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1.
Environ Monit Assess ; 193(1): 49, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33415539

RESUMO

Heavy metal pollution in the environment has gained interest in the past few decades, as it has been found to accumulate in soil and water, as well as in the human body. Heavy metals present a serious health risk to humans when the concentration level and exposure time are increased. Although they have been extensively studied in the environment and food, little is known regarding their occurrence in the Kurdistan Region of northern Iraq. To fill this gap, we investigated the occurrence of some metals and heavy metals, namely aluminium (Al), barium (Ba), mercury (Hg), manganese (Mn), lead (Pb), vanadium (V) and zinc (Zn), in the blood of crude oil workers (40 men) who have worked in crude oil fields for at least 3 years-exposed group. In addition, a control group of 40 men was selected who have never worked or been close to crude oil fields. There is a significant correlation of metal concentrations between exposed and control groups, especially for Al, Ba, Hg, Mn and V (significant for all metals). Even though the correlation for Pb and Zn was weak, the concentrations were higher by 2-folds in the exposed group compared to the control group. Thus, the exposure caused an increase in the concentration of heavy metals by at least 1-fold in the blood of the exposed group compared to the control group. The environmental and ecotoxicological relevance of heavy metals in humans and the environment in areas with industrial activities have yet to be assessed.


Assuntos
Metais Pesados , Petróleo , Poluentes do Solo , China , Monitoramento Ambiental , Humanos , Iraque , Masculino , Metais Pesados/análise , Medição de Risco , Poluentes do Solo/análise
2.
Environ Monit Assess ; 192(Suppl 1): 813, 2021 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-33443644

RESUMO

Orthosulfamuron, a rice herbicide of the family pyrimidinyl sulfonylurea, causes ground water contamination for its moderate persistence and high water solubility. It may cause phytotoxicity and, thereby, affect the growth of succeeding crops. Keeping in view of the environmental safety, the interaction between orthosulfamuron and soil fungi was investigated. Ten different fungal species were found to survive in the soil containing orthosulfamuron at the level of 50 mg kg-1. However, based on the previous research reports, Aspergillus niger was selected for the degradation study on orthosulfamuron in the sterilized soil. It exhibited concentration-depended degradation rate for orthosulfamuron, where the rate decreased with the increasing concentration of the herbicide. The degradation pattern of the herbicide followed the first-order rate kinetics for each applied concentration. The structural elucidation of the five degradation products by liquid chromatography-mass spectroscopic analysis indicated that the fungal strain could degrade the herbicide through various biochemical processes. The major degradation of the herbicide took place through the hydrolytic cleavage of sulfonylurea bridge and cleavage of N (urea bridge)-C (pyrimidinyl ring) bond. The rate and degradation pattern of orthosulfamuron found in the present study strongly imply the presence of a recognition mechanism for the substrate and a consequent metabolic response system in the A. niger strain isolated from the agricultural soil.


Assuntos
Herbicidas , Oryza , Poluentes do Solo , Aspergillus niger , Biodegradação Ambiental , Monitoramento Ambiental , Solo , Microbiologia do Solo
3.
Environ Monit Assess ; 193(1): 20, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389235

RESUMO

Soil heavy metal (Cr, Cu, Zn, Pb, Cd, V, As) concentrations in different areas were analyzed to investigate the effects of different industrial activities on heavy metal pollution status, potential ecological risk, and human health risk in Panzhihua. Our results showed that Cu and V enrichment in soil was due to ore smelting. Soil Cr accumulation was related to coal ore mining. Soil Cd, Zn, As, and Pb enrichment was attributed to high-temperature coal combustion. Under the effect of industrial activities, soils were moderately contaminated with Cd, uncontaminated to moderately contaminated with As and Zn, and uncontaminated with Cr, Cu, V, and Pb. Soil heavy metal potential ecological risk was considerable, and non-carcinogenic risks and carcinogenic risks of soil heavy metals were acceptable for adults but unacceptable for children. Thermal power generation was the dominated industrial activity that influence the soil heavy metal concentrations and environmental risks in Panzhihua, which posed considerable potential ecological risks and unacceptable heavy metal non-carcinogenic risks and As carcinogenic risk to both adults and children. This study indicates that industrial activities have great effects on heavy metal pollution, ecological risks, and health risk, and more attention should be paid to the ecological risk and health risks brought by thermal power generation.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Criança , China , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Metais Pesados/toxicidade , Medição de Risco , Solo , Poluentes do Solo/análise
4.
Environ Monit Assess ; 193(2): 65, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33449210

