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1.
Food Chem ; 367: 130734, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34359003

RESUMEN

Isocycloseram is a new isoxazoline insecticide that can efficiently control the diamondback moth in cruciferous crops. The aim of this study was to establish a method for the determination of isocycloseram residues in/on cabbage and in the soil using HPLC-UV at 264 nm. A field test was conducted in December 2019 and 2020 to monitor isocycloseram dissipation in Jiangxi, China. Acetonitrile was used to extract isocycloseram from cabbage and soil. C18 and GCB were used to purify cabbage extracts, whereas soil extracts did not require purification. At the addition level of 0.01-1.0 mg/kg, the average recoveries in cabbage and soil were 91.81-109.95% and 89.89-104.08% respectively. After having applied 10% isocycloseram DC, isocycloseram dissipated faster in the cabbage matrix. Isocycloseram residues on cabbage leaves could be removed through simple cleaning methods, especially by soaking in 2% citric acid.


Asunto(s)
Brassica , Residuos de Plaguicidas , Contaminantes del Suelo , Cromatografía Líquida de Alta Presión , Semivida , Residuos de Plaguicidas/análisis , Suelo , Contaminantes del Suelo/análisis
2.
J Hazard Mater ; 421: 126757, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34352522

RESUMEN

Inhalation exposure and beryllium (Be) toxicity are well-known, but research on bioaccessibility from soils via different exposure pathways is limited. This study examined soils from a legacy radioactive waste disposal site using in vitro ingestion (Solubility Bioaccessibility Research Consortium [SBRC], physiologically based extraction test [PBET], in vitro gastrointestinal [IVG]), inhalation (simulated epithelial lung fluid [SELF]) and dynamic two-stage bioaccessibility (TBAc) methods, as well as 0.43 M HNO3 extraction. The results showed, 70 ±â€¯4.8%, 56 ±â€¯16.8% and 58 ±â€¯5.7% of total Be were extracted (gastric phase [GP] + intestinal phase [IP]) in the SBRC, PBET, and IVG methods, respectively. Similar bioaccessibility of Be (~18%) in PBET-IP and SELF was due to chelating agents in the extractant. Moreover, TBAc-IP showed higher extraction (20.8 ±â€¯2.0%) in comparison with the single-phase (SBRC-IP) result (4.8 ±â€¯0.23%), suggesting increased Be bioaccessibility and toxicity in the gastrointestinal tract when the contamination derives from the inhalation route. The results suggested Be bioaccessibility depends on solution pH; time of extraction; soil reactive fractions (organic-inorganic); particle size, and the presence of chelating agents in the fluid. This study has significance for understanding Be bioaccessibility via different exposure routes and the application of risk-based management of Be-contaminated sites.


Asunto(s)
Arsénico , Contaminantes del Suelo , Arsénico/análisis , Berilio/toxicidad , Disponibilidad Biológica , Contaminación Ambiental , Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
3.
J Hazard Mater ; 421: 126756, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34352523

RESUMEN

Widespread heavy metal pollution in soils has posed serious threat to vegetable production and food security, yet little is still known about heavy metal accumulation and distribution in the majority of vegetable crops. Here, we report the generation of a tissue atlas of cadmium accumulation in zucchini (Cucurbita pepo var. Giromontial), a globally important cucurbit crop, based on two-season experiment with six genotypes grown under cadmium contaminated soils. Plant growth and development as manifested by biomass, flowering time and plant architecture were unaffected by 10 mg/kg cadmium treatment, but high level of cadmium enrichment was detected in all genotypes. Roots accumulated the largest amount of cadmium, whereas the cadmium concentrations in fruits was also considerable. The exocarps of fruits possessed nearly half of the total cadmium in fruits, rendering it a "hotspot" of safety risk. Measurement of the thiol-containing chelates revealed that concentration of GSH but not PCs was correlated with the cadmium concentration in subdivided fruit tissues, suggesting a mechanism of phloem-specific transportation of cadmium in the form of Cd-GSH. Based on the collective data, a tentative model describing the relationship between long-distance phloem transport and cadmium distribution in sink organs is proposed. The implications for food safety are discussed.


