bodies of Ukraine. Therefore, in order to establish a true picture of the state of the water fund of Ukraine, an analytical review of publications was performed. Unfortunately, after the large-scale hostilities on the territory of Ukraine, a significant number of water bodies changed their status according to saprobic indicators. The situation is difficult with the reservoirs of the Dnipro River Cascade, which accumulate all pollutants released into the water from the catchment area. The destruction of the Kakhovka Hydroelectric Power Station led to a massive killing of all biota, including fish. The reservoirs are mostly polluted by biogenic, organic and surface-active substances, oil products, phenols, pesticides, and heavy metals. Even in the pre-war period, the problem of water pollution required immediate decisions, and with the beginning of the full-scale war, it became one of the most urgent tasks for Ukraine. Today, Ukraine’s water bodies suffer from pollution by pyrogens, fuel, and lubricants after rocket attacks and even from the total destruction of fish farms, water reservoirs, i.e., the Kakhovka Reservoir. Therefore, monitoring of the environmental condition of inland water bodies of Ukraine will provide an opportunity to assess their real condition and, in the future, to select the complex of methods aimed for their restoration.

A comprehensive assessment of gold leaching wastewater through pollution and water quality indices. Case study: Small scale extraction facilities in the department of Caldas—Colombia

This study introduced a comprehensive methodology (the Six-Indices method for Water Pollution Assessment) to evaluate the quality of gold leaching effluents. Sampling was conducted for 14 months in small-scale gold mining facilities in the department of Caldas, Colombia. 23 physicochemical parameters were selected based on environmental regulations, standards of use for agricultural purposes and WHO recommendations. They covered general characteristics of effluents and critical inputs of the leaching process. 15 (pH, COD, TSS, CN−, Cl−, SO42−, S2−, Cd, Zn, Cu, Cr, Fe, Ni, Ag, and Pb) of them exceeded permissible limits. Multivariate statistical analysis (Person's correlation and hierarchical clustering analysis) and six Wastewater Quality Indices (WWQIs: Arithmetic Weighted Water Quality Index, WAWQI, Synthetic Pollution Index, SPI, Index of Water Pollution, WPI, Comprehensive Pollution Index, CPI, Heavy Metal Pollution Index, HPI, and Degree of Pollution, Cd) were used to comprehensively assess the effluent contamination. Key pollutant interactions (hydrocarbons & fats and oils, Zn & CN−, Cu & Cl−, as well as CN− & COD & SO42−) were revealed guiding targeted mitigation strategies. CN− and heavy metals were the main pollutants, posing serious environmental risks due to their high levels. The calculated HPI value was above the critical level of 100, indicating that the artisanal gold leaching operations in the studied area could be hazardous to human health. This study provides a starting point for developing effective and sustainable strategies to manage wastewater in mining regions in Colombia and other areas with similar mining practices.

A Study on Removal of Heavy Metal Ions by MgFe-Layered Double Hydroxides

Heavy metal pollution has posed great threats to the ecological environment, food security and human health. To date, various approaches have been explored, among which mineralization of heavy metals via layered double hydroxides (LDHs) are reported as a promising way to solve the addressed issue. In line with this, the current study attempts to the fabrication of two typical MgFe-LDHs containing different intercalated anions (denoted as MgFe-CO3 and MgFe-NO3) for mineralization of Cd2+. In the experiments, the as-prepared MgFe-NO3 exhibited a high maximum adsorption capacity of 444.44 mg/g, which was 2.82 times higher than that of the contrast sample MgFe-CO3 (157.48 mg/g). Such difference in adsorption capacity can be attributed to the different mineralization mechanism: For MgFe-NO3, the mineralization process was dominated by isomorphous substitution and the CdFe-LDH was the main product, while for MgFe-CO3, the formation of CdCO3 can be observed. This work paves a way in treating Cd2+ by MgFe-NO3 through super-stable mineralization and its further application in the removal of co-existent Cd2+ and AsO43- ions can be expected.