RESUMO

In areca nut and husk, 14 elements (As, Ca, Cd, Cl, Co, Cu, K, Mg, Mn, Na, Rb, Sb, and Zn) were determined, while 34 elements including rare earth elements were detected in the corresponding soil samples using instrumental neutron activation analysis and atomic absorption spectrometry methods, whereas the concentration levels of Hg in tested samples are negligible, perhaps, below the detection limits. No rare earth elements were detected in edible areca nut. The concentration levels of various essential elements and heavy elements such as As, Cd, and Cu present in areca nut are within the permissible levels, whereas Pb content is relatively higher than FAO/WHO's permissible levels. The order of bioaccumulation index for heavy metals in areca nut was Cd > Sb > Cu > Zn ≥ Mn ≥ Co > Pb ≥ As. Bioaccumulation index values are indicating that areca palm may not be able to accumulate other heavy elements in the edible areca nut, except for Cd. On the basis of pollution indices, Northeast Indian soil may be relatively unpolluted.


Assuntos
Metais Pesados , Poluentes do Solo , Oligoelementos , Areca , Monitoramento Ambiental , Índia , Metais Pesados/análise , Nozes/química , Solo , Poluentes do Solo/análise , Oligoelementos/análise
5.
Ecotoxicol Environ Saf ; 208: 111750, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396075

RESUMO

Contamination of agricultural land and water by heavy metals due to rapid industrialization and urbanization including various natural processes have become one of the major constraints to crop growth and productivity. Several studies have reported that to counteract heavy metal stress, plants should be able to maneuver various physiological, biochemical and molecular processes to improve their growth and development under heavy metal stress. With the advent of modern biotechnological tools and techniques it is now possible to tailor legume and other plants overexpressing stress-induced genes, transcription factors, proteins, and metabolites that are directly involved in heavy metal stress tolerance. This review provides an in-depth overview of various biotechnological approaches and/or strategies that can be used for enhancing detoxification of the heavy metals by stimulating phytoremediation processes. Synthetic biology tools involved in the engineering of legume and other crop plants against heavy metal stress tolerance are also discussed herewith some pioneering examples where synthetic biology tools that have been used to modify plants for specific traits. Also, CRISPR based genetic engineering of plants, including their role in modulating the expression of several genes/ transcription factors in the improvement of abiotic stress tolerance and phytoremediation ability using knockdown and knockout strategies has also been critically discussed.


Assuntos
Produtos Agrícolas/fisiologia , Fabaceae/fisiologia , Metais Pesados/toxicidade , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Biotecnologia , Produtos Agrícolas/metabolismo , Fabaceae/metabolismo , Metais Pesados/análise , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Estresse Fisiológico , Verduras/metabolismo
6.
Ecotoxicol Environ Saf ; 208: 111751, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396076

RESUMO

Lanmuchang mercury-thallium mine, a typical polymetallic mine is located in southwestern Guizhou, China, is the most serious and typical area resulted from multi-metal contamination (Tl, Hg, As, and Sb). After the mercury-thallium mining, a large area of surrounding rocks such as argillaceous sandstone with high contents of Tl, Hg, As, and Sb is exposed to air. Weathering caused the argillaceous sandstone to form different weathering layers, including the grey-black external layer, the brown-yellow middle layer and the gray-white inner layer, and the external layer was enriched with higher heavy metals. However, the reason of heavy metal migration and transformation in argillaceous sandstone caused by weathering is unclear. The objective of this paper was to investigate the migration, transformation and release characteristics of Tl, Hg, As, and Sb in argillaceous sandstone during the weathering. The results indicated that weathering not only promoted an acidic oxidation environment in argillaceous sandstone, but also increased its specific surface area, pore volume and hydrophilicity, which are beneficial to the permeability of oxygen and etching liquids during the process of weathering and leaching. Meanwhile, weathering led to the transformation or decomposition of hydrophilic groups, such as -OH and -CË­O in the grey-black external layer of argillaceous sandstone, resulting in the further release of heavy metals bound to these groups. The concentration of Tl, Hg, As, and Sb in the leaching solution of argillaceous sandstone represented a positive correlation with that of Fe, Ca, Mg at different levels, indicating that Tl, Hg, As, and Sb were released with the dissolution of Fe, Ca and Mg during weathering and leaching. In summary, these results indicated that weathering caused the dissolution and migration of heavy metals in the argillaceous sandstone. Tl, Hg, As, and Sb migrated from the grey-white inner layer to the grey-black external layer and partially adsorbed by free alumina (Ald), jarosite and Ca-bearing minerals, showing enrichment phenomena, partially released into the environment, causing environmental pollution.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , China , Compostos Férricos , Mercúrio/análise , Sulfatos , Tálio/análise
7.
Ecotoxicol Environ Saf ; 208: 111756, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396079

