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15 pages, 2379 KiB

Open AccessArticle

Influence of Blending High-Calcium Additive on Environmental Safety of B, F, and Se: A Case Study from Thermodynamic Calculation

by Ulung Muhammad Sutopo, Erda Rahmilaila Desfitri, Yukio Hayakawa and Shinji Kambara

Environments 2024, 11(2), 32; https://doi.org/10.3390/environments11020032 - 04 Feb 2024

Viewed by 1400

Abstract

Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer [...] Read more.

Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer systems and soil. To study the transformation of TEs, a thermodynamic calculation (FactSage 7.2) was used. Paper sludge ash was used as a calcium compound additive. The influence of blending a high-calcium additive on the environmental safety of TEs was investigated based on the effect of the mass addition ratio of PS ash. This study’s results confirmed that the leaching processes of TEs, namely (CaO)₂(Al₂O₃), CaF₂, Ca₁₀(PO₄)F₂, and CaSeO₄(H₂O)₂, were caused by the formation of B, F, and Se compounds during the leaching process. Thus, it is clear that calcium has the greatest influence on the transformation of TEs due to their reaction, which, in turn, minimizes the effects of the TEs’ release into the environment. The concentrations of TEs from the sample and addition of PS ash decreased slightly, indicating that the inhibition of TEs was enabled through the addition of PS ash. Although the PS ash YB had the highest calcium content, the PS ash YC gave the best results during the B and Se inhibition processes. The experimental observation was also evaluated for comparison. For the analysis of TEs’ leaching ratios using the thermodynamic calculation and experiment, the experimental results were lower than those initially predicted. These results will help us to choose the best available control technology to minimize the effects of TEs released into the environment. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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21 pages, 30021 KiB

Open AccessArticle

Spatiotemporal Assessment of Soil and Vegetation Pollution with Toxic Metals from Road Traffic along the First Romanian Highway

by Luoana Florentina Pascu, Bogdan Adrian Stănescu, Marian Gabriel Gâsnac and Lidia Kim

Environments 2024, 11(1), 21; https://doi.org/10.3390/environments11010021 - 20 Jan 2024

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Abstract

The present study is dedicated to the assessment of soil and vegetation pollution with toxic metals on a section of the oldest highway in Romania, which has been in operation for more 50 years. In the assessment, the limits of the national legislation [...] Read more.

The present study is dedicated to the assessment of soil and vegetation pollution with toxic metals on a section of the oldest highway in Romania, which has been in operation for more 50 years. In the assessment, the limits of the national legislation were complied with, and the analysis was related to locally identified reference levels at a distance from the road, the main potential source of pollution. The average concentrations of toxic metals in the investigated soils had wide amplitudes, and the variations were quite large. The recorded values of the concentrations were at high or moderate levels compared to those in previous research. The contamination factor, geo-accumulation index and other calculated indices indicate the presence of pollution at a moderate level. The concentrations of toxic metals in the range 0.15–0.42 mg/kg d.m. for Cd; 2.00–6.04 mg/kg d.m. for arsenic, 16.20–76.27 mg/kg d.m. for Cu, 17.40–28.40 mg/kg d.m. for Ni, and 149.00–535.00 mg/kg d.m. for Zn exceeded the reference levels in the soil in at least one studied area. The concentrations of Zn at two observation points exceeded the alert threshold, indicating the presence of pollution caused by road traffic. Among the factors that can influence pollution, the following can be distinguished: the specifics of the areas and the activities carried out, the increase in cars transiting the highway, and the location in relation to the entrance or exit areas of the highway. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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17 pages, 1696 KiB

Open AccessArticle

Effect of Soil Aging on Cadmium Bioavailability and Bioaccessibility at a Contaminated Site

by Gianniantonio Petruzzelli, Meri Barbafieri, Elisabetta Franchi, Danilo Fusini, Marco Vocciante and Francesca Pedron

Environments 2023, 10(6), 105; https://doi.org/10.3390/environments10060105 - 20 Jun 2023

Cited by 2 | Viewed by 1803

Abstract

The effect of aging on cadmium (Cd) bioavailability and bioaccessibility was investigated in naturally aged field soil within a contaminated site. The results, which are based on a comparison of investigations carried out in 2018 and 2022 on the same soil samples, provide [...] Read more.