Potential of Selected Species of Spiraea L. for Phytoremediation of Heavy Metals from Soils of Urban Areas

Four taxa of Spiraea were selected for this study: S. × cinerea Zabel ‘Grefsheim’, S. nipponica Maxim. ‘Snowmound’, S. splendens É. N. Baumann ex K. Koch and S. × vanhouttei (Briot) Carrière growing for a minimum of 5 years along heavily trafficked traffic routes. This study included the genus Spiraea due to its popularity in horticultural practice (commercial availability, widespread in urban environments). In addition, the use of ornamental shrubs for phytoremediation in urban green spaces effectively combines the aesthetic needs of residents with those of caring for the urban environment. This study was conducted in Poznań (population 550,000, the fifth largest city in Poland). Soils and foliage were examined in spring and autumn. Soil pH and specific electrolytic conductivity (EC) were determined. The content of micronutrients (Cu, Fe, Mn, Ni, Zn) and toxic heavy metals (Cd, Cr, Pb) in soil dry matter and leaves was determined. The uptake capacity of bioavailable forms of heavy metals by Spiraea from the soil was analyzed by determining the bioconcentration factor (BCF). It was found that the studied taxa meet the basic requirements for plants used for soil phytoremediation processes, especially for chromium phytoextraction. The degree of salinity of the tested soils did not pose a threat to the shrubs growing there, and most of the sites, despite the alkaline reaction, are suitable for their cultivation. S. × cinerea and S. × vanhouttei have BCFs for lead <1. The remaining taxa are characterized by strong concentrations of all analyzed elements. A particularly high BCF, above 10, was recorded for chromium and high for manganese and nickel.

Bibliometric Analysis of Reference Materials and Certified Reference Materials Applied to Geochemistry

The use of reference materials (RMs) and certified reference materials (CRMs) is essential to guarantee the reliability of measurement procedures ‐ a major factor motivating the efforts of the geoanalytical community. This work quantifies trends and patterns in the scientific literature concerning RMs and CRMs in geochemistry for specific timespans, with the aim of evaluating historical developments, research fields, geographic shifts of research centres, and current trends. The Scopus database was surveyed for peer‐reviewed full‐texts (14,201 documents), which were subsequently exploited for statistical description, bibliometric mapping and cluster analysis. Mineral exploration and trace element geochemistry stimulated early research, whereas environmental subjects have grown in importance mainly since the year 2000. International standardisation was coincident with an increase of publications covering CRMs and geochemistry, and is thought to reflect the impact of ISO guidelines in this scientific activity. Other factors include investments in research facilities, creation of specialised geoanalytical journals and organisation of international meetings. The analysis shows that RMs are typically used for petrogenetic research topics, whereas CRMs are equally important for environmental sciences, chemistry and geosciences. Environmental sciences are mostly concerned with anthropogenic contamination of ecosystems by heavy metals, whereas geological interest is mainly driven by isotope geochemistry. Scientific frontiers in geoanalytical research comprise microanalytical methodologies, unconventional isotopes, rare earth elements and environmental monitoring. New trends in CRM applications also include biogeochemistry and radionuclides.

A Novel Landfill Liner Material for Solidified Lake Sediment Based on Industrial By-Product and Construction Waste: Engineering Behavior and Cr(VI) Breakdown Characteristics

