Heavy Metals Research Articles

Roles of different mineral seeds in heavy metals removal/recovery from simulated and actual acid mine wastewater

Roles of different mineral seeds in heavy metals removal/recovery from simulated and actual acid mine wastewater

Facile Synthesis of Polypyrrole-Decorated RGO-CuS Nanocomposite for Efficient Nickel Removal from Wastewater

Efficient wastewater treatment, particularly the removal of heavy metal ions, remains a challenging priority in environmental remediation. This study introduces a novel sandwich-structured nanocomposite, RGO-CuS-PPy, composed of reduced graphene oxide (RGO), copper sulfide (CuS), and polypyrrole (PPy), synthesized via a straightforward hydrothermal method. The unique combination of RGO, CuS, and PPy offers enhanced adsorption capacity for Ni(II) ions due to RGO’s high surface area and CuS’s active binding sites, supported by PPy’s structural stability contributions. This study is among the first to explore this specific nanocomposite architecture for Ni(II) removal, achieving an adsorption capacity of 166.67 mg/g and a high removal efficiency of 94.9% within 210 min for 55 mg/L of Ni(II) concentration at pH 6 and adsorbent dose of 3 mg/15 mL. The kinetic analysis shows the best fitted time-dependent experimental data with the pseudo-second-order model, indicating chemisorption. Isotherm studies confirmed the Langmuir model as the best fit, yielding a high monolayer adsorption capacity of 166.67 mg/g. Thermodynamic analysis shows the adsorption process was endothermic (ΔH° = 80.23 kJ/mol) and spontaneous (ΔG° ranging from −6.985 to −14.399 kJ/mol). Additionally, reusability tests using 0.1 M HCl for desorption demonstrated good reusability, emphasizing the RGO-CuS-PPy nanocomposite’s potential as a sustainable adsorbent for Ni(II) removal in wastewater treatment applications.

Applications of bio-composites in electronics

Abstract Functional biomaterials are being used in many promising industries to improve human quality of life and advance environmental objectives. Consideration has been given to many applications in the domains of medical, electronics, food, and pharmaceuticals. The use of bio-inspired materials enables the creation of more sustainable alternatives that strive to advance environmental preservation while simultaneously ensuring customer satisfaction. It was discovered that biopolymers are used in a number of different industries for the production of a wide range of functional bio-products. These bio-products include organic thin film transistors, organic phototransistors, emitting diodes, photodiodes, photovoltaic solar cells, hybrid dental resins, sustainable medicines, and consumer food packaging. A growth of this magnitude makes it possible to conduct substantial research in order to more inspection of the limitless requests and uses of bio-based composites. In order to fulfill the needs of certain applications, it is necessary to adjust and reassess attributes and parameters– such as hardness, durability, crack toughness, binding, solubility, polarization, plasticity, hydrogen bonding, thermal characteristics, and dielectric behavior. By virtue of their electronic and electrical properties, bio-composites and biopolymers have been put to use in a variety of applications; some includes organic thin-film transistors, electrical applications, electromagnetic insulation, energy harvesting, and thermoelectric processes. Substantial proportions of electronic waste, also referred to as E-waste, are regularly released into the environment due to the continuous growth in the production of electronic devices. Consequently, this leads to substantial environmental and ecological problems caused by the release of non-degradable polymers, hazardous compounds, and toxic heavy metals into the environment. The advancement of biodegradable polymers has significant potential for effectively reducing the environmental burden, since they may be decomposed or absorbed into the surrounding environment without generating any toxic effects. Hence, the purpose of this study is to illustrate the creation of biocompatible composites and their prospective uses in electrical applications.

Evaluation of environmental risks by heavy metals pollution and algae accumulations in two alpine lakes

Evaluation of environmental risks by heavy metals pollution and algae accumulations in two alpine lakes

Editorial: Safe utilization of heavy metals pollution in soils for healthy food

Editorial: Safe utilization of heavy metals pollution in soils for healthy food

Pollution characteristics and health risk assessment of heavy metals in PM2.5 in Fuxin, China

Pollution characteristics and health risk assessment of heavy metals in PM2.5 in Fuxin, China

Arsenic Enhances the Degradation of Middle-Chain Petroleum Hydrocarbons by Rhodococcus sp. 2021 Under Their Combined Pollution

