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![Basic unit process of hydrometallurgical metal extraction (modified from [145]).](publication/360379948/figure/fig2/AS:1160727163355137@1653750329250/Basic-unit-process-of-hydrometallurgical-metal-extraction-modified-from-145.png)
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Contamination by heavy metals is a significant issue worldwide. In recent decades, soil heavy metals pollutants in China had adverse impacts on soil quality and threatened food security and human health. Anthropogenic inputs mainly generate heavy metal contamination in China. In this review, the approaches were used in these investigations, focusin...
Contexts in source publication
Context 1
... mechanical-physical, dismantling, pyrometallurgy, or hydrometallurgy can create and discharge heavy metals (e.g., Cu, Pb, Cd, Cr) and persistent organic pollutants (POPs) during recycling and deep extraction for precious resources (e.g., polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and polychlorinated dibenzo-p-dioxins and dibenzofurans) [144]. Hydrometallurgy can be divided into leaching, concentration and purification, and metal recovery [145] (Figure 3). Toxics 2022, 10, 231 18 of 31 traction for precious resources (e.g., polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and polychlorinated dibenzo-p-dioxins and dibenzofurans) [144]. ...
Context 2
... 2022, 10, 231 18 of 31 traction for precious resources (e.g., polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, and polychlorinated dibenzo-p-dioxins and dibenzofurans) [144]. Hydrometallurgy can be divided into leaching, concentration and purification, and metal recovery [145] (Figure 3). Leaching is the process of immersing a precious metal in aqueous solutions containing a lixiviant. ...
Context 3
... preaching, heap leaching, and vat leaching are the three essential leaching processes. Bioleaching may be a viable alternative treatment approach for solid waste materials with low concentrations of valu- Figure 3. Basic unit process of hydrometallurgical metal extraction (modified from [145]). ...
Citations
... Additionally, research is ongoing to optimize soil conditions and identify soil amendments that can enhance plant growth and contaminant removal [125]. 10.2 Developing new phytoremediation techniques: Phytoremediation methodologies have experienced considerable advancements over time, with novel approaches consistently emerging [126]. One of the recent innovations involves utilizing genetically modified plants to augment their contaminant removal capabilities [127]. ...
Phytoremediation, the process of using plants to clean up environmental pollutants, is becoming increasingly popular due to its eco-friendly nature, sustainability, and cost-effectiveness. This research delves into the potential of phytoremediation in handling different types of pollution, such as heavy metals, radioactive substances, pesticides, and organic chemicals. We explore the inner workings of phytoremediation, shedding light on mechanisms like phytoextraction, rhizofiltration, phytostabilization, phytodegradation, and phytovolatilization. Our research also delves into the genetic and molecular structures that enable these processes in various plant species. Despite its promise, phytoremediation has its hurdles. For instance, there's a risk of bioaccumulation, and the method can only treat a limited selection of contaminants effectively. Our study ends with a look at the future trajectory of phytoremediation, placing special emphasis on the potential role of genetic engineering in amplifying its effectiveness and broadening its scope. Ultimately, our research underscores that, when employed properly, phytoremediation can provide an eco-friendly solution for handling and rehabilitating polluted sites. This contributes to the broader goal of sustainable development and preserving environmental health
... They are released into the environment through various anthropogenic activities such as mining, metallurgy, industrial processes, and agricultural practices (2,3). Heavy metal pollution in water sources poses a serious threat to human health and the environment due to their non-biodegradable nature and tendency to accumulate in living organisms (4,5). Heavy metals such as Cr (IV), Cd (II), Ni (II), As (III & V), Pb (II), Cu (II), Zn (II), Sb (II), Hg (II), and Se (II) are highly toxic to living organisms (6). ...
Several industries such as leather tanning, coal mining, steel and metal processing are responsible for heavy metals contamination in water. Heavy metals contamination in water can have harmful effects on both aquatic and terrestrial animals by entering the food chain. Due to the higher toxicity of heavy metals, it is necessary to remove heavy metal ions from water. There are several physio-chemical methods available, including ion exchange, membrane filtration, chemical oxidation, and electrochemical methods. However, these methods have some disadvantages like expensive and generating harmful byproducts. Biosorption is a cost-effective and eco-friendly method for the removal of heavy metals from contaminated water. Biosorbents are derived from biomasses of plant, bacterial, algal, fungal, agro-waste, etc. The biosorbents have several functional groups on their surface providing them a high binding capacity for heavy metal ions. Mathematical models such as isotherms, thermodynamics, and kinetic studies help explain how heavy metals adsorb on biosorbents. This review provides comprehensive details on the heavy metals heavy metal contaminated in water including the source, toxicity and biosorption of heavy metal ions. This review also provides the mechanism of heavy metal biosorption including mathematical models.