Engineering sludge, industrial waste, and construction waste are marked by high production volumes, substantial accumulation, and significant pollution. The resource utilization of these solid wastes is low, and the co-disposal of multiple solid wastes remains unfeasible. This study aimed to develop an effective impermeable liner material for landfills, utilizing industrial slag (e.g., granulated blast furnace slag, desulfurized gypsum, fly ash) and construction waste to consolidate lake sediment. To assess the engineering performance of the liner material based on solidified lake sediment presented in landfill leachate, macro-engineering characteristic parameters (unconfined compressive strength, hydraulic conductivity) were measured using unconfined compression and flexible wall penetration tests. Simultaneously, the mineral composition, functional groups, and microscopic morphology of the solidified lake sediment were analyzed using microscopic techniques (X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy + energy dispersive spectroscopy). The corrosion mechanism of landfill leachate on the solidified sediment liner material was investigated. Additionally, the breakdown behavior of heavy metal Cr(VI) within the solidified sediment liner barrier was investigated via soil column model experiments. The dispersion coefficient was computed based on the migration data of Cr(VI). Simultaneously, the detection of Cr(VI) concentration in pore water indicated that the solidified sediment liner could effectively impede the breakdown process of Cr(VI). The dispersion coefficient of Cr(VI) in solidified sediments is 5.5 × 10−6 cm2/s–9.5 × 10−6 cm2/s, which is comparable to the dispersion coefficient of heavy metal ions in compacted clay. The unconfined compressive strength and hydraulic conductivity of the solidified sediment ranged from 4.90 to 5.93 MPa and 9.41 × 10−8 to 4.13 × 10−7 cm/s, respectively. This study proposes a novel approach for the co-disposal and resource utilization of various solid wastes, potentially providing an alternative to clay liner materials for landfills.

Analysis of the Physical and Chemical Composition of Sludge from the Water Treatment Plant

The properties and composition of the sludge generated in water treatment systems depend primarily on the type and composition of the water to be treated, the treatment methods, and the type and doses of chemical reactants. The sludge produced in the water treatment plant (WTP) under study follows the technological processes of coagulation, flocculation, sedimentation, and filtration. The analyses aimed to characterize the sludge in terms of its physico-chemical properties and classify it in terms of its potential discharge into the river and management. Four series of sediment tests were conducted over a calendar year (March, June, September and December), analysing selected parameters using various test methods, including the X-ray crystallography (XRF) method. The publication's authors showed that the sediment consists mainly of sand, clay, and silt particles with grain sizes ranging from 0.001 mm to 1 mm. Silica (53.78%), alumina (23.58%), calcium oxide (8.28%), iron (III) oxide (5.61%), and potassium oxide (2.36%) represent the main chemical constituents present in the sediment. The authors characterized the sediment in terms of the content of biogenic compounds: various forms of phosphorus and nitrogen, organic compounds – determined as total organic carbon (TOC), selected metals, and the content of individual elements (carbon, hydrogen, oxygen, nitrogen, sulfur). In addition, the sludge samples were also characterized in terms of calorific value, ash content, water content, and heat of combustion. Discharging WTP sludge into rivers, ponds, and lakes or storing dewatered sludge is an environmentally unfriendly form of disposal for this type of waste. The authors see the possibility of conducting further research on using WTP sludge in wastewater treatment, removing heavy metals from aqueous solutions, producing cement and construction materials, and recovering or recycling.

Evaluation of heavy metal contamination: an analogy between conventional techniques and paper microfluidics as the futuristic probe for diverse environmental matrices

Evaluation of heavy metal contamination: an analogy between conventional techniques and paper microfluidics as the futuristic probe for diverse environmental matrices

Exploring formation of Quark-Gluon Plasma through two-particle correlations functions in A+A and p+p data

This paper is the result of team’s hard work, which delves into the correlation functions in proton-proton and PbPb(Lead-Lead) collisions, scrutinizing their relevance in the formation of quark-gluon plasma. This project first simulated these high-energy collisions and generated a comprehensive dataset of proton-proton and PbPb(Proton-Proton) interactions. The entire analysis is designed around the task of calculating azimuthal and pseudorapidity correlation functions, and wish to compare the differences and similarities between the two collision types. Also delved into these correlation functions in proton-proton collisions as potential evidence for QGP(Quark-gluon plasma), a type of matter typically found in heavy metal collisions such as Pb-Pb. The results reveal unique patterns lurking in the correlation functions that suggest that QGPs may form even in smaller collision systems. Also Quark-Gluon Plasma (QGP) is a state where quarks and gluons move freely at extremely high energy densities. The two-particle correlation function helps identify QGP by measuring how particles are correlated after a collision. Specific patterns in these correlations, like a “ridge” structure, indicate the collective behavior of particles, signaling the formation of QGP. These findings are expected to shed more light on the intricate dynamics in particle collisions and the specific conditions that lead to the formation of QGPs.