The efficient and green remediation of petroleum hydrocarbon (PH) contamination has emerged as a viable strategy for environmental management. Here, we investigated the interaction between arsenic and PH degradation by Rhodococcus sp. 2021 under their combined pollution. The strain exhibited disparate responses to varying concentrations and valences of arsenic. The elevated concentration of arsenic (>100 mg/L) facilitated the degradation of PHs, and there was a positive correlation between arsenic-promoted degradation of PHs and their carbon-chain length. The degradation of PHs changed with arsenic conditions as follows: trivalent arsenic groups > pentavalent arsenic groups > arsenic-free groups (control). Arsenite and arsenate significantly promoted the gene expression of arsenic metabolism and alkane degrading. But unlike arsenite, arsenate also significantly promoted the gene expression of phosphate metabolism. And arsenite promoted the up-regulation of the expression of genes involved in the process of PHs oxidation and fatty acid oxidation. These results highlight the potential of Rhodococcus sp. 2021 in the remediation of combined total petroleum hydrocarbon (TPH) and heavy metal pollution, providing new insights into the green and sustainable bioremediation of combined pollution of organic matters such as PHs and heavy metals/heavy metal-like elements such as arsenic.

Determination of priority control factors for risk management of heavy metal(loid)s in park dust in Mianyang City

In order to determine the priority control elements and sources of heavy metal(loid)s (HMs) pollution in park dust, this study collected dust samples from 25 parks in the urban area of Mianyang City and measured the contents of 10 HMs. Based on Monte Carlo simulation, the probabilistic pollution levels and ecological-health risks of HMs were assessed. We found that the average contents of Zn, Co, Pb, and Cr were much higher than their background values in local soil and were influenced by artificial activities. The pollution assessment found that 5 parks were moderately polluted. The comprehensive pollution of HMs in the dust was mainly caused by Zn and Cr, and industrial source was the main contributor to Zn and Cr pollution. The contribution of As, Co, and Pb to the comprehensive ecological risk was high, accounting for 54.6%. Co, Pb, and As were the priority control HMs of ecological risk, while mixed source and industrial source were the priority control sources. HMs presented potential carcinogenic health risks to both children and adults. The non-carcinogenic risk to adults was within safety level, while some parks showed non-carcinogenic risk to children, which should be paid attention to. The source-specific health risk assessment showed that Cr and As were the priority control HMs for human health, while mixed source and industrial source were the priority control sources.

Ecological Risk of Heavy Metals in an Eco-Industrial Park in China

ABSTRACT To ascertain whether rapid industrialization has affected the accumulation of heavy metals (HMs) in Suzhou Industrial Park (SIP), China, the occurrence and ecological risk of HMs, including Cu, Zn, Pb, Cr, Cd, Ni, As and Hg in sediments were analyzed. The results indicated that total concentrations of HMs (mg kg−1) were in the descending sequence of Zn (235.28) > Cr (95.71) > Cu (78.91) > Ni (55.51) > Pb (23.96) > As (22.12) > Cd (0.38) > Hg (0.14). The concentrations of HMs, except for Ni and Cd, were found to be below the probable effect level (PEL). Correlation analysis (CA) and principal component analysis (PCA) showed that HMs in SIP mainly originated from anthropogenic activities. HMs were mainly in residual fractions (55.5 ~ 95.1%), and the exchangeable fractions of Zn and Cd were relatively high. The risk assessment results indicated that Hg and Cd significantly contributed to ecological risks, whereas Cr and Pb made relatively minor contributions. Our findings indicated that intense anthropogenic activities promote HMs accumulations in streams in SIP during rapid industrialization.

Antioxidants, ACE I Inhibitory Peptides, and Physicochemical Composition, with a Special Focus on Trace Elements and Pollutants, of SPRING Spawning Atlantic Herring (Clupea harengus) Milt and Hydrolysates for Functional Food Applications

Norwegian spring spawning (NVG) herring milt is a raw material with high nutritional and functional values. However, its incorporation into food presents physicochemical and sensory challenges. Its high DNA content, the presence of TMA/TMAO and possibly heavy metal and/or environmental pollutants, and its bitter taste due to amino acids or peptides requires a careful approach to food development. Hydrolysis with food-grade enzymes enable an improvement in both the functional and sensory properties of the substrate and the increased stability of the raw materials and end products. HLPC, GC-MS, and in vitro protocols were used for the characterisation of manually extracted material (sample code: HMC) and milt from a fish-filleting line from early spring/late autumn catches. Three different food-grade protein hydrolysates were prepared from these raw materials (sample codes: H1, H2, and H3) as a means to estimate their functional food development potential. Combinations of three commercial enzymatic preparations were applied, targeting specific sensory properties. Parameters related to consumer safety (e.g., the presence of heavy metals and TMA/TMAO); beneficial health effects, such as antioxidant or antihypertensive bioactivities (measured using in vitro TAC, ORAC, DPPH, and ACE I inhibitory activity assays); the presence of beneficial fatty acids and micronutrients; and the protein quality were studied. On the basis of their total amino acid compositions, freeze-dried herring milt and hydrolysates could provide high-quality protein with most of the essential amino acids and taurine. Powdered milt has a particularly high fatty acid profile of bioavailable omega-3 fatty acids (2024.06 mg/100 g docosahexaenoic acid (DHA; 22:6n-3) and 884 mg/100 g eicosapentaenoic acid (EPA; 20:5n-3)). The experimentally measured levels of arsenic (3.9 ± 1.2 mg/kg) and cadmium (0.15 ± 0.05 mg/kg) were higher than the levels of the other two heavy metals (mercury and lead). The bioactivity is concentration-dependent. Overall, this work presents complementary information for the future utilisation of C. harengus powdered milt (possibly obtained directly from a fish-filleting line) and some of its protein hydrolysates as food ingredients.