... It is estimated that about 750 million tons of mining waste, out of about 378 million tons of flotation tailings [3], is deposited near the city of Bor during the exploitation period. This waste contains hazardous and potentially toxic elements such as copper, nickel, arsenic, zinc, antimony, mercury, chromium, bismuth, and other pollutants [4]. Besides polluting the environment, these pollutants are very toxic to human health and can cause a large number of diseases and even death in cases of very high doses when acute poisoning occurs [5][6][7][8][9][10][11][12]. ...
This paper considers the impact of copper mining-influenced water and metallurgical wastewater on the surface water in the Bor area, Serbia. Sampling, realized through the four campaigns (2020–2021), confirmed that both types of water, discharged without appropriate treatment in the Bor River, had a signific impact on the concentration of metal ions, pH and electrical conductivity on the watercourse in the Bor area. The highest concentrations of the following metal ions, Cu-271 mg/L, As-25991 μg/L, Ni-13856 μg/L, Cd-2627 μg/L, and Pb-2855 μg/L, were registered in the metallurgical wastewater samples. After changes occurred in the copper production process by stopping the discharge of untreated wastewater into the Bor River, the concentrations of monitored elements were drastically decreased. In the period 2022–2024, the concentration values for Cu, As and Pb ions were below the maximum allowable value, and the concentration values of Ni and Cd ions were also decreased. The values for pH and electrical conductivity were in the maximum allowable range. The return of wastewater to the copper production process would lead to both a reduction in the primary water consumption and reduction in the negative impact on the environment.
... For example, the production of clothing involves the utilization of raw materials with high levels of Ni and Cr [9]. Soils near chlor-alkali factories carry high levels of Hg [10], while lead smelters are associated with high levels of Pb contamination in top soils [11]. Therefore, it is necessary to make accurate judgments of potential emissions instead of identifying natural or industrial source types. ...
Current source apportionment models have successfully identified emission sources and quantified their contributions. However, when being utilized for heavy metal source apportion in soil, their accuracy needs to be improved, regarding migration patterns. Therefore, this work intended to improve the pre-existing principal component analysis and multiple linear regression with distance (PCA-MLRD) model to effectively locate pollution pathways (traffic emissions, irrigation water, atmospheric depositions, etc.) and achieve a more precise quantification. The dataset of soil heavy metals was collected from a typical area in the Chang-Zhu-Tan region, Hunan, China in 2021. The identification of the contribution of soil parent material was accomplished through enrichment factors and crustal reference elements. Meanwhile, the anthropogenic emission was identified with principal component analysis and GeoDetector. GeoDetector was used to accurately point to the pollution source from a spatial differentiation perspective. Subsequently, the pollution pathways linked to the identified sources were determined. Non-metal manufacturing factories were found to be significant anthropogenic sources of local soil contamination, mainly through rivers and atmospheric deposition. Furthermore, the influence of irrigation water on heavy metals showed a more pronounced effect within a distance of 1000 m, became weaker after that, and then gradually disappeared. This model may offer improved technical guidance for practical production and the management of soil heavy metal contamination.
... The rapid development of industrial activities has led to a substantial rise in soil-groundwater heavy metals (HMs) contamination in recent years. Nonferrous smelting activities, which cause HMs pollution, contamination from solid waste accumulation, and other environmental hazards, are among the most important sources of toxic metals in soil [1]. Soil-groundwater contamination stems from long-term filtration and leaching of solid wastes and contaminated soil through rainfall, releasing large amounts of Cd, Cu, Pb, Zn, and other HMs into the surrounding environment through surface runoff and groundwater migration. ...
The topsoil of smelter sites is subjected to severe contamination by heavy metals (HMs). Existing numerical simulations typically treat soil and groundwater separately owing to data limitations and computational constraints, which does not reflect the actual situation. Herein, a three-dimensional coupled soil-groundwater reactive solute transport numerical model was developed using the Galerkin finite element method with the smelter as the research object. This model treats soil and groundwater as a whole system, providing a quantitative characterization of HMs migration patterns in soil and groundwater. The model used the reaction coefficient (λ) and retention coefficient (R) to describe the release and adsorption capacities of HMs. Results from the model were consistent with actual pollution distributions in the field, indicating the efficacy of the soil-groundwater remediation technology for severe soil and localized groundwater pollution. The constructed three-dimensional coupled soil-groundwater reactive solute transport model can describe and predict the distribution and transport diffusion behavior of HMs at the study site with good efficacy. The model was also used to simulate and predict the effects of remediation technologies during the treatment of smelting site contamination, providing guidance for optimizing the treatment plan.