The effect of aging on cadmium (Cd) bioavailability and bioaccessibility was investigated in naturally aged field soil within a contaminated site. The results, which are based on a comparison of investigations carried out in 2018 and 2022 on the same soil samples, provide a realistic evaluation of the variation in Cd chemical forms due to long-term aging. The data obtained show a significant reduction (from approximately 30% to 60%) in the mobile and bioavailable forms of cadmium, while the total quantity in soil did not change significantly. The effect of aging on the bioavailable fractions is also reflected in the reduction in the amount of the metal absorbed by plants. On the one hand, this indicates a reduction in the potential contamination of the food chain, while on the other, it highlights the limitations of the use of phytoextraction as a clean-up technology in this specific site. In the case under study, it should also be noted that there was no decrease in cadmium bioaccessibility over time, which remained very high even after four years of cadmium aging in the soil, which was about 60% of the total content in the most contaminated soil samples. This highlights the potential health risks related to the incidental ingestion of Cd-contaminated soil, which could become the main exposure route in the case of the final use of the site as a park or public green area. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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13 pages, 1899 KiB

Open AccessArticle

Investigation of the Ozonation of Highly PAXHs Contaminated Soil Using Ultrahigh Resolution Mass Spectrometry

by Ilker Satilmis and Wolfgang Schrader

Environments 2023, 10(2), 18; https://doi.org/10.3390/environments10020018 - 26 Jan 2023

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Abstract

Ozonation is an effective chemical treatment technique for removing contamination from the environment. In some countries it is used to clean up drinking water instead of using chlorinated treatment. The contamination of soil with polyaromatic compounds (PAXHs with X = N, S or [...] Read more.

Ozonation is an effective chemical treatment technique for removing contamination from the environment. In some countries it is used to clean up drinking water instead of using chlorinated treatment. The contamination of soil with polyaromatic compounds (PAXHs with X = N, S or O) are some almost forgotten contaminants but describe very toxic and by now almost omnipresent chemical contaminations. The extremely high number of different PAXHs are strongly adsorbed on soil and a method is introduced where an organic solvent is used to facilitate the reaction of the contaminant with ozone. In this study ozone is applied for 6 or 18 h with addition of toluene and the different phases (organic, water, and extract of soil phase) are studied to understand the ozonolysis of polycyclic aromatic hydrocarbons and their derivatives. The reaction is studied using ultrahigh resolution mass spectrometry (UHRMS) allowing a comprehensive characterization of the initial contaminants as well as the various oxidation products. The results show that the ozonation treatment leads to continuous degradation of already oxidized compounds and a wide range of oxidation products can be detected. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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14 pages, 2150 KiB

Open AccessArticle

Nickel and Chromium Origin in Fluvisols of the Petruševec Well Field, Zagreb Aquifer

by Stanko Ružičić, Borna-Ivan Balaž, Zoran Kovač, Lana Filipović, Zoran Nakić and Jasna Kopić

Environments 2022, 9(12), 154; https://doi.org/10.3390/environments9120154 - 09 Dec 2022

Cited by 2 | Viewed by 2903

Abstract

Soil plays an important role in the accumulation and transport of potentially toxic elements (PTEs), from surface into aquifer. PTEs can get to the environment naturally, but also from different kinds of contamination sources. In this study, a soil profile located in the [...] Read more.

Soil plays an important role in the accumulation and transport of potentially toxic elements (PTEs), from surface into aquifer. PTEs can get to the environment naturally, but also from different kinds of contamination sources. In this study, a soil profile located in the vicinity of well field Petruševec, one of the most important well fields related to the public water supply of the City of Zagreb, was analyzed. The main aim of this study was to determine soil properties which can influence retention/mobilization of Ni and Cr in alluvial soil, as well as to define their origin in the investigated soil profile. Results suggest that Cr is geogenic, while Ni is probably of dominantly anthropogenic origin. Observed concentrations, enrichment factors and I_geo values showed no enrichment for Cr, while for Ni, they showed minor to very severe enrichment, i.e., that in some soil horizons, moderate to strong pollution exists. Evaluation of wind directions and location of possible contamination sources that prevail in the study area suggest that Ni can come by aerodeposition from different sources. Results showed that mineral composition can have important influence on retention of analyzed PTEs. Soil horizons, which have very high concentrations of Ni, in general have higher proportion of clay minerals, especially chlorites, as well as Fe oxyhydroxides which can act as an adsorption phase for the investigated PTEs. Results suggest that more detailed research about the investigated PTEs presents a necessity if measures for soil and groundwater protection want to be effectively implemented. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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15 pages, 2160 KiB

Open AccessArticle

Comparative Evaluation of Technologies at a Heavy Metal Contaminated Site: The Role of Feasibility Studies

by Francesca Pedron, Martina Grifoni, Meri Barbafieri, Elisabetta Franchi, Marco Vocciante and Gianniantonio Petruzzelli

Environments 2022, 9(11), 139; https://doi.org/10.3390/environments9110139 - 08 Nov 2022

Cited by 3 | Viewed by 2735

Abstract

Many agricultural areas are contaminated by heavy metals to such a level that the growth of plants is drastically reduced. Based on the site’s specific characteristics, feasibility studies were carried out to choose the most effective technologies. Feasibility tests showed that soil washing [...] Read more.