RESUMO

To deeply assess the feasibility of sewage sludge-based biochars for use in soil applications, this review compared sewage sludge-based biochars (SSBBs) with lignocellulose-based biochars (LCBBs) in terms of their pyrolysis processes, various fractions and potential soil applications. Based on the reviewed literature, significant differences between the components of SSBB and LCBB result in different pyrolysis behavior. In terms of the fractions of biochars, obvious differences were confirmed to exist in the carbon content, surface functional groups, types of ash fractions and contents of potential toxic elements (PTEs). However, a clear influence of the feedstock on labile carbon and polycyclic aromatic hydrocarbons (PAHs) was not observed in the current research. These differences determined subsequent discrepancies in the soil application potential and corresponding mechanisms. The major challenges facing biochar application in soils and corresponding recommendations for future research were also addressed. LCBBs promote carbon sequestration, heavy metal retention and organic matter immobilization. The application of SSBBs is a promising approach to improve soil phosphorus fertility, immobilize heavy metals and provide available carbon sources for soil microbes to stimulate microbial biomass. The present review provides guidance information for selecting appropriate types of biochars to address targeted soil issues.


Assuntos
Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Metais Pesados/química , Pirólise , Poluentes do Solo/química , Biomassa , Carbono , Lignina , Metais Pesados/análise , Hidrocarbonetos Policíclicos Aromáticos , Esgotos , Solo , Poluentes do Solo/análise
8.
Ecotoxicol Environ Saf ; 208: 111757, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396080

RESUMO

A pot study was performed to assess the phytoremedial potential of Cymbopogon citratus (D.C.) Staf. for reclamation of coal mine overburden dump wastes, emphasizing the outcome of amendment practices using cow dung manure (CM) and garden soil mixtures on the revegetation of over-burden wastes (OB). Wastes amendment with cow dung manure and garden soil resulted in a significant increase in soil health and nutrient status along with an increment in the phytoavailability of Zn and Cu which are usually considered as micronutrients, essential for plant growth. A significant increment in the total biomass of lemongrass by 38.6% under CM20 (OB: CM 80:20) was observed along with improved growth parameters under amended treatments as compared to OB (100% waste). Furthermore, the proportionate increases in the assimilative rate, water use efficiency, and chlorophyll fluorescence have been observed with the manure application rates. Lemongrass emerged out to be an efficient metal-tolerant herb species owing to its high metal-tolerance index (>100%). Additionally, lemongrass efficiently phytostablized Pb and Ni in the roots. Based on the strong plant performances, the present study highly encourages the cultivation of lemongrass in coal mining dumpsites for phytostabilization coupled with cow-dung manure application (20% w/w).


