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Prolonged use of the chromate [Cr(VI)]-contaminated water originates severe health problems for the public. Thus, the societal urgency is a reusable and cost-effective material for efficient scavenging of Cr(VI) from contaminated industrial wastewater. Aiming this, we had targeted to prepare some cheap and effective materials for scavenging Cr(VI) from the contaminated water. Herein, we report the preparation of hydrous cerium-copper oxide (HCCO) with some tailored compositions and employed toward the abstraction of chromate from water solution. The HCCO (Ce: Cu = 1:4, mole/mole) has shown the highest Cr(VI) scavenging capacity. Experimentally, highest Cr(VI) abstraction efficiency is recorded at pH ~ 3.0 (508.853 mg. g−1 at 303 K). Kinetically, the Cr(VI) scavenging reaction with HCCO surfaces agrees better with the pseudo second-order model (R2 = 0.987) equation and the equilibrium Cr(VI) distribution data explain the Freundlich isotherm model (R2 = 0.998) equation, which anticipates the multi-layered adsorption on heterogeneous sites of the adsorbent. A negative value of the Gibbs free energy change indicates that the Cr(VI) adsorption over HCCO surfaces is spontaneous. The positive enthalpy change indicates the endothermic nature of the said reaction. HIGHLIGHTS: One-pot synthesis of hydrous Ce(IV)-Cu(II) oxide (HCCO) and characterizations. Systematic Cr(VI) scavenging from modeled ground water with HCCO. Best fit pseudo-second-order kinetic model, implying the chemisorption mechanism. Very high amount of Cr(VI) scavenging at ambient condition reported to be 508.85 mg.g−1. Coulombic interaction between HCCO and Cr(VI) is responsible for scavenging Cr(VI). [ABSTRACT FROM AUTHOR]

Consumer demand for healthier and more sustainable foods has led to a multitude of innovative food products. The aim of the work was to monitor the physico-chemical quality parameters (color, taste, smell, infestation, granularity, humidity, gluten index, falling number, alveographic properties, ash content, hectoliter mass of wheat) for the raw material: wheat, for the flours resulting from the milling, and for different types of flours and resulting mixtures. The mixtures were made with wheat flour and carob, oats, rice, buckwheat, and coconut flour added in proportions of 5%, 10%, and 20%. Heavy metals (Pb, Cd, Zn, and Cu) were also determined for different types of flour. The metal content was determined by the atomic absorption method using a GBC Avanta PM atomic absorption spectrometer. The detection and quantification limits were evaluated using calibration curves. The degree of coloring of the flours differs depending on the degree of extraction and, therefore, also depends on the amount of ash contained. As for infestation contamination, it was not identified in any of the analyzed flour. Rheological properties indicate the quality of flours. Flour types 480 and 550 recorded exceptional values of the rheological parameters, presenting a deformation energy (W) above 200 10-4J and a curve configuration ratio (P/E) of 1.08. The metal concentrations were between the permissible limits defined by the FDA/WHO. [ABSTRACT FROM AUTHOR]

Every year, the problem of environmental pollution from metallurgical waste is gaining momentum. In particular, these are metallurgical wastes containing residual metals. However, with the help of innovative methods of processing lead-containing slags, they can be turned into valuable resources with minimal impact on the environment. This article discusses the importance of recycling lead-containing slag and describes various methods of recycling. The scientific novelty of the article is to analyze the influence of the content of toxic metals, such as lead, chromium, zinc, and copper, in the products obtained after roasting around the waste storage. The results of the optimization of experimental data allowed to specify the composition of the mixture temperature of the process of ignition of residual and corrosion-protective metals chromium and nickel, with the indicators of dependencies in the three-dimensional model. The results of the mathematical planning of the processing of waste slag and galvanic sludge showed that the recovery of lead reached 93-95%, chromium-94-96% nickel-93%, and copper-90%. The obtained product is identified as a composite material by its elemental composition and microstructure. In the general structure of the surface, firing products are characterized by the presence of the aluminosilicate minerals melilite, merwinite, and ockermanite, as well as calcium monosilicates, in the form of irregular forms of light gray lamellar crystals. [ABSTRACT FROM AUTHOR]

The growing mining industry has led to environmental pollution, primarily from mining waste known as acid mine drainage (AMD). To effectively address AMD, a combination of constructed wetland and biochar treatment is necessary. This study aims to assess the ability of biochar in combination with wetland sediment to reduce sulfate and cadmium (Cd) heavy metals in AMD. The research method involved a laboratory-scale constructed wetland in a microcosmos and a treatment of: T1, biochar mixed with wetland sediment; T2, sediment; T3, biochar; and T4, control with no treatment. Observations included sulfate content, pH determination, heavy metal concentration, and scanning electron microscope (SEM) analysis of the biochar. Results after 30 days of observation showed that T1 reduced sulfate concentration by 72.03%, compared to 63.33% for T2, 63.33% for T3, and 2.50% for T4. The reduction in sulfate was accompanied by a consecutive increase in pH, with T1 at pH 6.9, T2 at pH 6.6, T3 at pH 6.4, and T4 at pH 3.6 after 30 days. T1 treatment reduced heavy metal Cd by 80.16% after 30 days, while T2 of 55.46%. T3 of 65.83% and T4 of 2.31%. This indicates that the constructed wetland method, combined with biochar, is more effective in reducing sulfate and the heavy metal Cd in AMD, compared to using only biochar or wetland sediment treatment. [ABSTRACT FROM AUTHOR]

Heavy metal stress can lead to slow growth and dwarfing of hyperaccumulators, limiting their effectiveness in remediating soil heavy metal pollution. Nitrogen (N) and phosphorus (P) fertilization can enhance plant growth, biomass, and stress resistance. We hypothesize that N and P fertilization could improve the soil heavy metal remediation efficiency of Bidens pilosa (B. pilosa). We conducted a greenhouse experiment with four treatments: control (CK), nitrogen fertilization (NF), phosphorus fertilization (PF), and nitrogen and phosphorus fertilization (NPF). Then, we analyzed the growth status, heavy metal content, and accumulation of B. pilosa under various treatments to explore the impact of N and P fertilization on its potential to remediate soil heavy metal pollution. The shoot height, root length, and shoot biomass of B. pilosa significantly improved under NF and NPF treatments (P<0.05). The root tolerance index of B. pilosa in the NF and NPF treatments also increased, exceeding 1. The NF and NPF treatments significantly increased the accumulation of heavy metals Cd, Cu, and Pb in the shoots of B. pilosa ( P<0.05). The transfer coefficient of these heavy metals also increased in the NF and NPF treatments. Accordingly, N and NP fertilization can promote the growth of B. pilosa, increase the accumulation of heavy metals Cd, Cu, and Pb in B. pilosa, and improve the remediation efficiency of these heavy metals. In the context of rising global soil heavy metal pollution, our findings indicate that B. pilosa can aid in the remediation of soil heavy metal pollution. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is one of the most important staple food crops, and its sustained production and nutritional security have attracted much attention. Cadmium, a heavy metal toxic to plants and humans, can enter wheat in various ways. Foliar fertilization can reduce the cadmium content in plants, but how different fertilizers reduce the cadmium toxicity of plants is still unclear. In this study, the effects of foliar application of fertilizers on spring wheat yield, cadmium accumulation, and trace element contents were studied by applying three kinds of fertilizers (multi-element compound fertilizer, manganese-zinc micro fertilizer, and foliar silicon fertilizer) to spring wheat planted in mildly and moderately cadmium polluted areas. The results showed that the yield of wheat when fertilized with multi-element compound fertilizer, manganese-zinc micro fertilizer, and silicon fertilizer increased by 17.1%, 15.7%, and 16.9%, respectively, compared with the control. In addition, all three foliar fertilizers reduced the cadmium content in wheat grains to below the standard value of food pollutants (≤0.1mg/kg), and significantly reduced the transport of cadmium from glume to grain, among which manganesezinc micro fertilizer had the best effect, with a cadmium reduction rate of 41.7%. At the same time, manganese-zinc micro fertilizer significantly increased the absorption of trace elements in wheat organs. These results indicated that the foliar application of manganese-zinc micro fertilizer could be an effective way to increase wheat yield, inhibit cadmium accumulation, and increase nutrient absorption in mildly to moderately cadmium-polluted areas. [ABSTRACT FROM AUTHOR]