Asunto(s)
Cadmio , Contaminantes del Suelo , Cadmio/análisis , Inocuidad de los Alimentos , Raíces de Plantas/química , Contaminantes del Suelo/análisis , Compuestos de Sulfhidrilo , Verduras
4.
Sci Total Environ ; 802: 149729, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34454135

RESUMEN

Atmospheric heavy metal deposition in agroecosystems has increased recently, especially in northern China, which poses serious risks to crop safety and human health via food chain. Wheat grains can accumulate high levels of Pb even when wheat is planted in soils with low levels of Pb. However, the influence of atmospheric deposition on the accumulation and distribution of Pb in wheat grain is still unclear. A field survey was conducted in three districts (A: a district with industrial and traffic pollution; B: a district with traffic pollution; and C: an unpolluted district) in Hebei Province, North China. The grain of wheat cultivated in district A accumulated more Pb from soil and atmospheric deposition than those in other districts, and the bran from district A contained 3.50 and 2.04 times more Pb than those from districts B and C, respectively. The Pb distribution pattern in wheat grain detected by laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was characterized by accumulation mostly in the pericarp and seed coat rather than in the crease, embryo and endosperm. Furthermore, Pb isotopic data showed that airborne Pb was the major source (>50%) of Pb in wheat grain. Interestingly, average contributions of Pb from atmospheric deposition to white flour (78.22%) were higher than its contributions to bran (56.27%). In addition, wheat flag leaves were exposed to PbSO4 at the booting stage, and much greater Pb accumulation (0.33-0.48 mg/kg) was observed in exposed wheat grain than in the control (P < 0.05), PbSO4 constituted most (82.80-100%) of the Pb in the wheat grain. In summary, the results confirmed the efficient foliar Pb uptake and transfer from atmospheric deposition into wheat grain. It would be a new sight for understanding the contribution of airborne Pb to Pb accumulation in wheat grains.


Asunto(s)
Terapia por Láser , Metales Pesados , Contaminantes del Suelo , China , Grano Comestible/química , Monitoreo del Ambiente , Humanos , Plomo , Espectrometría de Masas , Suelo , Contaminantes del Suelo/análisis , Triticum
5.
Sci Total Environ ; 802: 149865, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34455271

RESUMEN

The heavy metal accumulation in the Tibet Plateau (TP) poses a serious ecologic risk to the health of human and the other biota. Given the TP far away from the large anthropogenic emission sources, the rapid development of traffic activities during last several decades possibly leads to the elevated heavy metal concentration in the roadside soils. Therefore, we comprehensively assessed the heavy metal distribution in the 0-5 cm and 15-20 cm depth soils located at 5 m, 50 m, and 100 m distance to the edge of two major roads among the different vegetation covers and climatic conditions in the TP to verify this hypothesis. Results show that most of heavy metal concentrations in soils of different distance to the major road display an insignificant difference. The Nemero Synthesis indexes which represent the risk of pollution for these regions almost range 1 to 2 (low pollution risk), except 12.7 (extreme pollution risk) at one site. These indicate the limited impacts from the traffic activities for the whole region, but at some specific sites with the elevated traffic pollution. The forest cover at the altitude of 3700-4100 m has the highest mercury accumulation due to the vegetation and climatic factors induced the higher atmospheric depositions and stronger complexation with the organic matters. The statistical analysis finally suggests the geogenic weathering processes, climate, terrain and vegetation play an important role in shaping heavy metal distribution along the roadside of the TP.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Monitoreo del Ambiente , Humanos , Metales Pesados/análisis , Suelo , Contaminantes del Suelo/análisis , Tibet , Emisiones de Vehículos/análisis
6.
Sci Total Environ ; 802: 149839, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34455276