Many agricultural areas are contaminated by heavy metals to such a level that the growth of plants is drastically reduced. Based on the site’s specific characteristics, feasibility studies were carried out to choose the most effective technologies. Feasibility tests showed that soil washing and phytoremediation technologies could be used at the agricultural site under study. The efficiency of the technologies is highly dependent on soil characteristics, which determine the chemical form of the metals. The results indicate that water-based soil washing can be successfully used with the possibility of reaching the remediation objectives quickly. However, the technology in the first step essentially breaks down the soil. Moreover, phytoremediation cannot be used directly to overcome the toxicity derived from the very high bioavailability of the heavy metals. Still, there is the need to use “assisted” phytoremediation by adding compost that reduces metal bioavailability, allowing phytoextraction. In this case, a longer time is needed to reach the remediation target. The results provide a preliminary scenario for decision-makers and stakeholders to assess possible technologies applicable and a possible scheme to be applied in similar cases of polluted agricultural areas. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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18 pages, 3388 KiB

Open AccessArticle

Assessment of Soil Physicochemical Characteristics and As, Cu, Pb and Zn Contamination in Non-Active Mines at the Portuguese Sector of the Iberian Pyrite Belt

by Paula Alvarenga, Clarisse Mourinha, Patrícia Palma, Nuno Cruz and Sónia Morais Rodrigues

Environments 2022, 9(8), 105; https://doi.org/10.3390/environments9080105 - 17 Aug 2022

Cited by 3 | Viewed by 3664

Abstract

This study aimed to evaluate soil physicochemical characteristics (pH, electrical conductivity, organic matter, total N, and extractable P and K), and potentially toxic elements (As, Cu, Pb, and Zn), in non-active mines located in the Portuguese sector of the Iberian Pyrite Belt (IPB). [...] Read more.

This study aimed to evaluate soil physicochemical characteristics (pH, electrical conductivity, organic matter, total N, and extractable P and K), and potentially toxic elements (As, Cu, Pb, and Zn), in non-active mines located in the Portuguese sector of the Iberian Pyrite Belt (IPB). A total of 70 sampling sites were surveyed at Aljustrel and Lousal, in areas already rehabilitated, and at São Domingos, where rehabilitation was only beginning. The soils at São Domingos were very heterogeneous, with extreme values for some properties (e.g., minimum soil pH 2.0 and maximum As concentration, 4382.8 mg kg⁻¹ dry weight basis (DW)). Aljustrel was the site that presented soils with a higher total As, Cu, Pb, and Zn concentration (median values: 441.5, 545.9, 1396.8, and 316.5 mg kg⁻¹ DW, respectively), above the soil quality guidelines values proposed by the Portuguese Environmental Agency (18, 230, 120, and 340 mg kg⁻¹ DW, respectively). A principal component analysis identified the most relevant soil properties to explain the data variance, which were the soil pH and Pb total concentration, followed by Cu and Zn total concentrations, allowing a separation of Aljustrel from the other mines. Pearson correlation coefficients revealed very strong associations between Pb and As, markedly found at higher concentrations in São Domingos, whereas Aljustrel had an elevated concentration of As and Pb, but also of Cu and Zn. It is evident the risk that persists in the Aljustrel mine area, which was not alleviated by the “dig, dump, and cover” techniques that were implemented to rehabilitate the area. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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Other

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19 pages, 847 KiB

Open AccessSystematic Review

The Impact of Exposure to Hexavalent Chromium on the Incidence and Mortality of Oral and Gastrointestinal Cancers and Benign Diseases: A Systematic Review of Observational Studies, Reviews and Meta-Analyses

by Konstantinos Katsas, Dimitrios V. Diamantis, Athena Linos, Theodora Psaltopoulou and Konstantinos Triantafyllou

Environments 2024, 11(1), 11; https://doi.org/10.3390/environments11010011 - 04 Jan 2024

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Abstract

Background: Limited evidence suggests a possible connection between natural or occupational exposure to chromium and an increased risk of gastrointestinal cancer. The main objective of this study is to investigate the literature regarding chromium exposure and gastrointestinal health issues (i.e., cancer). Methods: A [...] Read more.

Background: Limited evidence suggests a possible connection between natural or occupational exposure to chromium and an increased risk of gastrointestinal cancer. The main objective of this study is to investigate the literature regarding chromium exposure and gastrointestinal health issues (i.e., cancer). Methods: A systematic literature search was performed using PubMed, Google Scholar and ScienceDirect. Included observational studies were assessed for their risk of bias. Results: 16 observational studies and 7 reviews and meta-analyses met the inclusion criteria. Most of the studies investigated gastric and hepatocellular cancer, followed by colorectal, oral, esophageal and pancreatic cancer. There is a limited amount of evidence regarding non-malignant gastrointestinal diseases. Chromium exposure is suspected to increase gastric and colorectal cancer risks. We did not find any convincing indications for increases in oral, esophageal and hepatocellular cancer. Pancreatic, gallbladder and extrahepatic bile ducts carcinogenesis is likely not associated with chromium exposure. Conclusion: We found weak evidence that chromium exposure is associated with gastric and colorectal cancer. Our review also highlights the existing controversial evidence regarding oral, esophageal and hepatocellular cancer, as well as the gap in studies investigating small intestinal cancer and non-malignant gastrointestinal health issues. Full article

(This article belongs to the Special Issue Heavy Metal and Potentially Toxic Elements (PTE) Contamination of Soil)

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