Heavy metal contamination in surface water is a worldwide concern. Being the primary source of river pollution, the wastewater drains bring agricultural and domestic waste into the rivers. The present study was carried out to evaluate levels of heavy metals from wastewater drains of River Ghaggar in Punjab (India). The water samples were collected in five different seasons to carry out this work. The concentration of five metals (lead, cadmium, iron, aluminium, and nickel) was determined through Microwave Plasma-Atomic Emission Spectroscopy (MP-AES) technique. The data were interpreted through various environmental and human health risk assessments. The results of the current study revealed that lead, iron, and aluminium exceeded the permissible limit of the Central Pollution Control Board (India). Pollution indices such as the heavy metal pollution index (HPI), heavy metal evaluation index (HEI), water pollution index (WPI), and degree of contamination (Cd), suggested enormous heavy metal contamination in the study area. Human health risk assessment also revealed that people dwelling near these drains are highly prone to cancer disease and hazard quotients were observed above the threshold limit that poses high non-carcinogenic risks. Based on the current study, recommendations are made for water quality improvement in the wastewater drains of Punjab. These drains are further responsible for enhancing pollution in the main rivers in the State of Punjab and heavy metal pollution also poses several environmental and health risks. The compiled data during the present study provides a baseline model that can be helpful in resource management for government authorities of Punjab state. [ABSTRACT FROM AUTHOR]

Heavy metal oxides (HMOs) can enhance the physical, optical, and radiation shielding properties of glass. Through the comprehensive consideration of the absorption edge, the fast neutron removal cross-section, and transmittance of heavy metal oxides, the rapid determination of the shielding material system is achieved. Herein, B 2 O 3 –TeO 2 –BaO-MO (M = Bi, W, Cd, Mo) glasses are synthesized by the melt quenching method, and the effects of various heavy metal oxides on the glass performance are investigated. The physical and optical property results show that the addition of Bi 2 O 3 provides glass with greater stiffness, a more densified glass network, and a relatively wide indirect optical bandgap compared to other oxides. Subsequently, the photon attenuation behavior of the B 2 O 3 –TeO 2 –BaO-MO glasses was evaluated using the MCNPX, Phy-X and XCOM. Compared to the shielding materials in service, all the four metal oxide glasses exhibit excellent shielding capabilities against X-rays, gamma rays, and fast neutron. Particularly, due to the higher density and effective atomic number of Bi 2 O 3 , its modified glass will have more extra-nuclear electrons per unit volume, which increases the probability of collision with incident photons, and thus exhibits superior radiation shielding properties than other glasses. The Bi 2 O 3 -modified glass exhibits an average specific lead equivalent of 0.441 mmPb/mm in the medical X-ray energy range (0.03–0.08 MeV), and only requires a thickness of 0.8 cm to achieve complete protection against this incident photon, which far exceeded the specific lead equivalent requirement of 0.22 mmPb/mm for "protection devices against diagnostic medical X-radiation". [ABSTRACT FROM AUTHOR]

Harbors on all coasts regularly silt up, receiving sedimentary inputs that progressively reduce the water depths available for navigation. Consequently, they are routinely dredged to guarantee the depths necessary for navigation. Sediments act as a reservoir for anthropogenic contaminants such as heavy metals and persistent organic pollutants (POPs) that enter the aquatic system associated with particles or in solution. The objective of this study is to assess the state of pollution by POPs and heavy metals such as copper and zinc, used in large quantities in antifouling paints, in the sediments of the port of Oran. These were characterized by different methods: size, XRD, calcination, FTIR, NMR, GC–MS, and AAS, in order to determine their main characteristics and heavy metals and POPs content. The particle size is determined by laser particle size distribution. Thus, sediments from Oran port are composed of means and end sands, silt, and clay. The XRD analysis shows that the sediments consist mainly of silicates and calcite. The organic matter was determined by ignition loss at 450 and 550 °C; it is about 7%. Analysis by FTIR, 1H and 13C NMR, and GC–MS of POPs excerpts shows that the sediments are highly polluted by aliphatic and aromatic hydrocarbons (3372 mg/kg). Finally, metals were determined by AAS method. The results show significant pollution of Zn (313.5 mg/kg) and moderate pollution by Cu (75.6 mg/kg). [ABSTRACT FROM AUTHOR]

Reservoir is easy to be polluted by nutrients and heavy metals in the surrounding soil. There is a close relationship between heavy metals and nutrients in soil. Nutrient salts will affect the activity of heavy metals, and heavy metal pollution will affect plant growth and nutrient salt absorption, thus affecting ecosystem health. This study was performed to evaluate nutrients (TN, TP) and heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in the upper watershed of Xiashan Reservoir by the enrichment factor, the geoaccumulation index, the enrichment factor and leaching experiments. The results showed that the average enrichment of TN and TP reached the level of moderate pollution. The nutrient enrichment of different sampling sites increased gradually from south to north, which may be affected by the topography of the study area. The comprehensive trophic level exceeds the criteria for a state of severe eutrophication of water bodies, which may lead to the enrichment of nitrogen and phosphorus in the water body through processes such as runoff. Evaluation of the geoaccumulation index and potential ecological risk index revealed that the soil was primarily contaminated by Cd and Hg, which are in the level of considerable potential ecological risk and high potential ecological risk. So most attention should be paid to Cd and Hg pollution. Pollution control of heavy metals in soil is a priority because they are more difficult to leach than nutrients. This study provided an insight into the nitrogen and phosphorus control and heavy metal pollution management in the upper watershed of Xiashan Reservoir. [ABSTRACT FROM AUTHOR]

The biogeochemical cycles of trace elements are changed by fire as a result of the mineralization of organic matter. Monitoring the accumulation of trace elements in both the environment and the tree biomass during the post-fire (PF) forest ecosystem regeneration process is important for tree species selection for reforestation in ecosystems under anthropogenic pressure. We analyzed the soil concentrations of different groups of potentially toxic elements (PTEs), including beneficial (Al), toxic (Cd, Cr, Pb), and microelements (Cu, Mn, Ni, Zn), and their bioaccumulation in the tree species (Pinus sylvestris, Betula pendula, Alnus glutinosa) biomass introduced after a fire in a forest weakened by long-term emissions of industrial pollutants. The results indicated no direct threat from the PTEs tested at the PF site. The tree species introduced 30 years ago may have modified the biogeochemical cycles of the PTEs through different strategies of bioaccumulation in the belowground and aboveground biomass. Alder had relatively high Al concentrations in the roots and a low translocation factor (TF). Pine and birch had lower Al concentrations in the roots and higher TFs. Foliage concentrations and the TF of Cd increased from alder to pine to birch. However, the highest concentration and bioaccumulation factor of Cd was found in the alder roots. The concentrations of Cr in the foliage and the Cr TFs in the studied species increased from pine to birch to alder. Higher concentrations of Cu and Ni were found in the foliage of birch and alder than of pine. Among the species, birch also had the highest Pb and Zn concentrations in the roots and foliage. We found that different tree species had different patterns of PTE phytostabilization and ways they incorporated these elements into the biological cycle, and these patterns were not dependent on fire disturbance. This suggests that similar patterns might also occur in more polluted soils. Therefore, species-dependent bioaccumulation patterns could also be used to design phytostabilization and remediation treatments for polluted sites under industrial pressure. [ABSTRACT FROM AUTHOR]

High levels of heavy metal contamination in soil present substantial threats to human health and the environment, leading to severe health problems such as neurotoxicity, cancer, kidney issues, chronic obstructive pulmonary disease, and reduced life expectancy. This research aims to identify and analyze heavy metals in soil samples collected from Superfund sites in North Birmingham, Alabama, specifically in affected areas with zip codes 35207 and 35217 and control area 35214. These affected areas were previously used for mining, coal-fired power plants, coke furnaces, smelting, and other potential sources of heavy metal pollution. Laser-induced breakdown spectroscopy (LIBS) was employed to study 60 soil samples systematically collected from affected and control areas. We found that by using LIBS, we could detect arsenic (As), lead (Pb), and manganese (Mn) in all soil samples from the affected areas. The limit of detection (LoD) was 29.5 mg/kg for Pb, 95.5 mg/kg for As, and 327 mg/kg for Mn using specific parameters of the detection system and/or argon gas purging at atmospheric pressure. The results were compared with ICP-MS measurements to validate the accuracy of the LIBS findings. The data showed good linearity for all calibration data at relatively low concentrations and a good correlation with ICP-MS measurements. [ABSTRACT FROM AUTHOR]

Lake Markakol is located in a metal-rich mountain area of Kazakhstan. Metal input into the lake water and in the bottom sediments can be expected. Lead, cobalt and nickel monitoring in both near-surface and deep-water layers and in bottom sediments was carried out using flame atomic absorption spectrometric analyses. Lead contamination of surface water ranging from 2.6 to 6.8 µg/L occurs in all water samples with the exception of the surface water layer. In the deep-water section concentrations reach up to 13.0–16.2 µg/L. Cobalt concentrations range from 36.8 to 67.5 µg/L in the surface layer and from 25.5 to 69.2 µg/L in the deep-water layer. High values of nickel were found in the surface and bottom layers of the water, ranging from 13.5 to 49.0 and 17.2 to 49.0 µg/L, respectively. High concentrations of lead, cobalt and nickel were identified in all samples of the bottom sediments. The lead content in bottom sediments reaches 11.3, cobalt reaches 10.3–18.0 and nickel reaches 15.0 mg kg−1. The results and their assessment can serve as a basis for future monitoring and measures to reduce pollution, restore the lake ecosystem and ensure the safety of fishery products for humans. [ABSTRACT FROM AUTHOR]