Comprehensive analysis of heavy metals and antioxidant properties in various spices and propolis

ABSTRACT In this research, various spices, including curry, fenugreek, allspice, ginseng, abaza herb, nutmeg, mahaleb, coriander, cajun spice, propolis, marjoram, star anise, cardamom, poppy, lavender, tarragon, plantago, vitex seed, French lavender, and yarrow were examined for their trace elements and antioxidant contents. Ethanol extractions were used for DPPH, ABTS, reducing power, and total phenolic content tests, revealing that propolis and plantago exhibited the highest antioxidant and phenolic contents, while fenugreek and cardamom showed the lowest. In the heavy metal analysis, samples were dissolved using a microwave, and trace elements were analysed by ICP-OES. Method accuracy was confirmed with NIST-SRM 1515-Apple Leaves certified reference material. Elemental concentrations ranged from 0.013–27 µg/g for Cu, 29–802 µg/g for Fe, 2.13–430 µg/g for Mn, 0.37–5.00 µg/g for Ni, and 3.13–66 µg/g for Zn. These results were compared with existing literature values. This study highlights the balance needed between the beneficial antioxidant properties and potential risks from trace metals in spices and propolis, emphasising the importance of safety in food consumption.

Cuproptosis: A Copper‐Mediated Programmed Cell Death

It has been found that various heavy metals can initiate different types of regulated cell deaths. Among these metals, copper, an essential trace micronutrient that plays a major role in a lot of physiological processes, also can initiate cell death. It can act as a constituent of metalloenzymes, and can act as a mediator for signaling pathways to regulate proliferation and metastasis of tumor. It is also an integral part of some metal‐based anticancer drugs. Recent studies have revealed that excessive intracellular copper accumulation leads to the aggregation of mitochondrial lipoylated proteins, causing proteotoxic stress and ultimately resulting in cell death. This newly discovered copper‐induced cell death is termed as cuproptosis. In the last few, a lot of research has been done to understand the mechanism of copper‐mediated cell death, and attempts have also been made to identify the relationship between cuproptosis and the development of cancer. In this review, we provide a comprehensive overview on the significance of copper, its regulation inside the body, the possible mechanism of cuproptosis, and how this cuproptosis can be employed as a therapeutic tool for cancer ablation.

Towards Sustainable Battery Recycling: Selective Desorption of Nickel(II) and Cobalt(II) from Amino‐Polycarboxylate Derivate Ligands in Model Systems

AbstractInter alia due to the high demand for lithium‐ion batteries, the required critical heavy metals have become a scarce resource. Consequently, effective recycling processes that enable the recovery of such materials are of high interest. A silica adsorbent functionalized with amino‐polycarboxylate derivate ligands (HSU331) was applied in order to selectively adsorb nickel(II) and cobalt(II). Subsequently, suitable parameters for a pH‐swing desorption were investigated. Maximum desorption efficiencies for Co(II) were achieved at pH = 2.7 (72 %) and for Ni(II) at pH = −0.5 (94 %). These results were used for the design of a pH‐shift desorption process in order to selectively recover Co(II) and regenerate the adsorbent after simultaneous adsorption of Co(II) and Ni(II).