RESUMEN

Elevated human exposure to metals and metalloids (metal(loid)s) may lead to acute sickness and pose a severe threat to human health. The human body is exposed to metal(loid)s principally through food, water, supplements, and (occasionally) air. There are inherent background levels of many metal(loid)s in regional soils as a consequence of geological sources. Baseline levels coupled with anthropogenic sources such as regional application of biosolids may lead to increased levels of certain metal(loid)s in soil, leading to potential transfer to water sources and potential uptake by plants. The latter could potentially transfer into the feed-to-food chain, viz. grazing animals, and bio-transfer to food products resulting in human exposure. This study addresses health concerns due to excessive intake of metal(loid)s by conducting a traditional review of peer-reviewed journals between 2015 and 2019, secondary references and relevant websites. The review identified the most researched metal(loid)s as Cu, Zn, Pb, Cd, Ni, Cr, As, Hg, Mn, Fe in the environment. The potential uptake of metal(loid)s by plants (phytoavailability) is a function of the mobility/retainability of metal(loid)s in the soil, influenced by soil geochemistry. The most critical parameters (including soil pH, soil organic matter, clay content, cation exchange capacity, the capability of decomposition of organic matter by microbes, redox potential, ionic strength) influencing metal(loid)s in soil are reviewed and used as a foundation to build a framework model for ranking metal(loid)s of concern. A robust quantitative risk assessment model is recommended for evaluating risk from individual metal(loid)s based on health-based indices (Daily Dietary Index (DDI), No Observed Adverse Effect Level (NOAEL), and Lowest Observed Adverse Effect Level (LOAEL)). This research proposes a risk assessment framework for potentially harmful metal(loid)s in the environment and highlights where regulation and intervention may be required.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Monitoreo del Ambiente , Humanos , Irlanda , Metales Pesados/análisis , Factores de Riesgo , Contaminantes del Suelo/análisis
7.
Sci Total Environ ; 802: 149861, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34461475

RESUMEN

Biochar has been widely advocated due to its special properties and sustainability for agriculture soil amendment. The influencing mechanism of biochar on soil properties is a key aspect of quantifying and predicting its benefits and trade-offs. The contribution of biochar to both environmental and agricultural benefits has been deeply discussed and extensively reviewed, but few reviews have focused on modeling biochar effects. An overview of recent advances in biochar modeling is illustrated and approaches classified in this paper. Applications of a machine learning model, a deterministic model, and a numerical model to biochar are categorized and summarized. A discussion of the advantages and disadvantages of each model and a comparison among them are also provided. Finally, this paper gives many suggestions on narrowing the knowledge gap to advance biochar modeling. Further study of biochar modeling in management planning and design and application of the model results in agricultural systems will help accelerate the expansion of biochar's application scale and encourage the efficient utilization of waste in agricultural systems.


Asunto(s)
Carbón Orgánico , Contaminantes del Suelo , Agricultura , Suelo , Contaminantes del Suelo/análisis
8.
Sci Total Environ ; 802: 149788, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34461479

RESUMEN

In Mexico, millions of tons of mining wastes are deposited in the open pit. Their content in potentially toxic elements (PTE) represents an environmental risk. In the tailings, pioneer plant communities are established, associated with a determined diversity of fungi; plants, and fungi are fundamental in the natural rehabilitation of mining wastes. The objective was to evaluate the impact of the natural establishment of two plant species on the microbial activity, on the composition of the fungal community, and on the mitigation of the effect of PTE in a contaminated mine tailing. In a tailing, we selected three sites: one non-vegetated; one vegetated by Reseda luteola, and one vegetated by Asphodelus fistulosus. In the substrates, we conducted a physical and chemical characterization; we evaluated the enzymatic activity, the mineralization of the carbon, and the concentration of PTE. We also determined the fungal diversity in the substrates and in the interior of the roots, and estimated the accumulation of carbon, nitrogen, phosphorus and PTE in plant tissues. The tailings had a high percentage of sand; the non-vegetated site presented the highest electric conductivity, and the plant cover reduced the concentration of PTE in the substrates. Plants increased the carbon content in tailings. The enzymatic activities of ß-glucosidase and dehydrogenase, and the mineralization of carbon were highest at the site vegetated with A. fistulosus. Both plant species accumulated PTE in their tissues and exhibited potential in the phytoremediation of lead (Pb), cadmium (Cd), and copper (Cu). Fungal diversity was more elevated at the vegetated sites than in the bare substrate. Ascomycota prevailed in the substrates; the substrates and the plants shared some fungal taxa, but other taxa were specific. The plant coverage and the rhizosphere promoted the natural attenuation and a rehabilitation of the extreme conditions of the mining wastes, modulated by the plant species.