The increasing demand for mineral resources has generated mine tailings with heavy metals (HM) that negatively impact human and ecosystem health. Therefore, it is necessary to implement strategies that promote the immobilization or elimination of HM, like phytoremediation. However, the toxic effect of metals may affect plant establishment, growth, and fitness, reducing phytoremediation efficiency. Therefore, adding organic amendments to mine tailings, such as biochar, can favor the establishment of plants, reducing the bioavailability of HM and its subsequent incorporation into the food chain. Here, we evaluated HM bioaccumulation, biomass, morphological characters, chlorophyll content, and genotoxic damage in the herbaceous Crotalaria pumila to assess its potential for phytostabilization of HM in mine tailings. The study was carried out for 100 days on plants developed under greenhouse conditions under two treatments (tailing substrate and 75% tailing/25% coconut fiber biochar substrate); every 25 days, 12 plants were selected per treatment. C. pumila registered the following bioaccumulation patterns: Pb > Zn > Cu > Cd in root and in leaf tissues. Furthermore, the results showed that individuals that grew on mine tailing substrate bioaccumulated many times more metals (Zn: 2.1, Cu: 1.8, Cd: 5.0, Pb: 3.0) and showed higher genetic damage levels (1.5 times higher) compared to individuals grown on mine tailing substrate with biochar. In contrast, individuals grown on mine tailing substrate with biochar documented higher chlorophyll a and b content (1.1 times more, for both), as well as higher biomass (1.5 times more). Therefore, adding coconut fiber biochar to mine tailing has a positive effect on the establishment and development of C. pumila individuals with the potential to phytoextract and phytostabilize HM from polluted soils. Our results suggest that the binomial hyperaccumulator plant in combination with this particular biochar is an excellent system to phytostabilize soils contaminated with HM. [ABSTRACT FROM AUTHOR]

Kenaf (Hibiscus cannabinu) is a grass bast fiber crop that has the ability to tolerate and accumulate heavy metals, and it has been considered as a potential heavy metal accumulator and remediation plant. Nramp is a natural resistance-related macrophage, which plays an important role in the transport of divalent metal ions, plant growth and development, and abiotic stress. In this study, the Nramp gene family of kenaf was analyzed at the whole genome level. A total of 15 HcNramp genes were identified. They are distributed unevenly on chromosomes. Phylogenetic analysis classified 15 HcNramp proteins into 3 different subfamilies. All proteins share specific motif 4 and motif 6, and the genes belonging to the same subfamily are similar in structure and motif. The promoters are rich in hormone response, meristem expression, and environmental stress response elements. Under different treatments, the expression levels of HcNramp genes vary in different tissues, and most of them are expressed in roots first. These findings can provide a basis for understanding the potential role of the Nramp gene family in kenaf in response to cadmium (Cd) stress, and are of great significance for screening related Cd tolerance genes in kenaf. [ABSTRACT FROM AUTHOR]

Background: Leafy greens, particularly romaine lettuce, are often associated with outbreaks due to their susceptibility to contamination from various environmental sources. This study aimed to evaluate the presence of E. coli, Salmonella, copper, nickel, zinc, and manganese in irrigation water, lettuce leaves, and agricultural soil in the Litani River Basin (LRB), Lebanon. Method: Samples were collected from five demonstration plots employing different agricultural practices. Heavy metal concentrations were determined using atomic absorption spectrometry, while E. coli and Salmonella testing were conducted through conventional culturing techniques. The impact of E. coli contamination on seed germination and the interaction effects between E. coli and heavy metals were also examined. The study also compared the effectiveness of various irrigation systems in reducing bacterial contamination. Results: The results demonstrated that contamination levels varied significantly across the plots and irrigation types. This variation underscores the necessity of site-specific mitigation strategies to enhance food safety. Our findings highlight the importance of selecting appropriate irrigation methods and implementing tailored agricultural practices to minimize the risk of contamination. Conclusion: This research provides valuable insights for optimizing agricultural practices in the LRB to ensure food safety and environmental sustainability. [ABSTRACT FROM AUTHOR]

The bioavailability of heavy metals in soil is a crucial factor in determining their potential uptake by plants and their subsequent entry into the food chain. Various methods, including traditional chemical extractants and the diffusive gradients in thin films (DGT) technique, are employed to assess this bioavailability. The bioavailability of heavy metals, particularly cadmium (Cd) and lead (Pb), is also influenced by soil texture and their concentrations in the soil solution. The primary objectives of this experiment were to compare and correlate the assessment of the Cd and Pb bioavailability using the DGT technique and traditional extractants across two soil textural classes: sandy clay loam (SCL) and clay loam (CL) at two contamination levels: aged contaminated (NC) and artificially contaminated (AC). The specific objectives included assessing the bioavailability of Cd and Pb at different growth stages of the wheat plant and correlating the DGT-based bioassessments of Cd and Pb with their concentrations in various plant parts at different growth stages. This study also compared the effectiveness of the DGT method and traditional extraction techniques in assessing the bioavailable fractions of Cd and Pb in soil. The regression analysis demonstrated strong positive correlations between the DGT method and various extraction methods. The results showed that the wheat plants grown in the AC soils exhibited lower root, shoot, and grain weights compared to those grown in the NC soils, indicating that metal contamination negatively impacts plant performance. The concentrations of Cd and Pb in the wheat tissues varied across different growth stages, with the highest levels observed during the grain filling (S3) and maturity (S4) stages. It is concluded that the in situ assessment of Cd and Pb though DGT was strongly and positively correlated with the Cd and Pb concentration in wheat plant parts at the maturity stage. A correlation and regression analysis of the DGT assessment and traditional extractants showed that the DGT method provides a reliable tool for assessing the bioavailability of Cd and Pb in soils and helped in developing sustainable soil management strategies to ensure the safety of agricultural products for human consumption. [ABSTRACT FROM AUTHOR]

In aquaponic farming, there is a potential risk that heavy metals will contaminate the water, which can lead to heavy metal accumulation in the plants. Our research investigated the accumulation of mercury (Hg) and lead (Pb) under aquaponic conditions and the effect of their increased presence on the uptake of other macro- and micronutrients using watercress (Nasturtium officinale) as a model plant. The potential modifying effect of humic acid on heavy metal accumulation was also investigated. Adding Hg and Pb increased the mercury and lead levels of the watercress plants to over 300 µg kg−1, while the addition of humic acid significantly reduced the concentration of both mercury and lead in the plants compared to plants treated with heavy metals alone, from 310.647 µg kg−1 to 196.320 µg kg−1 for Hg and from 313.962 µg kg−1 to 203.508 µg kg−1 for Pb. For Fe and Mn, higher values were obtained for the Hg + humic acid treatments (188.13 mg kg−1 and 6423.92 µg kg−1, respectively) and for the Pb + humic acid treatments (198.26 mg kg−1 and 6454.31 µg kg−1, respectively). Conversely, the Na, K, Cu levels were lower compared to those in plants treated with heavy metals alone. Our results demonstrated that watercress can accumulate mercury, leading to high levels, even above food safety standards, highlighting the importance of water quality control in aquaponic systems. Furthermore, these results suggest that watercress could be used as a natural filter in recirculation systems. The addition of humic acid significantly reduced the accumulation of heavy metals and altered the element content in the plant. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal that accumulates in plants, negatively affecting their physiological processes, growth, and development, and poses a threat to human health through the food chain. 6-phosphogluconolactonase (PGL) is a key enzyme in the Oxidative Pentose Phosphate Pathway(OPPP) in plant cells, essential for cellular metabolism. The OPPP pathway provides energy and raw materials for organisms and is involved in antioxidant reactions, lipid metabolism, and DNA synthesis. This study describes the Cd responsive gene AetPGL from Aegilops tauschii. Overexpression of AetPGL under Cd stress increased main root length and germination rate in Arabidopsis. Transgenic lines showed higher antioxidant enzyme activities and lower malondialdehyde (MDA) content compared to the wild type. The transgenic Arabidopsis accumulated more Cd in the aboveground part but not in the underground part. Expression levels of AtHMA3, AtNRAMP5, and AtZIP1 in the roots of transgenic plants increased under Cd stress, suggesting AetPGL may enhance Cd transport from root to shoot. Transcriptome analysis revealed enrichment of differentially expressed genes (DEGs) in the plant hormone signal transduction pathway in AetPGL-overexpressing plants. Brassinosteroids (BR), Gibbenellin acid (GA), and Jasmonic acid (JA) contents significantly increased after Cd treatment. These results indicate that AetPGL may enhance Arabidopsis' tolerance to Cd by modulating plant hormone content. In conclusion, AetPGL plays a critical role in improving cadmium tolerance and accumulation and mitigating oxidative stress by regulating plant hormones, providing insights into the molecular mechanisms of plant Cd tolerance. [ABSTRACT FROM AUTHOR]