Optimizing food waste bioconversion with sodium selenite-enhanced Lucilia sericata maggots: a sustainable approach for chicken feed production and heavy metal mitigation

Optimizing food waste bioconversion with sodium selenite-enhanced Lucilia sericata maggots: a sustainable approach for chicken feed production and heavy metal mitigation

Fabrication polyaniline via electrochemical synthesis for highly efficient removal of Cr(VI)

AbstractPolyaniline (PANI) is recognized for its exceptional electrochemical conductivity, and its chemical structure, rich in amino and imine functional groups, exhibits significant removal capabilities for heavy metal pollutants in wastewater. In this study, PANI was synthesized via electrochemical cyclic voltammetry, and its micromorphology and phase structure were characterized using SEM, TEM, FTIR, and XRD. By modulating the polymerization potential, control over the surface morphology was achieved, thereby optimizing its adsorption performance. Additionally, the adsorption efficiency of electrochemically synthesized PANI for Cr(VI) in wastewater was assessed. Notably, in acidic conditions, PANI demonstrated an exceptionally high adsorption capacity for Cr(VI), reaching 130.1 mg/g. These findings highlight the potential of conductive polymers such as PANI in the development of highly efficient adsorbents for wastewater treatment, providing tangible solutions for addressing water pollution.

Metallurgical Waste for Sustainable Agriculture: Converter Slag and Blast-Furnace Sludge Increase Oat Yield in Acidic Soils

The study is the first to examine the combined use of blast-furnace sludge as a source of microelements and converter slag as a soil-deoxidizing agent in oat (Avena sativa L.) cultivation in sod-podzolic soils. It has been established that blast-furnace sludge is a highly dispersed waste, which contains about 50% iron, 7% zinc, and a small amount of calcium, silicon, magnesium, aluminum, and sulfur. Hazardous components such as lead, arsenic, etc., are not detected. Converter slag comprises porous granules up to 3 mm in size, consisting mainly of calcium compounds (CaO, Ca(CO)3, CaSiO3, CaFe2O4) and a small amount of Mn, Al, and Mg trace elements. In a laboratory experiment, blast-furnace sludge increased the germination of oats by 5–10%, regardless of the addition of a deoxidizer (slag), but at the same time suppressed the growth of stem length by a maximum of 18% at 1 g∙kg−1. The addition of slag raised substrate pH and increased the index by 8% at a sludge concentration of 0.1 g∙kg−1. Root length in deoxidizer-free variants increased by 50–60% and with the addition of slag by 27–47%. Root dry mass also increased under the addition of sludge by 85–98%; however, the addition of slag reduced the indicator to the control level. In a field experiment with the combined application of waste, an increase in yield by more than 30% was shown. When soil was treated with slag and sludge, the height of plants increased by an average of 18%. It should be noted that the introduction of waste did not affect the quality of the grain. The use of slag increased the lead content in the soil, which is probably due to the sorption properties of calcium compounds in the slag, since lead was not found in the analyzed waste. Presumably, lead is sorbed by slag from the lower soil horizons, concentrating and immobilizing it in the upper layer. This version is supported by the absence of lead accumulation in straw and oat grain. The zinc-containing sludge increased the content of this element by 33% in the soil, as well as by 6% in straw and by 14% in grain. Thus, we found that the studied metallurgical wastes can be used as nutrients for agriculture, both individually and jointly. Overall, the proposed approach will contribute both to reducing the amount of accumulated waste and to improving the efficiency and sustainability of agricultural production and CO2 sequestration. However, the features of the accumulation of heavy metals in soil and plants under the influence of the analyzed types of waste require more in-depth study, including within the framework of long-term field experiments.

Heavy Metal Remediation Using Phosphate-Solubilizing Fungi: From Bioprocess to Application

Heavy metal pollution has been a major environmental issue in recent years, seriously threatening land, water sources, agriculture, and human health. The remediation of heavy metal pollution has been a continuously vital issue for current research. Bioremediation is an effective and cost-efficient approach to reduce heavy metal toxicity. Phosphate-solubilizing fungi (PSF) have shown promise in heavy metal bioremediation due to their high tolerance and activity levels. However, the full potential of PSF in bioremediation needs further exploration. PSF activity, metabolite production, and environmental conditions can influence their efficiency in remediating heavy metals. These factors play a critical role in the practical application of PSF and necessitate improvement pathways. This article reviews potential strategies to enhance heavy metal remediation using PSF and optimizing bioprocesses and applications.