Asunto(s)
Metales Pesados , Micobioma , Contaminantes del Suelo , Metales Pesados/análisis , Minería , Plantas , Rizosfera , Suelo , Contaminantes del Suelo/análisis
9.
Sci Total Environ ; 802: 149796, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34464787

RESUMEN

Elevated arsenic (As) in soil is of public concern due to the carcinogenicity. Phosphorus (P) strongly influences the adsorption, absorption, transport, and transformation of As in the soil and in organisms due to the similarity of the chemical properties of P and As. In soil, P, particularly inorganic P, can release soil-retained As (mostly arsenate) by competing for adsorption sites. In plant and microbial systems, P usually reduces As (mainly arsenate) uptake and affects As biotransformation by competing for As transporters. The intensity and pattern of PAs interaction are highly dependent on the forms of As and P, and strongly influenced by various biotic and abiotic factors. An understanding of the PAs interaction in 'soil-plant-microbe' systems is of great value to prevent soil As from entering the human food chain. Here, we review PAs interactions and the main influential factors in soil, plant, and microbial subsystems and their effects on the As release, absorption, transformation, and transport in the 'soil-plant-microbe' system. We also analyze the application potential of P fertilization as a control for As pollution and suggest the research directions that need to be followed in the future.


Asunto(s)
Arsénico , Contaminantes del Suelo , Arseniatos/análisis , Arsénico/análisis , Contaminación Ambiental , Humanos , Fósforo , Plantas , Suelo , Contaminantes del Suelo/análisis
10.
Sci Total Environ ; 802: 149899, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34464792

RESUMEN

A mass of tailings left by mineral exploitation have caused serious environmental pollution. Although many studies have shown that soil microorganisms have the potential to remediate environmental pollution, the interaction mechanism between microorganisms and the surrounding environment of tailings is still unclear. In this study, 15 samples around pyrite mine tailing were collected to explore the ecological effects of environmental factors on bacterial community. The results showed that most of the samples were acidic and contaminated by multiple metals. Cadmium (Cd), copper (Cu), nickel (Ni) migrated and accumulated to into downstream farmlands while chromium (Cr) was the opposite. Proteobacteria, Chloroflex and Actinobacteria were the dominant phyla. Soil pH, total phosphorus (TP), total nitrogen (TN), available potassium (AK), available phosphorus (AP), the bacteria abundance and diversity all gradually increased with the increase of the distance from the tailing. Invertase, acid phosphatase, total organic carbon (TOC), pH, TP and Cr were the main influencing factors to cause the variation of bacterial community. This work could help us to further understand the changes in soil microbial communities around pollution sources.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , China , Monitoreo del Ambiente , Contaminación Ambiental , Metales Pesados/análisis , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
11.
Sci Total Environ ; 802: 149802, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34464799

RESUMEN

Corncob powder possessing its superiority in environmental sustainability and cost, was approved with strong capability of being a replacement of biochar in facilitating the microbial carbonate precipitation process. In this study, the ureolytic bacterial strain Bacillus sp. WA isolated from a pre-acquired metal contaminated soil in Guiyu, China, was showed to be well attached on the surfaces of corncob powder, indicating the carrier's role as a durable shelter for bacterial cells. The efficient immobilization helped develop biochemical composite material (BCM) and proven to function better the calcite precipitation. Afterwards, the mechanism and multi-directional benefits of BCM in edaphic cadmium remediation were examined through pot experiment and compared with corncob powder/bacterial strain/nutrient media as control groups. Integrated lab-scale analyses emphasized the advantages of BCM by the maximum soil urease activity (up to 3.440 U/mg and increased by 214% in 28 days), maximal bacterial propagation (most abundant population in fluorescence microscopy), richest surface functional group (most remarkable OC bond and CO bond in FTIR result), notable calcite precipitation (clear calcite crystals on the surface of BCM compared to control group under SEM-EDS), and highest Cd immobilization rate (exchangeable Cd decreased by 68.54%), among all treatments. The pH and electroconductivity measurements additionally led to the mechanism of corncob powder and NBU promoting pre-existed ureolytic bacteria in soil, which demonstrated the added value of corncob to be fine carbon source and residence shelter for soil microorganism, revealing its potential in developing agricultural materials.