The impact of trace metal elements (TMEs) on plants is one current pollution problem, the severity of which is increasing with industrial development, population growth and inappropriate agricultural practices. The latter can have irreversible effects on ecosystems, including species extinction, trophic chain contamination and altered human health, particularly in the case of consumed plants such as zucchini squash (Cucurbita pepo L.). This study aims to investigate the effects of nickel on various physiological and biochemical parameters of zucchini growth, with a particular focus on how this toxic metal impacts the quality of fruit that is consumed by humans. To achieve this, plants aged 45 days were grown for one month on solid media loaded with different concentrations of Ni (0, 100, 300 and 500 µM). The results showed that exposure of plants to Ni resulted in significantly altered growth and higher accumulation of Ni in the shoots (1314 µg·g−1 DW) than in roots and fruits. Concerning non-enzymatic antioxidants, the results showed that Ni toxicity significantly increased total polyphenols, especially in shoots at 300 µM Ni, while flavonoid content decreased in the roots and shoots in response to Ni treatment. Our results also show that nickel tolerance in C. pepo is ensured by a combination of several mechanisms such as an increase in the content of proline. This species can survive and tolerate, to different degrees, toxic cations at concentrations up to 500 µM but with visible symptoms of toxicity such as chlorosis of the leaves. Indeed, based on thresholds of hyperaccumulation, we can qualify Cucurbita pepo as a hyperaccumulator species of nickel. [ABSTRACT FROM AUTHOR]

Heavy metal ions such as cadmium, mercury, lead, and arsenic in the soil cannot be degraded naturally and are absorbed by crops, leading to accumulation in agricultural products, which poses a serious threat to human health. Therefore, establishing a rapid and efficient method for detecting heavy metal ions in agricultural products is of great significance to ensuring the health and safety. In this study, a novel optimized spectrometric method was developed for the rapid and specific colorimetric detection of cadmium ions based on N-(2-Acetamido)-iminodiacetic acid (ADA) and Victoria blue B (VBB) as the chromogenic unit. The safety evaluation of ADA showed extremely low biological toxicity in cultured cells and live animals. The standard curve is y = 0.0212x + 0.1723, R2 = 0.9978, and LOD = 0.08 μM (0.018 mg/kg). The liner concentrations detection range of cadmium is 0.1–10 μM. An inexpensive paper strip detection method was developed with a detection limit of 0.2 μM to the naked eye and a detection time of less than 1 min. The method was successfully used to assess the cadmium content of rice, soybean, milk, grape, peach, and cabbage, and the results correlated well with those determined by inductively coupled plasma–mass spectrometry (ICP-MS). Thus, our study demonstrated a novel rapid, safe, and economical method for onsite, real-time detection of cadmium ions in agricultural products. [ABSTRACT FROM AUTHOR]

Climate changes linked to extreme events pose a threat to freshwater biodiversity, impacting organs, behaviour, and reproduction. Moreover, these changes can be amplified by pollution. Copper sulphate (CuSO4) is used in agriculture and aquaculture, so the copper can reach streams, rivers, and lakes impacting fish. This study evaluated the combined effects of temperature and copper on gills and liver histology biomarkers and in the behaviour of Mozambique tilapia over 28 days. Tilapias were exposed to different water temperatures (25 °C and 32 °C) and CuSO4 concentrations (1.1 and 3.6 mg/L). Fish from the control group were exposed to water without copper sulphate and at 25 °C (within their optimum range). Histopathological analysis revealed significant tissue lesions, namely aneurysms and bending of gill lamellae, and hyalinization and vacuolization in the liver at the higher temperature and CuSO4 level. Moreover, behavioural observations revealed increased stress changes under the same conditions. These findings highlight the effects of fast climate change, and rising temperatures on copper toxicity, underlining the necessity for strict monitoring and regulation of copper use due to future climate change scenarios to protect aquatic ecosystems, ichthyofauna population and trophic web dynamics. This data also alerts for similar problems with other toxic metals or chemicals, at short term, in streams and rivers, under rapid climate changes and more frequent extreme events. [ABSTRACT FROM AUTHOR]

Monitoring and protecting flowing watercourses is a complex and challenging task that requires the collaboration and coordination of various stakeholders such as governments, industries, farmers, consumers and environmental groups. The study of the dynamics of the concentration of polluting factors and especially the concentrations of heavy metals and highlighting a seasonal variation is a necessary element from this point of view. In this article, we present the results of our analyses carried out in two measurement campaigns executed in 10 monitoring points along the Danube River, between Braila city and Isaccea city in the pre-deltaic area, during the summer season and autumn season 2022. The importance of this area is given by the fact that the Danube Delta is part of the UNESCO heritage, and the monitoring of polluting factors is a necessity in the desire to protect this area. The data measured during the July and August 2022 campaign cover a wide range of chemical species: Phosphate, CCO, CBO5, NH4+, N-NO2, N-NO3−, N-Total, P-PO4 3−, SO42−, Cl−, phenols, as well as metals with a harmful effect: Al, As, Cd, Cr, Fe. The study includes an evaluation based on the statistical approach of the results to highlight the significant correlations and differences identified between the two data sets. Next, to highlight the obtained results, a numerical model was considered using HEC-RAS and ESRI ArcGIS applications in a two-dimensional unsteady flow model in order to obtain the non-homogenous concentrations' distributions in the studied area. These two-dimensional models have been less studied in the specialized literature. In this way, interesting results could be obtained, and prediction methods regarding the dynamics of metal concentrations could be structured. The data obtained were used for the terrain model from the USGS service, and the flows of the Danube and its two tributaries were simulated using the data provided by the national services. In this work, we present the results obtained for the dynamics of the concentrations of the metals Al, As, Cd, Cr and Fe and the evaluation of the specific absorption coefficients for the explanation and correlation with the results of the measurements. Except for the numerical model presented, we would like to highlight the existence of some contributions of the main tributaries of the Danube in the study area. Such a systematic study has not been carried out due to conditions imposed by the border authorities. From this point of view, this study has an element of originality. The study is part of a more complex project in which the spatio-temporal distribution of the polluting factors in the water was evaluated, and the habitats in the study area were inventoried—especially those of community interest. In this way, we were able to expose the self-purification capacity of the Danube and highlight the existence of a concentration reduction gradient along the course of the river. The aspects related to the influence of the distribution of polluting factors on the state of health will be the subject of another article. [ABSTRACT FROM AUTHOR]

In the face of current challenges related to climate change, maintaining the appropriate quality of freshwater becomes crucial. This study examined the effectiveness of removing heavy metals (Cu(II) and Co(II)) using Chlorella vulgaris biosorbents (dietary supplements in the form of powder). This study determined the parameters of the biosorbent (point of zero charge (PZC) analysis using scanning electron microscopy with back-scattered electron (SEM-BSE) and Fourier transform infrared spectroscopy (FT-IR) analysis). Batch tests were also performed to determine the kinetic constants and adsorption equilibrium of Cu(II) and Co(II) ions. Based on the conducted research, it was found that a pseudo-second-order equation describes the kinetics of the biosorption process. Among the studied adsorption isotherms, the Langmuir and Freundlich models fit best. The results indicate that single-layer adsorption took place and Chlorella vulgaris is a microporous adsorbent. The maximum sorption capacity in the single-component system for Cu(II) and Co(II) was 30.3 mg·g−1 and 9.0 mg·g−1, respectively. In contrast, in the binary system, it was 20.8 mg·g−1 and 19.6 mg·g−1 (extended Langmuir model) and 23.5 mg·g−1 and 19.6 mg·g−1 (Jain-Snoeyinka model). Chlorella vulgaris is an effective biosorbent for removing heavy metals from freshwater. This technology offers an ecological and economical solution for improving water quality, making it a promising alternative to traditional purification methods. [ABSTRACT FROM AUTHOR]

This study investigates the removal of heavy metals, particularly copper and nickel, from acidic aqueous solutions using the weakly base polymeric chelating resin Dowex M-4195. The research conducts comprehensive cost–benefit and statistical analyses of various kinetic and isotherm adsorption models. The results show that the PSO and general order models provide high accuracy for the Cu2⁺ adsorption kinetics, while the Avrami fractional order model excels for Ni2⁺. In terms of the isotherm models, the Langmuir and Jovanovic models are highly accurate for both metals, with the Toth model being particularly effective for Ni2⁺ due to its ability to account for surface heterogeneity and multi-layer adsorption. This study also reveals that the kinetic adsorption process is more economically beneficial than the isotherm adsorption process, highlighting the importance of model selection for optimizing heavy metal removal. Incorporating circular economy principles, this research emphasizes the sustainability of using regenerable and reusable adsorbents like Dowex M-4195. The findings provide valuable insights for designing efficient adsorption systems, promoting environmental sustainability, and ensuring public health safety. [ABSTRACT FROM AUTHOR]