Typha domingensis (Pers.) Poir. ex Steud. Potential to Restore Contaminated Wetlands in Egypt

AbstractSeveral studies have reported Typha domingensis (Typhaceae) as a heavy metal (HM) hyperaccumulator. This study aims to assess the seasonal variations in the accumulation potential of T. domingensis (TD) for HM in polluted wetlands in Greater Cairo, Egypt. Sampling of fresh wild plants from the TD’s subterranean (Root and stem) and surface components were gathered from different polluted sites distributed in the canal of Ismailia and Nahia drain, as well as from the River Nile as an unpolluted site (control). The findings showed that pollution negatively affected the chemical characteristics of sediment and water. Except for the TD’s leaf area, there were significant seasonal variations in the growth characteristics (density, stem diameter, leaf length, and width, fresh and dry biomass). The subterranean parts stored higher amounts of HM than the aboveground shoots. Manganese (Mn) concentration (413.2 mg kg− 1) was greater in the roots of autumn plants, whereas their shoots recorded the highest Pb (225.8 mg kg− 1). Al, Cd, Cu, Fe, Ni, and Zn concentrations in summer plant roots (1499.9, 74.8,1356.1, 3948.8, 403.8, and 1294.2 mgkg− 1, respectively). The factor of metal bioaccumulation (BF) values, was high in TD plants growing in a polluted Ismailia canal, but translocation factor (TF) values for all measured elements were lower than one, except for Pb. Summer is the best season for TD growth to sequester high HM concentrations. The authors recommended that TD be employed to mitigate HM pollution in wetlands and restore them.

Heavy metal contamination and potential health risks in upland rice-producing soils of rotational shifting cultivation in northern Thailand

Rotational shifting cultivation (RSC) is commonly practiced in northern Thailand for upland rice cultivation, primarily for household consumption. However, the potential health risks from heavy metal contamination in these soils have not been thoroughly explored. This study aimed to evaluate the contamination of six heavy metals (Arsenic (As), Mercury (Hg), Cadmium (Cd), Lead (Pb), Copper (Cu), and Chromium (Cr)) in upland rice across RSC fields with varying fallow periods and assess the associated health risks from rice consumption. Four RSC fields with 5, 6, 10, and 12-year fallow periods were examined. The RSC-6Y and RSC-12Y fields were used for upland rice cultivation in 2022, while the RSC-5Y and RSC-10Y fields were cultivated in 2023. The geo-accumulation index (Igeo) was calculated, and translocation factors (TF) were assessed for the transfer of heavy metals from soil to straw (TFStraw/Soil), straw to grain (TFGrain/Straw), and soil to grain (TFGrain/Soil). The results indicated that after burning vegetation in the RSC fields, the highest concentrations of Pb, Cr, and Hg were found in the ash. In RSC soils, Cu, Cr, As, Pb, and Hg levels were below reference standards, with Cd undetected. In rice grains, the order of concentration was Pb > Cu > Cr > As, with Hg and Cd undetected. Pb levels in rice grains exceeded the safety threshold. Igeo values indicated no contamination to moderate contamination across sites, with negative Igeo values for Cr and Cu, and zero values for Cd. The TF results showed limited transfer of As, Hg, and Cd from soil to rice plants (TFStraw/Soil < 0.1), but notable transfer for Pb, Cr, and Cu. Pb was readily transferred from soil to grain (TFGrain/Soil), posing a potential health risk. The study highlights potential non-carcinogenic and carcinogenic risks from heavy metal exposure, particularly Pb, and underscores the need for further research to determine contamination sources and mitigation strategies.

Diagnosis of sensitive leaf types and spectral segments during maize heading stage under simulated copper stress environment in mining areas

ABSTRACT This paper designed CSSDM (Copper Stress Spectral Diagnosis Method) from the perspective of frequency domain, combined with time-frequency analysis, to obtain sensitive leaf types and spectral segments under heavy metal copper stress, providing technical support for heavy metal monitoring in crops. Firstly, the hyperspectral reflectance data of maize leaves under copper stress were subjected to DD (Double Differentiation) and EE (Envelope Elimination), and transformed into the frequency domain. The d6 (Daubechies wavelet 6-layer) decomposition was performed using time-frequency analysis methods. Then, based on the signal anomaly points, wavelet high value points and DDEE (Double Differentiation Envelope Elimination) curve high value points, the SRVP (Spectral Reflectance Variation Parameters) of maize leaves are defined. Finally, by examining the correlation between spectral reflectance variation parameters and heavy metal content in maize leaves, we aim to explore the leaf types and spectral segments that are sensitive to copper pollution. The results showed that CSSDM can efficiently enhance weak information in maize leaves and accurately locate the spectral anomaly caused by heavy metal copper stress, with the anomaly range concentrated within 350 nm−800 nm. Spectral reflectance variation parameters can quantitatively measure the spectral anomalies of maize leaves under heavy metal copper stress. Under different copper stress gradients, maize new leaves exhibit sensitive leaf types, with sensitive spectral segments including Blue Edges, Green Peaks, Yellow Edges and Red Valleys.