Asunto(s)
Contaminantes del Suelo , Suelo , Bacterias , Cadmio/análisis , Polvos , Contaminantes del Suelo/análisis , Zea mays
12.
Chemosphere ; 286(Pt 1): 131583, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34293558

RESUMEN

Chemical degradation is one of the crucial methods for the remediation of hydrophobic organic compounds (HOCs) in soil/sediment. The sequestration effect of black carbon (BC) can affect the adsorption state of HOCs, thereby affecting their chemical degradability. Our study focused on the chemical degradability of 2-Chlorobiphenyl (PCB1) sequestrated on the typical BC (fly ash (FC), soot (SC), low-temperature biochar (BC400) and high-temperature biochar (BC900)) by iron-nickel bimetallic nanomaterials (nZVI/Ni) based on TENAX desorption technology. The results showed that PCB1 adsorbed in various states were simultaneously dechlorinated by nZVI/Ni. Specifically, rapid-desorption-state PCB1 tended to degrade more easily than resistant-desorption-state PCB1. Moreover, the degradation mechanism varied according to the type of BC. In the case of FC and SC, the degradation rate was lower than the desorption rate for the PCB1 in rapid and slow desorption states, and the degradation rate of PCB1 in the resistant desorption state was negligible. The PCB1 on FC and SC was first desorbed from BC and then degraded. However, in terms of BC400 and BC900, the degradation rate was higher than the desorption rate, and the degradation rate of the resistant-desorption-state PCB1 was 1.4 × 10-2 h-1 and 4.1 × 10-2 h-1, respectively. The graphitized structure of BC900 can directly transfer electrons, so more than 90% of the resistant-desorption-state PCB1 could be degraded. In addition, BC may affect the longevity of nZVI/Ni, thereby affecting its degradability. Therefore, the chemical degradability of BC-adsorbed HOCs should be comprehensively evaluated based on the adsorption state and the properties of BC.


Asunto(s)
Contaminantes del Suelo , Hollín , Adsorción , Carbón Orgánico , Suelo , Contaminantes del Suelo/análisis , Tecnología
13.
Chemosphere ; 286(Pt 1): 131570, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34293559

RESUMEN

The increase in pollution increased the threat level of living organisms in the environment. Municipal Solid Waste is one of the most important wastes which contribute to polluted sites affecting livelihood. They pollute the water stream, marine environment ecology, soil fertility, and agriculture production. This, in turn, reduces the microflora of the marine environment, agricultural soil, and fertility. This could be analyzed by setting up a Winogradsky column using dumpsite soil samples. The current work was designed to study the municipal solid wastes from different dumpsite soil. Soil characterization revealed that the pH of Kodungaiyur and Otteri was 7.3 and 6.4. The bulk density was 0.067 g/cm3 and 0.069 g/cm3. The Porosity resulted to be 0.511 particle/volume and 0.513 particle/volume for Kodungaiyur and Otteri. The Kodungaiyur soil containing contaminants supplied with natural sources showed a 100% germination index, and Otteri soil containing contaminants supplied with natural sources showed a maximum vigour index. The presence of medicinal strips in the collected soil samples led to the study on Acetaminophen degradation. HB1 showed to be 79 ± 0.005% at optimum pH 5 containing 100 mg/L of Acetaminophen at day four among the isolated bacterial strains. Further, the intermediate formation was determined using FTIR and GC-MS. The isolated HB1 bacterial strain was identified as Staphylococcus hominis, which is heterotroph.


Asunto(s)
Contaminantes del Suelo , Suelo , Acetaminofén/toxicidad , Agricultura , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Residuos Sólidos/análisis
14.
Chemosphere ; 286(Pt 1): 131595, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34293572

RESUMEN

Because of the high hydrophobicity, low volatility, and high sorption capacity of PAHs, their remediation in contaminated soil is challenging. Electrokinetic (EK) enhanced chemical remediation is an emerging dual technology employed in this study, using a new oxidant peroxymonosulfate (PMS) to remediate PAHs contaminated soil. Here, PMS migration under electric field and the remediation efficiency for the PAHs polluted soil were assessed. We observed that the PMS removal efficiencies (59.7%-82.8%) were higher than those with persulfate (PS) (53.9%-78.5%), indicating PMS's superior oxidation capacity for PAHs. Although oxidant PMS can decontaminate PAHs in polluted soils, its removal of PAHs was only 11.0% without the enhanced methods. The enhancements increased the removal efficiency for PAHs from 0.33 to 2.10 times. At fixed catholyte pH of 4, the highest removal efficiency (34.1%) was achieved because it enhanced PMS migration from cathode to anode. These findings suggested that PMS was a potential oxidant for EK remediation, and some enhancements must be applied in EK combined PMS remediation PAHs polluted soil.