Microbial remediation has become a prominent focus in soil pollution control due to its environmental friendliness, cost-effectiveness, and high efficiency. The effectiveness of microbial remediation is rooted in the interactions between microbial metabolic activities and the soil environment. Various microorganisms employ distinct mechanisms for pollutant treatment, including surface adsorption, intracellular accumulation, and biomineralization. Using the Web of Science Core Collection database, tools such as CiteSpace 6.1.R6, VOSviewer 1.6.20, and HistCite Pro were employed to conduct a quantitative analysis of several key aspects: the volume and thematic distribution of research papers on microbial remediation of soils, the cooperative networks between countries and institutions, the leading journals, major research hotspots, and emerging trends. The analysis reveals that utilizing microbial regulatory mechanisms and functions to remediate inorganic pollutants, such as heavy metals, and organic pollutants, such as PAHs, is becoming a significant frontier in future research. This study provides a valuable reference for scholars aiming to understand the current status of microbial research in soil remediation, both domestically and internationally. It also offers guidance for developing efficient, sustainable, and safe remediation strategies while identifying directions for future innovative research. The specific results are as follows: (1) China, the USA, India, and other countries have a high frequency of citations in this field, and the research is more in-depth. (2) More and more attention has been paid to the use of microbial remediation of contaminated soil in the world, mainly in Environmental Sciences. (3) Major publications include Chemosphere, Journal of Hazardous Materials, and Science of The Total Environment. In the key literature, the use of microorganisms to restore the soil environment and the combination of microorganisms and plants to repair soil contaminated by heavy metals occupy a high proportion. (4) The key areas of focus include the application of microorganisms in soil inorganic pollution remediation, the application of microorganisms in remediation of soil organic pollution (crude oil and polycyclic aromatic hydrocarbons (PAHs)), and the contribution of microorganisms to soil pollutant degradation and toxicity assessment systems. The research and development of combined microbial remediation technology is the current research hotspot in the field of soil remediation, focusing on the symbiosis between mycorrhizal fungi and plant roots, the enhancement in the ability of microorganisms to absorb and degrade pollutants and their tolerance, and the interaction mechanism between indigenous microorganisms and plants. [ABSTRACT FROM AUTHOR]

To seek a restoration plan for the safe use of agricultural land around mining areas, this study focuses on the regions around a mining plant in Huidong County, western Sichuan Province, affected by lead–zinc mining, and the precise remediation of heavy metal pollution through large-scale synthesis of iron silicate. In this study, we investigated heavy metal pollution in the vicinity of the mining area and proposed a treatment strategy using large-scale synthesis of iron silicate to mitigate this pollution. According to field investigation and sampling analysis, the collected soil samples contained excessive Cd, Pb, and Zn. Cd is a heavy metal related to lead–zinc mining. The planting of crops such as loquats and garlic with a high accumulation coefficient for Cd was found inappropriate for the research area. Instead, it was recommended to plant economically important crops like mangoes and peaches which had lower heavy metal accumulation. On the basis of field investigation, the study area was seriously polluted by heavy metals, among which Cd was 4.0 times higher than the standard of agricultural land. In order to accurately passivate excessive Cd, Zn, and Pb, iron silicate material was put into mass production. In situ passivation experiments showed that when the soil water content was between 25% and 20%, adding 4% silicate material could rapidly reduce the content of effective heavy metals in the soil and the heavy metal content of garlic and other cash crops in the research area by about 8%. After conducting a field investigation, it has been determined that the large-scale preparation of iron silicate can accurately repair soil contaminated by heavy metals in the vicinity of mining areas. In conclusion, iron silicate is capable of effectively reducing the pollution of heavy metals on agricultural land and facilitating the safe utilization of such land. [ABSTRACT FROM AUTHOR]

Heavy metal contamination is an alarming concern on a global scale, as drinking tainted water significantly increases human susceptibility to heavy metals. In a realistic scenario, humans are often exposed to a combination of harmful chemicals rather than a single toxicant. Phloretin (PHL), biochanin‐A (BCA), and coenzyme Q10 (CoQ10) are bioactive compounds owning plentiful pharmacological properties. Henceforth, the current research explored the putative energizing effects of selected nutraceuticals in combined chromium (Cr) and arsenic (As) intoxicated Swiss albino mice. Potassium dichromate (75 ppm) and sodium meta‐arsenite (100 ppm) were given in the drinking water to induce hepatotoxicity, conjugated with PHL and BCA (50 mg/kg each), and CoQ10 (10 mg/kg) intraperitoneally for 2 weeks. After the statistical evaluation, it was observed that the hepato‐somatic index, metal load, and antioxidant activity (lipid peroxidation and protein carbonyl content) increased along with the concomitant decrease in the antioxidants (catalase, glutathione‐S‐transferase, superoxide dismutase, reduced glutathione, and total thiol) in the Cr and As intoxicated mice. Additionally, light microscopy observations, DNA breakages, decreased silent information regulator 1 (SIRT1), nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2), heme oxygenase (HO‐1), and NAD(P)H quinone dehydrogenase 1 (NQO1) gene expressions, together with stimulated apoptotic cell death manifested by the increased expressions of caspase 8 and caspase 3, thus, proved consistency with the aforementioned outcomes. Importantly, the treatment with nutraceuticals not only restored the antioxidant activity but also favorably altered the expressions of SIRT1, Nrf2, HO‐1, and NQO1 signaling and apoptosis markers. These findings highlight the crucial role of the PHL, BCA, and CoQ10 combination in reducing Cr and As‐induced hepatotoxicity in mice. By averting the triggered apoptosis in conjunction with oxidative stress, this combination increases the SIRT1, Nrf2, HO‐1, and NQO1 signaling, thereby reassuringly maintaining the cellular equilibrium. Highlights: Chromium and arsenic are the two major heavy metals that pose a significant threat to living beings by altering the biochemical equilibrium.Exposure to combined Cr + As for 2 weeks led to the generation of free radicals resulting in the damage of liver tissue.Treatment with natural bioactive compounds (PHL, BCA, and CoQ10) impeded the Cr + As‐induced hepatic toxicity by scavenging the free radicals and reducing the triggered oxidative stress together with preventing the dysfunctioning of SIRT1/Nrf2/HO‐1/NQO1 and caspase cascade. [ABSTRACT FROM AUTHOR]

In today's society, with the continuous development of manufacturing industries and factories related to chemicals, the amount of heavy metals in the inhaled air of humans, water and even food consumption has increased dramatically. The aim of this study was investigation of relationship between exposure to heavy metals on the increased carcinogenicity risk of kidney and bladder. Databases used to for searched were the Springer, Google Scholar, Web of Science, Science Direct (Scopus) and PubMed. At the end after sieve we selected 20 papers. Identify all relevant studies published 2000–2021. The results of this study showed that exposure to heavy metals due to the bio accumulative properties of these metals can cause kidney and bladder abnormalities and provide the basis through various mechanisms for malignant tumors in these organs. Based on result this study, since a limited number of heavy metals including copper, iron, zinc and nickel in very small amounts as micronutrients play a very important role in the function of enzymes and the body cells biological reactions, but exposure to some of them like arsenic, lead, vanadium and mercury will cause irreversible effects on people's health and cause various diseases including cancers of the liver, pancreas, prostate, breast, kidney and bladder. The kidneys, ureter and bladder are the most important organs in the urinary tract on human. According to the result of this study, the duty of this urinary system is to remove toxins, chemicals and heavy metals from the blood, balance electrolytes, excrete excess fluid, produce urine and transfer it to the bladder. This mechanism causes the kidneys and bladder to be highly associated with these toxins and heavy metals, which can lead to various diseases in these two important organs. According to the finding the reducing exposure to heavy metals in various ways can prevent many diseases related to this system and reduce the incidence of kidney and bladder cancers. [ABSTRACT FROM AUTHOR]