The Role of Organic Amendments and Their Impact on Soil Restoration: A Review

Soil organic matter (SOM) plays a pivotal role in maintaining soil health by enhancing its physical, chemical, and biological properties. It improves soil structure, water retention, nutrient availability, and microbial activity, contributing significantly to sustainable agriculture. Organic amendments, including animal manure, compost, biosolids, crop residues, and various organic by-products, are widely used to restore degraded soils by increasing SOM content. These amendments not only supply essential nutrients but also promote biological aggregation, suppress soil-borne pathogens, and improve soil's resistance to environmental stressors such as drought and heavy metal toxicity. The positive impacts of organic amendments on soil properties are well-documented, with key benefits including increased soil organic carbon (SOC), improved nutrient cycling, enhanced microbial diversity, and greater water-holding capacity. Organic materials such as compost and animal manure have been shown to significantly improve soil fertility and restore degraded soils. The application of green manure and crop residues also boosts soil biodiversity, enhances rhizospheric processes, and supports overall ecosystem resilience. This paper emphasizes the importance of adopting holistic soil management practices that include organic amendments, conservation tillage, and sustainable cropping systems to address soil degradation. By focusing on replenishing SOM, improving nutrient availability, and increasing soil biodiversity, these practices can contribute to the long-term sustainability of agricultural systems and environmental health. The restoration of soil organic matter is essential for enhancing soil quality and mitigating degradation, ultimately ensuring food security and ecosystem stability for future generations.

Epoxidation of Chalcone Derivatives under Visible-Light Irradiation: An Organophotoredox Catalytic Approach

AbstractEpoxidation of α,β-unsaturated ketones under visible-light irradiation constitutes a significant chemical transformation with potential applications in the synthesis of epoxypropane derivatives. An organophotoredox catalytic system is herein reported to facilitate efficient aerobic epoxidation. This protocol enables the conversion of α,β-unsaturated ketones into their corresponding epoxy products with moderate to high yields under benign reaction conditions. The methodology demonstrates broad functional-group compatibility, providing a reliable and direct route to a variety of functionalized epoxypropane compounds. Additionally, the absence of heavy metals in this strategy renders it particularly suitable for the pharmaceutical industry, offering a new avenue for the synthesis of epichlorohydrin drugs.

Prediction of Spatiotemporal Pollution of Soil Heavy Metal in Mining Areas Based on Grey Neural Network Algorithm

Prediction of Spatiotemporal Pollution of Soil Heavy Metal in Mining Areas Based on Grey Neural Network Algorithm

Unveiling the composition of bio-earth from landfill mining and microplastic pollution.

Landfill mining is the prominent solution for the recovery of resources from legacy waste. The bio-earth recovered from landfill mining is being utilized for a variety of applications like application as fertilizer. The presence of microplastic in the recovered bio-earth disrupts its usefulness. This study investigated the composition and microplastic pollution in bio-earth derived from landfill mining at the Bhandewadi landfill, Nagpur, India. Results provided insights into its characterization and presence of microplastic. The average moisture content of the bio-earth was 25.2 ± 1.1% with total organic carbon of 14.3 ± 0.6%. The bio-earth exhibited a C:N ratio of 16.9 ± 5.0, volatile solid content of 24.6 ± 1.0%, and ash content of 75.4 ± 1.0%. Bulk density was 434.3 ± 37.2kg/m3, pH value 6.91 ± 0.28, and electrical conductivity 4.6 ± 0.7 dS/m. Total nitrogen content was 0.9 ± 0.3%, available phosphorus 2.1 ± 0.3g/kg, and potassium and sodium contents of 12.7 ± 0.4g/kg and 3.9 ± 0.3g/kg, respectively. Heavy metals detected included Fe, Zn, Mn, Cu, Pb, Ni, Cr, and Cd. Microplastics in the bio-earth samples were assessed using attenuated total reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR). The amount of microplastics averaged 100,150 ± 29,286 items per kg (dry basis). Additionally, five specific polymer types were prominent as microplastics. Further research and mitigation strategies are necessary to ensure the safe and sustainable use of bio-earth in agriculture and horticulture.