Asunto(s)
Restauración y Remediación Ambiental , Contaminantes del Suelo , Peróxidos , Suelo , Contaminantes del Suelo/análisis
15.
Chemosphere ; 286(Pt 1): 131638, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34303908

RESUMEN

Soil samples were collected from a representative arsenic (As) contaminated region under phytoremediation of hyperaccumulation plants. Relative abundance and diversity of microbial communities in the soil samples were characterized via 16S rRNA genes sequencing. At the phylum level, Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Firmicutes shows the highest abundance, accounting for more than 90 % of the classified sequences in the soil samples. Physicochemical parameters including pH, total organic carbon (TOC), cation exchange capacity (CEC), and electrical conductivity (EC), and heavy metal concentrations including total and bioaccessible contents in the soil samples were determined to investigate potential relationships between the microbial communities and the environmental factors. Principal component analysis (PCA) based on the operational taxonomic units (OTUs) matrix revealed distinct separation among the samples. The soil pH was confirmed as the dominant force to discriminate the soil samples with similar land use type and heavy metal contamination. There was little relevance between the total concentrations of heavy metals and the microbial communities. However, the bioaccessible concentrations of heavy metals were associated with the physicochemical parameters and relative abundances of bacterial genera according to correlation analyses. Although the soil samples were considerably contaminated by As, the abundances of bacterial phyla linked with As were lower than 1.0 % in most of the soil samples. The results indicated that the abundances of microbial communities in the soils were the consequence of concerted effects from all the environmental factors.


Asunto(s)
Metales Pesados , Microbiota , Contaminantes del Suelo , Arsenicales , Metales Pesados/análisis , ARN Ribosómico 16S/genética , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisis , Sulfuros
16.
Chemosphere ; 286(Pt 1): 131470, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34311401

RESUMEN

Heavy metals in the soil are major global environmental problems. Waste cotton was used to synthesize a novel ß-CD/hydrothermal biochar (KCB), which is a low-cost and environment-friendly adsorbent for heavy metal soil remediation. KCB were used as reactive materials of electrokinetic-permeable reactive barrier (EK-PRB) to explore the removal characteristics of heavy metals. FTIR and XPS analysis revealed that KCB contained large numbers of surface functional groups. Adsorption of KCB for Pb2+ and Cd2+ reached 50.44 mg g-1 and 33.77 mg g-1, respectively. Metal ions in contaminated soil were removed by reactive barrier through electromigration, electrodialysis and electrophoresis, the removal efficiency of Pb2+ and Cd2+ in soil reached 92.87% and 86.19%. This finding proves that KCB/EK-PRB can be used as a cheap and green process to effectively remediate soils contaminated with heavy metals.


Asunto(s)
Restauración y Remediación Ambiental , Metales Pesados , Contaminantes del Suelo , Carbón Orgánico , Metales Pesados/análisis , Suelo , Contaminantes del Suelo/análisis
17.
Chemosphere ; 286(Pt 1): 131556, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34311403

RESUMEN

In October 2019, a fire occurred in a tire-recycling facility in Alytus (Lithuania), where around 5000 t of tires had been stored. Only after 10 days was the fire completely extinguished, and the potential contamination of the surrounding environment has raised a large public concern. With an aim to assess the pollution level and pollutants distribution in the surrounding area, we conducted a study on polycyclic aromatic hydrocarbons (PAHs) and heavy metals. High concentrations of total PAHs were found inside the fire zone (315-5872 ng g-1 dw), whereas those detected in the surrounding soils were significantly lower (1.9-72 ng g-1 dw). Some areas with higher anthropogenic impact were found to contain PAH concentrations as high as 70198 ng g-1 dw. Concentrations of Cr, Zn, Ni, Cu, Pb were in the range of 1.1-93.9; 20.7-227.5; 0.2-35.7; 0.9-21.3; 0.9-102.9 µg g-1, respectively. Zn was the prevailing metal in the fire zone, elevated concentrations of Cr, Ni and Cu were also detected in this area. Principal component analysis (PCA) revealed several locations affected by the fire. The one located the closest to the fire zone was found to be highly contaminated with the heavy metals, just like the whole fire zone. Increase of the carcinogenic risk was observed in the fire zone, but no significant risk was detected in the fire-affected stations. The highest carcinogenic risk was detected in the zones with high anthropogenic loading (traffic and urban activities).