... Wang, Walker, Muir, & Nagatani-Yoshida, 2020). One primary route through which anthropogenic pollutants enter food crops and livestock is when agricultural practices take place in proximity to pollution sources, such as when soil is contaminated by nearby industrial activity or when irrigation relies on water tainted with pollutants (Adnan, et al., 2022). Large-scale investigations have shown the negative impacts of pesticide residues on soil, terrestrial, and aquatic ecosystems, and positive correlations with the risk of neurological and reproductive diseases and cancer, and veterinary drug residues have been proven to cause drug-induced deafness, liver and kidney damage, bacterial imbalance, and carcinogenic effects (Bacanli & Basaran, 2019;Carvalho, 2017;Thompson et al., 2017). ...
Background
With the influence of climate change, environmental pollution, global industrialization, and new agricultural practices, increasing amounts of chemical substances with potential risks—both anthropogenic and biogenic—enter the food supply chain, entailing new challenges to food safety and security. Although some food-risk components (FRCs) have been accessed and regulated, the toxicity and exposure level of the numerous components detected in food remain unknown, leaving questions on their effect on food safety. Therefore, multiple databases on emerging FRCs have been constructed to aid in food safety assessment, regulation, and communication; however, their focus areas, data content, quality, and accessibility have not been systematically summarized, which hinders their applications and the development of data-driven methods in the food safety field.
Scope and approach
The major objective of this review is to introduce representative FRC databases with different focus areas, along with their chemical presentation, data quality and availability, and successful applications.
Key findings and conclusions
Over the past decades, over 50 FRC databases have been released, contributing significantly to scientific research, policymaking, and education. However, our analysis unveils persistent challenges such as delayed updates, accessibility concerns, reproducibility issues, suboptimal data quality, and inadequate coverage in underdeveloped regions. To address these shortcomings, we propose an initiative aimed at enhancing future FRC databases, prioritizing the principles of findability, accessibility, interoperability, and reusability. Additionally, we highlight the potential of future strategies, e.g., natural language processing, cheminformatics-enpowered suspect and non-targeted analysis, and genome mining, for the detection and analysis of emerging new FRCs outside of existing databases. By embracing these initiatives and strategies, we lay the groundwork for a robust framework facilitating enhanced food safety assessment and informed decision-making in the face of evolving challenges.
... The complex effects of various factors depend on the pH of the soil, the content of organic substances, soil texture, redox conditions, moisture and drainage, and anthropogenic activities. Overall, complex interactions between soil properties, environmental conditions, and anthropogenic activities determine the fate and behaviour of heavy metals in the soil [3,6,7]. ...
This study examined the sorption of heavy metals in selected soils (e.g., Andosol, Cambisol, Planosol) in Slovakia, focusing on the kind and quantity of humic materials as well as the soil’s characteristics. Heavy metals were detected using GT AAS, while UV-Vis spectroscopy was used to determine humic substances’ colour quotients. The impact of the total organic carbon on the total cadmium, bioavailable lead, and cadmium was highlighted. The results reveal positive correlations among humic substances and bioavailable forms of Cd (r = 0.692) and Pb (r = 0.709). A relationship was discovered between FAs and the bioavailable forms of Pb (r = 0.743) and Cd (r = 0.700) and between the level of HSs and the bioavailable content of Cd (r = 0.499). Bioavailable heavy metals showed a positive correlation with clay fraction and a negative correlation with heavy metal content. Correlations were found between the bioavailable heavy metal forms and the colour quotients of humic substances and humic acids. Heavy metals in bioavailable forms decreased with the levels of the condensation and dispersion of humic substances. From clay to silt, the amounts of Cd and Pb increased. This study’ results provide insights into the relationships between soil properties, humic substances, and the sorption of the studied elements.
... The numerical results are an indicator of the different levels of contamination. According to Adnan et al. [75] EF bellow 2 means no or minimal enrichment; between 2 and 5, moderate enrichment; between 5 and 20, significant enrichment; between 20 and 40, very high enrichment and EF above 40, extremely high enrichment. ...
... The enrichment factor was calculated using the formula originally introduced by Adnan et al. [75] and Buat-Menard and Chesselet [76] as shown in Equation (1). ...