Ozonation combined to BAC filtration for secondary effluent treatment containing moderate concentration of heavy metals

The treatment of industrial and urban effluents is a recognized strategy for environmental preservation, which brings benefits not only to fauna and flora but also to human health. In this paper, the combination effect of ozonation (O3) and biological activated carbon (BAC) filtration treatments on the inorganic contaminants removal, disinfection, and mitigation of toxicity in secondary effluent from wastewater treatment plants (WWTP) were evaluated. Disinfection efficiency was evaluated using total coliforms and Escherichia coli inactivation, and toxicity was investigated by Eruca sativa germination, Artemia salina larvae and Daphnia similis. The O3-BAC system was efficient to remove metals, disinfect the samples and reduce toxicity. The combined treatment reduced 99.9 % of the assessed metal concentration and ≥ 96 % on samples enriched with 2x the concentration allowed by Brazilian legislation. O3-BAC also demonstrated superior bactericidal performance compared to BAC and O3 alone, exhibiting a 5-log reduction within 24 h against total coliforms and 4-log reduction in E. coli, whereas BAC and O3 achieved ≤ 3-log inactivation. Regarding toxicity, the bioassays demonstrated that the combined treatment effect improved the relative germination of E. sativa (∼97 %), and the relative root elongation showed no differences compared to the control group (∼100 %). Similar behavior was also observed in the analysis with wheat and radish seeds, with no differences noted between the treated samples and the positive control. In relation to A. salina, no toxic results were observed even at high metals concentration. Additionally, BAC treatment reduced D. similis immobilization from 97 ± 6 % to a level with no observed effect. The observed synergy suggests that the O3-BAC combination may address a variety of pollutants and improve treatment efficacy.

Synergistic effects of carbon coating and Bi-bridge in S-scheme C@CuO/Bi/Bi2MoO6 nanocomposites for enhanced photoreduction of Cr(VI)

The S-scheme mechanism in photocatalysis offers a promising approach to significantly enhance photoreductive activity. Here, using Bi dots as electronic media, and by changing the amount of added C@CuO on the surface of flower-shaped Bi2MoO6, a diverse range of CBM-x heterojunctions, were synthesized using a multi-step approach that incorporated solvothermal preparation and calcination methods. CBM-10 exhibited excellent photocatalytic activity: 96.9 % of Cr(VI) removal in 30 min, which was 38.0-fold better than CuO, 4.2-fold higher than pristine Bi2MoO6. Furthermore, even after five cycles of use, CBM-10 showed outstanding stability. Experiments to capture the active species revealed that electrons play a crucial role in the photocatalytic reduction of Cr(VI). In these heterojunctions, carbon doping leads to the formation of coatings on the semiconductor materials to promote the migration and separation of photogenerated carriers. The presence of carbon coating is beneficial to improve the stability of CBM-10. Bi dots grown on Bi2MoO6 nanosheets can act as electron transport channels in C@CuO/Bi/Bi2MoO6, accelerate photoinduced carrier separation. The internal electric field, and the existence of “S-scheme” charge transfer mechanism was verified by the combination of atomic force microscope and synchronous illumination X-ray photoelectron spectroscopy. This process significantly mitigates the recombination of photo-induced carriers, enhancing the overall photoreduction efficacy. This study presents a novel method for developing S-scheme heterojunction to enhance the effectiveness of Cr(VI) decontamination, paves a promising route to heavy metal removal by mild photo-reductive system, and provides new insights into the design of photocatalysts with enhanced redox capabilities.