Asunto(s)
Metales Pesados , Hidrocarburos Policíclicos Aromáticos , Contaminantes del Suelo , China , Monitoreo del Ambiente , Metales Pesados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Suelo , Contaminantes del Suelo/análisis
18.
Chemosphere ; 286(Pt 1): 131574, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34315072

RESUMEN

Thermal plasma blasting technology has been widely applied for rock cracking. Though, the application for environmental remediation has yet to be reported. Since the delivery of remediation agents into diesel contaminated clayey zones are exceptionally challenging, herein, this study explores the effect of pilot-scale thermal plasma blasting for soil fracturing and concurrently dispersing the Fenton reagent into the diesel contaminated silty soils. Six times plasma blasting with sole H2O2 at 20 kV had the highest degradation of diesel (>97%) with an equilibrium time of 3 h, and the final diesel concentration was below the South Korean regulated health standard (500 mg kg-1). This study highlights plasma blasting able to deliver H2O2 instantaneously and homogeneously into contaminated zone while promoting Fenton reaction synergism (fsyn: 2.04) between H2O2 and ≡Fe surface for effective remediation. Furthermore, the remediation cost (USD 4 metric ton-1) is much lower than most reported in situ technologies.


Asunto(s)
Restauración y Remediación Ambiental , Gases em Plasma , Contaminantes del Suelo , Arcilla , Peróxido de Hidrógeno , Suelo , Contaminantes del Suelo/análisis
19.
Chemosphere ; 286(Pt 1): 131660, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34315078

RESUMEN

Biochar mediated pollutant removal is gaining attention because of high efficiency of the process. However, effective recycling avenues of the pollutant-saturated biochars are scarce in the knowledge base; while such materials can be a new source of long-range contamination. Therefore, potential of vermitechnology for eco-friendly recycling of pollutant-loaded biochar was assessed by using arsenic-saturated native (NBC) and exfoliated (EBC) biochars as feedstocks for the first time. Interestingly, the bioavailable arsenic fractions (water soluble and exchangeable) considerably reduced by 22-44 % with concurrent increment (~8-15 %) of the recalcitrant (residual and organic bound) fractions in the biochar-based feedstocks. Consequently, ~2-3 folds removal of the total arsenic was achieved through vermicomposting. The earthworm population growth (2.5-3 folds) was also highly satisfactory in the biochar-based feedstocks. The results clearly imply that Eisenia fetida could compensate the arsenic-induced stress to microbial population and greatly augmented microbial biomass, respiration and enzyme activity by 3-12 folds. Moreover, biochar-induced alkalinity was significantly neutralized in the vermibeds, which remarkably balanced the TOC level and nutrient (N, P, and K) availability particularly in EBC + CD vermibeds. Overall, the nutrient recovery potential and arsenic removal efficiency of vermitechnology was clearly exhibited in NBC/EBC + CD (12.5:87.5) feedstocks. Hence, it is abundantly clear that vermitechnology can be a suitable option for eco-friendly recycling of pollutant-saturated sorbing agents, like biochars.


Asunto(s)
Arsénico , Contaminantes del Suelo , Carbón Orgánico , Nutrientes , Suelo , Contaminantes del Suelo/análisis
20.
Chemosphere ; 286(Pt 1): 131599, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34315084

RESUMEN

In this study, 11 low/uncontaminated (including Lufa 2.2) and 9 contaminated field soils with varying geophysical and physicochemical characteristics were evaluated for toxicities based on oxygen consumption of sulfur-oxidizing bacteria (SOB). Oxygen consumption of the low/uncontaminated soils ranged between 7.9 mL and 9.5 mL, while contaminated soils ranged between 0.4 mL and 5.4 mL. Inherent test variability (CVi), variation due to soil natural properties (CVns) and minimal detectable difference (MDD) values ranged 1.2%-3.9%, 3.5%-16.9%, and 2.1%-4.3%, respectively. The toxicity threshold of 20% was established for soil toxicity based maximal tolerable inhibition (MTI). All the contaminated soils were found to be toxic and showed inhibition between 42% and 100% above the 20% threshold value. Increased proportions of clay and slit enhanced the of inhibitory effect of contaminants on SOB by reducing the oxygen consumption. Current study provides a suitable method for the rapid toxicity assessment of contaminated field soils with the advantages of ease of handling and rapidity without employing elutriates and sophisticated equipments and tools.


Asunto(s)
Contaminantes del Suelo , Suelo , Bacterias , Bioensayo , Oxidación-Reducción , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad , Azufre/toxicidad
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