Production of green energy from landfill gas in a cogeneration system is considered optimal in terms of the use of local renewable energy resources, which in the production process generates hazardous waste. Yet, the production of renewable energy is not without environmental effects. The objective of the work was to analyse the operation of the installation for biogas energy generated at a municipal waste landfill and to carry out tests on the waste (mineral deposit) from a heat exchanger generated in the exhaust manifold of a gas engine of the cogeneration unit. The objective of the work was to test waste (mineral deposit) from the heat exchanger in the exhaust manifold of the gas engine of the cogeneration unit. The conducted research constitutes a significant contribution to the identification and classification of hazardous waste generated in a cogeneration unit powered by landfill gas. The results of the research showed that the waste contains high concentrations of ecotoxic elements, i.e. heavy metals (arsenic, chromium, copper, nickel, zinc), molybdenum, antimony, sulphates, which have carcinogenic activity. Pioneering research performed as part of the leaching test showed that the permissible concentrations were exceeded for 11 parameters in the case of storage in a hazardous waste landfill, and for 6 parameters in the case of storage in an underground hazardous waste landfill. The research and analyses performed in this work will serve as input material for defining the methods of hazardous waste disposal from the cogeneration unit. [ABSTRACT FROM AUTHOR]

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The build-up of arsenic in agricultural soil through contaminated irrigational groundwater is a concern. Metagenomic analysis of such contaminated sites may provide a remarkable opportunity to extensively investigate the responses and adaptation of microbial communities to different levels of arsenic. The study focuses on the comparative analysis of microbial community composition and associated functions in paddy soil samples with a gradient of arsenic contamination (4.88 to 43.67 mg kg−1). Actinobacteria was found to dominate the bacterial phyla in all four samples with abundance ranging from 39.77% to 49.39% followed by Proteobacteria (20.71–38.24%). Whereas the fungal phylum Ascomycota (92.42–95.29%) dominated all the samples studied. In the study, bacteria were found to be abundant in the mid-level (15.89 and 24.84 mg kg−1) of arsenic, which included genera Gaiella, Nocardioides, Solirubrobacter, Microvirga, and Nitrospira. Fungi Beauveria, Talaromyces, Aspergillus, Pyrenophora, and Valsa were higher in relative abundance corresponding to soil arsenic concentration. Verticillium, previously reported for Pb, Zn, and Cd removal, was found in the soil sample with the mid-arsenic concentration (15.89 mg kg−1). The relative abundance of the arsenic metabolizing/ transport genes of native microbial communities also varied with the soil arsenic gradient, the genes arsJ, arsM, aioR, arsH, and arsC being the most affected. The study is the first report of Gaiella, Solirubrobacter, Beauveria, and Verticillium present in arsenic-contaminated soil, and further studies are required to explore their potential role in arsenic bioremediation. [ABSTRACT FROM AUTHOR]

Heavy metal pollution is a silent killer and has become a pervasive issue in various regions worldwide, particularly within developing nations such as Nigeria. This study undertook a thorough examination of 120 scholarly articles published from 2000 to 2019, aimed at evaluating the prevalence of heavy metal pollution in soils, aquatic environments, and food sources including crops, meat, and dairy products. Methodologies employed for sample collection and metal quantification were critically assessed, alongside an extensive discussion on the concentrations, sources, and levels of contamination observed. The investigation revealed elevated concentrations of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), cobalt (Co), chromium (Cr), iron (Fe), and arsenic (As) across all examined locales, with average metal concentrations surpassing World Health Organization/Food and Agriculture Organization (WHO/FAO) guidelines for soil. Furthermore, higher metal concentrations were detected in surface and well waters, whereas borehole groundwaters were relatively pollution-free. Analysis of food crops, meat, and milk demonstrated metal concentrations exceeding WHO/FAO standards across all urban areas studied. Contrary to expectations of lithogenic toxicity, the primary sources of contamination were identified as anthropogenic, stemming from dumpsites, landfill sites, mining operations, runoff and seepage from automotive repair workshops, petroleum hydrocarbon spills, and effluents from industrial plants. The geo-accumulation index (Igeo) analysis revealed significant soil contamination with Fe and Cd, classified under extremely serious and moderate contamination levels, respectively. This comprehensive review highlights the necessity for viable and clear policy interventions to mitigate heavy metal pollution and advocates for the rigorous monitoring and control of industrial activities. [ABSTRACT FROM AUTHOR]

In this paper, the Chinese Taoist medicinal herb Codonopsis and its rhizosphere soils from Pingshun County, Shanxi Province, were used as the research objects. Using GIS, descriptive statistics, The BP neural network model constructed by Python, we studied the potential factors to control the enrichment and migration of heavy metal elements in the soil-Codonopsis system under different sources. It was found that the heavy metal elements in the soils of the region were mainly divided into natural background and source of mineral veins, and the content of heavy metal elements in Codonopsis and rhizosphere soils under vein sources was found to be higher than the natural background, while there was no significant change in the corresponding rhizosphere soils, and the biological effectiveness of heavy metal elements in Codonopsis under vein sources was significantly increased, among which Cu, Cd were even more enriched. The bioeffectiveness of heavy metal elements in Codonopsis from mineral veins was significantly increased, among which cu and cd were superenriched. The migration of most heavy metal elements in the natural background was mainly influenced by soil pH, while in the case of mineral vein contamination, the key factors controlling the migration of heavy metal elements were mainly inter-element interactions. Therefore, the subsequent planting of Codonopsis should be far away from the area of vein development and focus on the effect of pH on its quality. [ABSTRACT FROM AUTHOR]

Lake Tanganyika, the second deepest lake in Africa, has a unique ecosystem that provides rich fish proteins for populations along the lake basin. With socioeconomic development and rapid population growth, Lake Tanganyika is threatened by environmental pollution. In this study, the concentrations of heavy metals, including Cr, Ni, Cu, Zn, Cd, Pb, Fe, and Mn, in the surface sediments of the inflow rivers in northeastern quadrant of Lake Tanganyika were characterized. The geoaccumulation index (Igeo) and enrichment factor (EF) were employed for heavy metal assessment. The results showed that heavy metal concentrations in the surface sediments of the inflow rivers in northeastern quadrant of Lake Tanganyika exhibited significant spatial variations. The concentration of heavy metals was the highest near urban areas, followed by the estuarine wetland and forest grassland. This indicated that heavy metal content was closely related to human activities. The concentrations of Zn, Cd, and Pb were defined as unpolluted, and the concentrations of Pb, and Fe were only slightly enriched. Principal component analysis and cluster analysis demonstrated that the heavy metals Cr, Zn, Cd, and Pb may originate from a mixture of natural sources and anthropogenic inputs, including agricultural and industrial inputs. Ni, Fe, and Mn were principally from natural sources, and Cu primarily originated from anthropogenic inputs such as vanadium iron ore mining and iron and steel smelting. These results are important for understanding the nonpoint sources of heavy metal pollution in the Lake Tanganyika Basin. [ABSTRACT FROM AUTHOR]

Heavy metals are one of the major toxic pollutants affecting water quality. The higher concentrations of heavy metals in the environment cause water quality deterioration. As these metals are used for various purposes, they enter in the effluent streams of these processes. Their removal and recovery without further contamination would enhance their recyclability and usability in further applications. The use of graphite nanoplatelets (GNPs) with a polysulfone (PSF) based membrane is one potential solution to this issue. This will lead to rejection of heavy metals through the Donnan Exclusion Principle. At the same time, it offers the chemical and mechanical stability of PSF, and GNPs can be chemically modified to provide desired charge to membrane surface for optimum removal of heavy metals. Experiments using ultrafiltration membranes with GNPs anchored on them showed an increase in pore density, hydrophilicity, water flux and permeability transport properties. In addition, experiments involving Mn and Cr rejections revealed 96.97 and 93.07% rejections when 0.2% wt of GNP was included in the PSF based membrane. This highlights the importance of GNP treatment with suitable materials providing lower pore size and increased porosity and rejection of Mn and Cr. Such higher porosity would help to enhance transport rate and rejection properties which is necessity for successful industrial applications. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) and microplastics (MPs) are toxic environmental pollutants that severely risk ecosystems and living organisms. The interactions of these pollutants in the aquatic environment can impact their bioavailability, toxicity, and bioaccumulation potential in organisms. Various factors, including temperature, pH, salinity, polymer type, particle size and microbial abundance, influence these interactions and are likely to increase their influence on aquatic biota and human beings. MPs have been recognized as heavy metal transporters in aquatic environments that exhibit various harmful effects. However, MP interactions with heavy metals are poorly understood. Hence, it is important to understand the detailed mechanism, mainly absorption vs ingestion, MPs degradation with metal fate and combined effects on living organisms. To tackle and reduce the harmful effects on biodiversity, it is essential to comprehend the underlying mechanisms (e.g. adsorption, desorption, bio-uptake, and synergistic effects). Also, more research is required to comprehend the intricate connections between MPs and HMs in an array of environmental situations, which could lead to innovative solutions for mitigating their detrimental environmental consequences. This review paper discusses microplastic's prevalence, concentration, adsorption, and dissociation characteristics concerning HMs in aquatic ecosystems that must be understood to reduce their deleterious effects on aquatic biodiversity. Understanding these complex interactions between MPs and HMs is critical to assessing the ecotoxic effects and preventing environmental pollution. This review paper also underscores the nature of environmental pollutants, including the interaction mechanisms of MPs and HMs, emphasizing the importance of multifaceted approaches that need to be adapted to mitigate their combined effects. [ABSTRACT FROM AUTHOR]