Assuntos
Biodegradação Ambiental , Cymbopogon/fisiologia , Esterco , Poluentes do Solo/metabolismo , Animais , Biomassa , Bovinos , Carvão Mineral , Minas de Carvão , Cymbopogon/crescimento & desenvolvimento , Metais , Desenvolvimento Vegetal , Raízes de Plantas/química , Plantas , Solo , Poluentes do Solo/análise
9.
Ecotoxicol Environ Saf ; 208: 111758, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396081

RESUMO

The cultivation of leafy vegetables on metal contaminated soil embodies a serious threat to yield and quality. In the present study, the potential role of exogenous jasmonic acid (JA; 0, 5, 10, and 20 µM) on mitigating chromium toxicity (Cr; 0, 150, and 300 µM) was investigated in choysum (Brassica parachinensis L.). With exposure to increasing Cr stress levels, a dose-dependent decline in growth, photosynthesis, and physio-biochemical attributes of choysum plants was observed. An increase in Cr levels also resulted in oxidative stress closely associated with higher lipoxygenase activity (LOX), hydrogen peroxide (H2O2) generation, lipid peroxidation (MDA), and methylglyoxal (MG) levels. Exogenous application of JA alleviated the Cr-induced phytotoxic effects on photosynthetic pigments, gas exchange parameters, and restored growth of choysum plants. While exposed to Cr stress, JA supplementation induced plant defense system via enhanced regulation of antioxidant enzymes, ascorbate and glutathione pool, and the glyoxalase system enzymes. The coordinated regulation of antioxidant and glyoxalase systems expressively suppressed the oxidative and carbonyl stress at both Cr stress levels. More importantly, JA restored the mineral nutrient contents, restricted Cr uptake, and accumulation in roots and shoots of choysum plants when compared to the only Cr-stressed plants. Overall, the application of JA2 treatment (10 µM JA) was more effective and counteracted the detrimental effects of 150 µM Cr stress by restoring the growth and physio-biochemical attributes to the level of control plants, while partially mitigated the detrimental effects of 300 µM Cr stress. Hence, JA application might be considered as an effective approach for minimizing Cr uptake and its detrimental effects in choysum plants grown on contaminated soils.


Assuntos
Antioxidantes/farmacologia , Brassica/fisiologia , Cromo/toxicidade , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Brassica/efeitos dos fármacos , Brassica/metabolismo , Glutationa/metabolismo , Peróxido de Hidrogênio/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo
10.
Ecotoxicol Environ Saf ; 208: 111769, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396087

RESUMO

Soils contaminated with heavy metals such as Chromium (Cr) and Cadmium (Cd) severely impede plant growth. Several rhizospheric microorganisms support plant growth under heavy metal stress. In this study, Cr and Cd stress was applied to in vitro germinating seedlings of a Legume plant species, Sesbania sesban, and investigated the plant growth potential in presence and absence of Bacillus anthracis PM21 bacterial strain under heavy metal stress. The seedlings were exposed to different concentrations of Cr (25-75 mg/L) and Cd (100-200 mg/L) in Petri plates. Growth curve analysis of B. anthracis PM21 revealed its potential to adapt Cr and Cd stress. The bacteria supported plant growth by exhibiting ACC-deaminase activity (1.57-1.75 µM of α-ketobutyrate/h/mg protein), producing Indole-3-acetic acid (99-119 µM/mL) and exopolysaccharides (2.74-2.98 mg/mL), under heavy metal stress condition. Analysis of variance revealed significant differences in growth parameters between the seedlings with and without bacterial inoculation in metal stress condition. The combined Cr+Cd stress (75 + 200 mg/L) significantly reduced root length (70%), shoot length (24%), dry weight (54%) and fresh weight (57%) as compared to control. Conversely, B. anthracis PM21 inoculation to seedlings significantly increased (p ≤ 0.05) seed germination percentage (5%), root length (31%), shoot length (23%) and photosynthetic pigments (Chlorophyll a: 20%; Chlorophyll b: 16% and total chlorophyll: 18%), as compared to control seedlings without B. anthracis PM21 inoculation. The B. anthracis PM21 inoculation also enhanced activities of antioxidant enzymes, including superoxide dismutase (52%), peroxidase (66%), and catalase (21%), and decreased proline content (56%), electrolyte leakage (50%), and malondialdehyde concentration (46%) in seedlings. The B. anthracis PM21 inoculated seedlings of S. sesban exhibited significantly high (p ≤ 0.05) tissue deposition of Cr (17%) and Cd (16%) as compared to their control counterparts. Findings of the study suggested that B. anthracis PM21 endured metal stress through homeostasis of antioxidant activities, and positively impacted S. sesban growth and biomass. Further experiments in controlled conditions are necessary for investigating phytoremediation potential of S. sesban in metal-contaminated soils in presence of B. anthracis PM21 bacterial strain.