Moss Technique Used to Monitor the Atmospheric Deposition of Trace Elements on the Territory of the Ryazan Region, Russia

Instrumental neutron activation analysis in combination with the method of moss biomonitoring for the assessment of atmospheric deposition of heavy metals and other elements was applied for the first time in the Ryazan Region in Russia. Concentrations of 42 macro, micro and trace elements in 63 moss samples (Hylocomium splendens and Pleurozium schreberi, as well as Hypnum cupressiforme, Sciuro-hypnum sp., Plagiothecium sp. and Ptilium sp.), collected on a relatively uniform grid in the study area, were determined. On the basis of analytical results using GIS technologies, maps of the spatial distribution of heavy metals and other toxic elements were constructed for the Ryazan region. The method of multivariate statistical analysis (factor analysis) was used to identify the main sources of pollution—large industrial facilities located in this region. The obtained results were included in the Atlas of Atmospheric Deposition of Heavy Metals, which is published by the UN Commission on Long-Range Transboundary Air Pollution (UNECE ICP Vegetation).

Assessment of heavy metal ecological risk in typical seagrass beds of the China Yellow Sea

Assessment of heavy metal ecological risk in typical seagrass beds of the China Yellow Sea

Investigation of Lead, Nickel, and Cadmium Levels in Urine Samples of Healthy and Patients with Kidney Failure in Al-muthanna Governorate, Iraq

Background: The Iraqi ecosystem, particularly in the southern area, has been polluted due to human activity. Analyzing biological materials is the most common method for detecting the presence of toxic substances in the human body. Method: Heavy metal levels of Pb, Ni, and Cd in urine specimens collected from individuals with renal failure and healthy individuals residing in Al-Muthanna province were measured by using atomic absorption spectroscopy. Urine Specimens were collected from two cohorts of male and female participants: the group of individuals with renal failure and the group of individuals who are in good condition. The specimens of urine from both the group of patients with renal failure and the group of healthy individuals were taken from the Al-Muthanna governorate in southern Iraq. This governorate served as a focal point for extensive military operations throughout the Gulf War. Results: The concentrations of toxic substances (Pb, Ni, and Cd) in the urine specimens of the cohort of patients suffering from renal failure are 0.411, 0.197, and 0.113 mg/l, respectively. Concentrations of (Pb, Ni, and Cd) in the healthy group are 0.249, 0.101, and 0.0294 mg/l, respectively. The toxic metals found in urine samples can be organized in the following order: Pb > Ni > Cd. Conclusion: The findings indicated that the concentrations of toxic substances in specimens of urine from individuals with renal failure are considerably greater than those in the control group of healthy individuals. According to the findings, patients' incidence of renal failure may be related to the prevalence of harmful compounds in southern Iraq.

Effects of Tin Mining on Water Sources in Mwerasandu Tin Mine, Ntungamo District, Uganda

Tin mining is a widespread economic activity across various regions worldwide. Understanding the consequences of such operations is crucial for sustainable water management and environmental conservation. The current study aimed at determining the concentrations tin, lead and mercury in the water sources of Nyakahiimbura Stream in Mwerasandu, and assessed the physico-chemical properties including pH, turbidity, and chemical oxygen demand (COD) of the water from the Nyamuhimbura stream, Ntungamo district. Water samples from three locations, that is; the upstream, impact area and downstream of the Nyakahiimbura water stream were collected during the dry and wet seasons of the year 2024. The samples collected were analyzed for the physico-chemical properties in the laboratory while the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP – OES) was used to determine the concentration of heavy metals in the water samples. The pH, COD values obtained were within the acceptable effluent standards while the turbidity values at the upstream and downstream of the dry season and downstream during the wet season were above the acceptable effluent Standards. The tin concentration was high in the dry season (0.09mg/L) as compared to concentration (0.118mg/L) in the wet season. Lead concentration was the same (0.015mg/L) in both seasons. The concentrations of the heavy metals showed some variations in both dry and wet seasons in the upstream, impacted area and the downstream of the study area as compared to the values of the effluent standards. The study recommends that alternative sources of water for domestic use should be sought of. Also, the government officials especially from the Ministry of Health should carry out awareness campaigns to members of the community about the health risks associated with the uptake of the contaminated waters for domestic purposes. Constructed wetlands should be in place around the mining sites to act as filters for the dangerous metals before the water enters the surrounding environment.

Removal of Heavy Metals from Wastewater By The Membrane-Adsorbent System With Different Running Methods

Removal of Heavy Metals from Wastewater By The Membrane-Adsorbent System With Different Running Methods