Airborne particulate pollution, which contains heavy metals (HMs) among other contaminants, is associated with many health effects related to respiratory problems, such as cardiopulmonary lesions and systemic diffusion. This study aimed to evaluate the levels of HMs contamination using different plants and monitors, as well as to evaluate the relationship between HMs content and magnetic properties in leaves of different types of biomonitors. For analysis, 180 samples were taken from biomonitors; Cupressus lusitanica (Cupressaceae), Citrus (Rutaceae), and Ficus benjamina (Moraceae), and monitors (road dust, surface and, deep soil). Seven HMs were measured: Cu, Pb, Ni, Cr, Fe, V, and Zn in all samples. Specific susceptibility (χlf), and isothermal remanent magnetization curves (IRM) were assessed in biomonitors samples. The results revealed that the major biomonitor was C. lusitanica, which also showed the highest χlf (20.54 × 10–8 m3/kg) and IRM (2.66 mAm2/kg). Additionally, given the low coercivity of the magnetic material found in the χlf and SIRM values, those magnetic properties can be used interchangeably to determine the magnetic minerals in the biomonitors studied. We conclude that the use of biomonitors and monitors presents a potential to be used as an alternative method for contaminant monitoring and the use of magnetic properties is feasible to measure air pollution. [ABSTRACT FROM AUTHOR]

The utilization of treated wastewater (TWW) for agricultural irrigation can enhance soil properties and fertility for better crop growth. However, toxic chemicals in TWW, if exceeding permissible limits, pose environmental and health risks. This study aims to evaluate the quality of treated wastewater (TWW) and groundwater used for irrigation in alfalfa and date palm fields, focusing on specific ion toxicity, salinity, heavy metal concentrations, and other water quality parameters. Water samples were collected from four plantation sites in the Ibra and Alqabil provinces during the summer and winter seasons of 2020 and 2021. The samples were analyzed for electrical conductivity (EC), pH, total dissolved solids (TDS), carbonate, bicarbonate, and the presence of arsenic (As), cadmium (Cd), cobalt (Co), boron (B), lead (Pb), nickel (Ni), copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and chromium (Cr). The findings reveal that both TWW and groundwater in the sampled sites exhibited salinity levels detrimental to sensitive crops. Trace element concentrations generally adhered to permissible limits as defined by FAO and Oman standards, except for boron, which exceeded allowable limits by up to 40% in groundwater when compared to the control site. Notably, cobalt (Co), arsenic (As), and cadmium (Cd) were undetectable in all water samples. Additionally, groundwater samples taken in close proximity to sewage treatment plants (STPs) displayed a 37% increase in EC, TDS, and heavy metal concentrations. This suggests that groundwater, like TWW, may contain undesirable salts and heavy metals that could compromise water quality. This research underscores the importance of monitoring and assessing the quality of both treated wastewater and groundwater used for irrigation. While these water sources hold potential benefits for agriculture, they also carry the risk of negatively impacting soil and crop health due to salinity and the presence of certain contaminants. This study provides critical insights into the safe use of TWW and groundwater in agricultural practices, highlighting areas for improvement in water treatment and management strategies to ensure sustainable agricultural productivity. [ABSTRACT FROM AUTHOR]

This study quantified the concentrations of trace and heavy elements, including Al, K, Ca, Mg, Zr, Ti, La, Ce, Mn, Cr, Zn, and Nd, in soil samples from Tukwikwi. It also assesses the potential human health risks posed by exposure to these metals through ingestion, inhalation, and dermal absorption for both children and adults. The study area lies in Hadejia flood plain between latitudes 12°10′ N to 13°0′ N and longitudes 10°15′ E to 11°30′ E. The result showed that the mean concentrations of Al (47,140 mg/kg), K (23,110 mg/kg), Fe (18,020 mg/kg), Mg (7810 mg/kg), Zr (404 mg/kg), and La (64 mg/kg) exceeded the crustal values of Al (25,000 mg/kg), K (10,700 mg/kg), Fe (9800 mg/kg), Mg (7000 mg/kg), Zr (220 mg/kg), and La (30 mg/kg). By contrast, the concentrations of Ca, Cr, Ce, Mn, Ti, Zn, and Nd were lower than the crustal values. These crustal values were used, as there were no regional values that could be used for comparison. The result of the noncarcinogenic health risk assessment showed that Al exhibited the highest value ranging from 5.52×10−1$5.52 \times {{10}^{ - 1}}$ to 7.51×10−1$7.51 \times {{10}^{ - 1}}$ for children and 7.3×10−1$7.3 \times {{10}^{ - 1}}$ to 9.9×10−1$9.9 \times {{10}^{ - 1}}$ for adults. The results also revealed that adults have a higher potential risk than children. The results for the carcinogenic risk (CR) showed that the total CR (TCR) values for Cr ranged from 0 to 3.20×10−4$3.20 \times {{10}^{ - 4}}$ for children and 0 to 4.29×10−4$4.29 \times {{10}^{ - 4}}$ for adults, which are higher than the acceptable limit of 1×10−4$1 \times {{10}^{ - 4}}$. These suggest that there are health concerns for adults and children in the research area. This necessitates the need for monitoring the soil in the study area to reduce potential environmental issues. [ABSTRACT FROM AUTHOR]

An extensive concentration of heavy metals in our environment creates a harmful impact on living organisms, including microorganisms. Regardless of exploring the remediation potential of bacteria, their corresponding changes have not been extensively examined, which might be crucial before promoting bioremediation technology. The present study aimed to determine the effects of both essential (Cu) and nonessential (Pb) heavy metals on the bioactivity of a ubiquitous bacterium Bacillus sp., to gain knowledge about the adaptive mechanisms the strain has developed to withstand exposure to these metals. Bacterial adaptation is related to the formation of biofilm and the production of exopolysaccharides (EPSs) along with other tactics that assist in the survival of bacteria. When Bacillus sp. was cultured with Cu and Pb, changes in its bioactive characteristics were observed, such as a significant reduction in biofilm formation by 30.13% compared to the initial value. Moreover, the output of EPS by the bacterial strain in the presence of Pb increased to 0.782 mg/mL compared to the control condition, where no EPS was formed. In the presence of Cu, a low concentration of EPS (0.103 mg/mL) was detected. Moreover, the bacterial strain demonstrated adapted resistance to 6 out of 11 tested antibiotics, where the strain transformed from intermediate sensitivity to being susceptible to doxycycline, chloramphenicol, and gentamycin. Finally, the Cu‐ and Pb‐degrading capacity of the bacterium was scrutinized using a flame atomic absorption spectrophotometer, where the bacterium exhibited significant degradation rates, breaking down 14.49% of Cu and 37.30% of Pb within 7 days. This research revealed the adaptability of the bacterial strain to survive in the presence of Cu and Pb while degrading them, by changing its bioactive properties, through the downregulation of biofilm formation, the productivity of EPS, and the heavy metal degradation process. [ABSTRACT FROM AUTHOR]

The study evaluated the water quality index (WQI) and heavy metal pollution index (HPI) of different industrial effluent and surface water from various sites of the Karnaphuli River, based on the weighted arithmetic index method. The samples were collected from 20 different industries, including textile dyeing, textile washing, oil processing, chemicals, and tannery, and 17 stations of the Karnaphuli River, from the Kalurghat Bridge to the estuary where the river meets with the Bay of Bengal. This study was carried out in the dry season of the 2021–2022 fiscal year. Six physicochemical parameters, namely pH, biochemical oxygen demand, chemical oxygen demand, total dissolved solids, electrical conductivity, and hardness, were taken for the determination of the WQI, and concentration of heavy metals (Pb, Fe, Cd, Cu, Cr, Mn, and Ni) were considered for the calculation of the HPI. Both indexes were calculated against the Bangladesh Standard (denoted by subscript a) and WHO standards (denoted by subscript b). The water quality indexes WQIa and WQIb for industrial effluent ranged from 11.66 to 176.77 and 44.45 to 9703.99, respectively. Samples namely TD‐5, TD‐7, TD‐8, TD‐9, TD‐10, OS‐1, and C‐1 showed excessively high WQI value. On the other hand, the HPIa and HPIb of industrial effluent varied from 43.6 to 167,785.3 and 0.34 to 18,412.3, respectively. Furthermore, oil processing and chemical effluents showed noticeably higher HPI values than other industrial samples. Both WQI and HPI values indicated a serious pollution load in most experimental samples. No river water sample showed a WQI value below 100, denoting it was unfit for consumption. The water quality indexes WQIa and WQIb for river water samples ranged from 1275.40 to 29,405.77 and 131.20 to 5860.99, respectively. According to the Bangladesh Standard, the river water samples were moderately to highly polluted by metal. The highest HPI value for the river water sample was 7965, denoting extreme metal pollution. The investigation revealed that most industrial effluents and Karnaphuli River water samples contained significant pollution load. Therefore, effective measures must be adopted immediately for future sustainability to cope with this contamination. The results emphasize the immediate requirement for strict regulations and advanced water treatment technologies to reduce contamination risks in the Karnaphuli River. Prompt action by authorities is essential to safeguard the river, prevent ongoing ecological damage, and address metal accumulation in fish affecting the food chain. Public awareness and legislative measures are vital for ecosystem preservation. [ABSTRACT FROM AUTHOR]