The study was carried out to define the distribution of mercury in surface soils in the Mitrovica region, Republic of Kosovo and to assess the level and extent of contamination. A total of 156 soil
samples were collected from a depth of 5 cm at each grid point of 1.4x1.4 km in an area of 301.5km2. The mercury content was found to be between 0.02 mg/kg and 11.16 mg/kg. The average
Hg content (0.49 mg/kg) exceeded the mean content in European (0.037 mg/kg) and world (0.06 mg/kg) soils by 13.2 and 8.2 times, respectively. From the calculated enrichment factors (EF) and the geo-accumulation index (I-geo), as well as from the distribution map of Hg content, it is evident that the soils of the study area are highly contaminated with mercury, with extremely high enrichment of Hg in the soils of Zone I, which was classified as the most contaminated zone with Hg and other potentially toxic elements in the study area as well as in the towns of Zvecan and Mitrovica. The higher Hg content is of anthropogenic origin, mainly due to lead and zinc mining and metallurgical activities in the study area. The mercury levels were also found to exceed the New Dutch List target value (0.3 mg/kg) in 90km2 of the study area.
... "Heavy metals" is a term commonly associated with pollution and potential toxicity or ecotoxicity and refers to a specific group of substances that possess metallic properties, including both metals and semimetals; however, metal(loids) of environmental significance include asbestos, cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), molybdenum (Mo), zinc (Zn), thallium (Tl), antimony (Sb), and various others (Li et al., 2019a(Li et al., ,2019bVamerali et al., 2010). Heavy metals are "those whose density exceeds 5 g per cubic centimeter" (Adnan et al., 2022a(Adnan et al., ,2022bAli and Khan, 2018;Chen et al., 2021;Feng and Wu, 2023). Due to its similar environmental reactivity and common chemical features, the metalloid arsenic (As) is frequently categorized as an HM (Ayyanar and Thatikonda, 2020;Blasi et al., 2012;Chen et al., 2015). ...
... The rapid modernization process in China has resulted in a notable concern regarding the poisoning of agricultural land by HMs. In China, a significant proportion of agriculturally polluted soils, estimated at around 82%, contain toxic inorganic pollutants such as Pb, Cd, Cr, and As (Adnan et al., 2022a(Adnan et al., ,2022bChen et al., 2014). The values obtained were significantly higher than those reported in prior investigations conducted outside China. ...
Throughout the literature, the word "heavy metal" (HM) has been utilized to describe soil contamination; in this context, we characterize it as those elements with a density greater than 5 g per cubic centimeter. Contamination is one of the major global health concerns, especially in China. China's rapid urbanization over the past decades has caused widespread urban water, air, and soil degradation. This study provides a complete assessment of the soil contamination caused by heavy metals in China's mining and smelting regions. The study of heavy metals (HMs) includes an examination of their potential adverse impacts, their origins, and strategies for the remedi-ation of soil contaminated by heavy metals. The presence of heavy metals in soil can be linked to both natural and anthropogenic processes. Studies have demonstrated that soils contaminated with heavy metals present potential health risks to individuals. Children are more vulnerable to the effects of heavy metal pollution than adults. The results highlight the significance of heavy metal pollution caused by mining and smelting operations in China. Soil contaminated with heavy metals poses significant health concerns, both carcinogenic and non-carcinogenic, particularly to children and individuals living in heavily polluted mining and smelting areas. Implementing physical, chemical, and biological remediation techniques is the most productive approach for addressing heavy metal-contaminated soil. Among these methods, phytoremediation has emerged as a particularly advantageous option due to its cost-effectiveness and environmentally favorable characteristics. Monitoring heavy metals in soils is of utmost importance to facilitate the implementation of improved management and remediation techniques for contaminated soils.
... It is among the well-established HMs with detrimental effects on the aquatic ecosystem, contributing to potential toxicity to living organisms and persistent environmental concerns (Abd Elnabi et al., 2023). The toxicity of Cd is contingent upon diverse factors, such as the specific form of metal, pH levels, oxidation state, concentration, interval of exposure, and other variables (Adnan et al., 2022). One of the primary concerns in the realm of metal toxicity is the issue of incremental soil contamination by Cd. ...
... Accumulated Cd in the soil and rocks may be carried downstream by rivers and eventually end up in the ocean (Mahajan et al., 2022). The primary anthropogenic origin of Cd comes from the extraction and refining of metallic elements such as zinc (Zn), lead (Pb), and copper (Cu) (Adnan et al., 2022). The use of phosphate fertilizers also has the potential to introduce Cd into agricultural soils resulting in possible accumulation in soil and plants with frequent application (Niño-Savala et al., 2019). ...