The study is aimed at assessing the impact of biochar on the phytoaccumulation of heavy metals by okra and fluted pumpkin plants in soil polluted with petroleum hydrocarbons, and its corresponding environmental and health‐related risks. A field experiment was conducted at the automobile workshop (commonly called mechanic village) using a randomized complete block design (RCBD). The field was divided into plots and three replicates. Maize stalk biochar (MSB) and nipa palm biochar (NPB) were treated differently in each plot at a rate of 20 t ha−1. Plots containing no biochar were used as controls. The soil samples were analyzed for petroleum hydrocarbon content (PHCt), selected heavy metals as well as some other soil physicochemical properties. Plant samples were only analyzed for heavy metal contents. Analysis of variance was used to analyze the data generated. The PHCt and heavy metal content in the soil were compared with the target values set by the Department of Petroleum Resources of Nigeria whereas heavy metals in plants were compared with FAO/WHO guidelines. Okra and fluted pumpkin were evaluated for phytoaccumulating potential using bioaccumulation factor (BAF). Ecological risk assessment was done using a hazard quotient (HQ). The PHCt, cadmium (Cd), chromium (Cr), and nickel (Ni) were significantly decreased following the application of biochar. The NPB recorded the lowest values for PHCt (64.4 mg kg−1), lead (16.0 mg kg−1), and Ni (12.8 mg kg−1) contents while MSB had the lowest values for Cd (0.3 mg kg−1) and Cr (7.6 mg kg−1) contents. The HQ analysis showed that Cr (2.93 mg kg−1) and Pb (156.83 mg kg−1) posed a very high ecological risk to the local ecosystem. The phytoaccumulated heavy metals in plants were above the maximum allowable levels, except Ni where the content was below the maximum allowable levels. Fluted pumpkin had the highest BAF values for Cd, Cr, Pb, and Ni. Therefore, fluted pumpkin can be used as an efficient phytoremediator for soil contaminated with Cd, Cr, Pb, and Ni. [ABSTRACT FROM AUTHOR]

The global concern over health issues related to heavy metal pollution has driven the adoption of various treatment technologies. The investigation into optimal conditions for cadmium biosorption and bioaccumulation was conducted using a resilient bacterial strain, Pseudomonas aeruginosa DR7, which was isolated from ponds. The equilibrium time of the adsorption process of living cells was much longer than that of non‐living cells, which was about 240 min, which indicates that living cells have intracellular accumulation and delay the adsorption process. Living cells favored a pH of 6.0, while non‐living cells showed higher efficiency at pH 7.0, demonstrating the pH‐dependent nature of metal biosorption. In this context, the maximum biosorption capacities for cadmium using non‐living cells and living cells were 103.8 mg/g and 70.94 mg/g, under cell mass of 1.0 g/L, pH 7.0, initial metal concentration of 200 mg/L, and contact time of 240 min, respectively. Cadmium biosorption by living cells was more accurately described by the Freundlich isothermal model, whereas the Langmuir model was used for non‐living cells. Living cells tend to show pseudo‐second‐order kinetic adsorption behavior, while non‐living cells tend to show pseudo‐first‐order kinetic adsorption behavior. Fourier‐transform infrared spectroscopy (FTIR) analysis suggested that the hydroxyl, amino, and carboxyl groups all play a role in biosorption. Scanning electron microscopy (SEM)–energy dispersive x‐ray spectroscopy (EDS) showed that the high‐temperature treatment destroys the integrity of the cell wall, which enhances the permeability of the cell wall, thus increasing the biosorption of Cd (II) by the non‐living cells. The study found that P. aeruginosa DR7 with high temperature inactivation has a higher Cd(II) adsorption capacity than living cells, making it a green and environmentally friendly biological adsorbent for wastewater treatment with heavy metals. [ABSTRACT FROM AUTHOR]

Pyrolysis is a promising alternative for the removal or immobilization of hazardous elements in sewage sludge (SS) without compromising its biofertilizer features. However, the effects of pyrolysis on SS emerging contaminants have not been fully investigated. Therefore, this study aimed to assess the fate of heavy metals, pesticides, and organic pollutants in SS through pyrolysis, as well as the suitability of SS and its derived biochar (SSB) for soil application. Municipal SS was pyrolyzed at different scales (bench and micro units) and temperatures (400, 500, and 600°C) for comparison. The general properties, surface morphology, and functional groups of SS and SSB were analyzed. Also, a quantitative analysis of heavy metals (Zn, Cu, Cr, Ni, Cd, and Pb) and a qualitative investigation of organic pollutants and pesticides were performed. The results demonstrated that pyrolysis at 400°C increased the stability of SS and strongly affected its surface area, resulting in a high pore structure with a developed surface charge. Simultaneously, the relative content of organic matter and nutrients remained nearly unchanged. All heavy metals analyzed in SS and SSB400 were within limits set by the International Biochar Initiative for soil application. Moreover, organic pollutants and pesticides were detected in the SS but were partially degraded or immobilized after pyrolysis > 400°C. In conclusion, the production of SSB proved to be an effective method for removing toxic elements from SS while enhancing its properties for soil remediation and crop productivity. [ABSTRACT FROM AUTHOR]

A detailed assessment of heavy metal concentration has been done through a regional geochemical survey near an industrial area in the outskirts of Raipur City. The multi‐metal analysis was carried out through detailed sampling of stream sediments and slope wash samples. All heavy metals like Cobalt (Co), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), and Arsenic (As) are found to present at higher concentrations than their permissible limits. The maximum concentration of heavy metals in descending order of occurrences for Cr, Pb, Cu, Co, Ni, and As were 213, 68, 55, 54, 45, and 35, ppm, respectively. The weathering of the carbonate rocks present in the area is found to be the source of a few metals like Ni, Cr, and Cu. Other metals like Co, Pb, and As are observed at higher concentrations near the industrial areas in the northwestern part. The chemical effluents released from the steel industries are believed to be the prime source of these metals, which also confirmed through field validation. This study emphasizes the significance of the geochemical database generated by National Geochemical Mapping (NGCM) for social and environmental goals. [ABSTRACT FROM AUTHOR]

The study assessed the quality of water obtained from River Ogio in Etsako West Local Government Area of Edo State, Nigeria. Using standard procedures, the water samples obtained from three points of the river were analyzed for physicochemical parameters, Total heterotrophic bacteria count and Total coliform count. With exception of upstream samples, the temperature of midstream and downstream samples was lower than the range specified by the World Health Organization (WHO). The Cadmium and Arsenic levels, Total heterotrophic bacteria count and Total coliform count were above the WHO recommended limits. A total of four genera of bacteria were isolated from the water samples. Correlational analysis revealed no significant (p > 0.05) relationship between the physicochemical parameters and bacteriological properties of water obtained from River Ogio. The water obtained from River Ogio is considered unsafe for domestic consumption due to its high heavy metal content and bacteria load. [ABSTRACT FROM AUTHOR]

There is a vital need and constraint for providing water of good quality all around the world. Thus, with the aim of groundwater treatment, different methods of water treatment have been reviewed. Considering modern methods of membrane filtration, in this study efficiency of nanofiltration for removing heavy metals (copper and chromium) has been examined. The investigation has been accomplished in two separate phases for removing copper and chromium. To prepare the samples of groundwater, urban waters have been utilized and for preparation of chromium‐contaminated and copper‐contaminated waters, powder of chromium‐oxide and powder of copper sulfate pentahydrate have been added into samples, respectively. In this research, system‐operating pressure has been changed, while concentration and pH were kept constant. The effect of pressure on the efficiency of heavy metals removal has been checked and optimum pressure of the process has been achieved. Then, with optimal pressure as system operating pressure, the removal of heavy metals in different pH have been checked and accordingly, the optimal pH for the process was obtained. The Optimum Pressure and pH for chromium and copper are 7.5 bars and 6.3, and 7.5 bars and 6.7, respectively. Taking into account the result of this study, Nano filtration is a suitable method with high efficiency (90% and higher in optimum pressure and pH) for the removal of heavy metals from groundwater. [ABSTRACT FROM AUTHOR]