Assuntos
Bacillus anthracis/fisiologia , Metais Pesados/toxicidade , Sesbania/fisiologia , Poluentes do Solo/toxicidade , Bacillus anthracis/metabolismo , Biodegradação Ambiental , Cádmio/metabolismo , Catalase/metabolismo , Clorofila , Clorofila A/metabolismo , Cromo/análise , Germinação/efeitos dos fármacos , Ácidos Indolacéticos , Metais Pesados/análise , Plântula/metabolismo , Sesbania/metabolismo , Sesbania/microbiologia , Solo , Poluentes do Solo/análise
11.
Ecotoxicol Environ Saf ; 208: 111770, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396088

RESUMO

Toxicity of perfluoroalkyl substances (PFASs) in soils towards bacteria shows an impact on its ecosystem function. This study aims to obtain insight into the effect of hydrolase (e.g. α-amylase) in soil on metabolism adaptions of bacteria (e.g. Bacillus substilis) against PFOS exposure. Results show that exogenous α-amylase alleviates PFOS toxicity to bacteria growth, disturbance to membrane permeability and stimulation to reactive oxygen species (ROS) production. The mechanisms were owing to that α-amylase strongly influences the strategies of metabolism adaptions of bacteria against PFOS stress. In details, α-amylase prompts bacteria to regulate the secretion of extracellular polymeric substances (EPSs) and the production of metabolic signal (acetic acid), which leads to changes in the physicochemical properties (hydrophilicity, surface charge) of the bacterial surface and the inactivation of the interaction with PFOS, thereby reducing the PFOS toxicity. Molecular simulations show that PFOS combines with Srt A at Gly 53 and Trp 171, which may induce the increase of permeability and changes of surface characteristics. Meanwhile, α-amylase competes with Srt A to bind PFOS at Arg 125 and Lys 176. This competition changes the physicochemical characteristics of PFOS and its bioavailability, further improving the metabolism adaptions of bacteria against PFOS. Altogether, this work provides direct evidences about α-amylase buffering effect of PFOS and demonstrates that the presence of α-amylase affects the essential but complex metabolic response in bacteria triggered by PFOS.


Assuntos
Fluorcarbonetos/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , alfa-Amilases/fisiologia , Ácidos Alcanossulfônicos/toxicidade , Bactérias , Ecossistema , Poluentes do Solo/análise
12.
Ecotoxicol Environ Saf ; 208: 111582, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396105

RESUMO

In recent years, heavy metal pollution has caused immeasurable harm to the environment. As an emerging technology, phytoremediation technology has gained a place in the treatment of heavy metal pollution with its unique advantages. This study analyzes the toxic effects of mulberry (Morus alba) seeds, seedling growth and silkworm under heavy metal stress of lead (Pb) and cadmium (Cd), and explore the accumulation and migration of Pb and Cd in the soil-mulberry tree-silkworm system. The main results were as follows: (1) Seed germination and potted seedling experiments were conducted under heavy metal Pb and Cd stresses, and it was found that Pb and Cd had inhibitory effects on mulberry seed germination, growth and photosynthesis of mulberry seedlings, and as the concentration of heavy metals increased, the stronger the inhibitory effect. Moreover, Pb and Cd have a synergistic effect under compound stress. (2) The accumulation and transfer rules of Pb and Cd ions in mulberry were different. The content of Pb in mulberry was root > leaf > stem and the content of Cd was root > stem > leaf. The combined stress promoted the transfer of Pb and Cd from the underground part to the aerial portion of mulberry. (3) The silkworm feeds on mulberry leaves contaminated with heavy metals in this experiment and found that: with the increase of silkworm feeding, the heavy metal content in the silkworm body increased significantly, but the content remained in the silkworm body was less, most of it was excreted with silkworm excrement. Combined stress has no significant effect on the detoxification mechanism of silkworm. It is indispensable to think of the synergistic effect of heavy metals on plants germination when seeds are used for phytoremediation.


Assuntos
Bombyx/fisiologia , Cádmio/toxicidade , Cadeia Alimentar , Chumbo/toxicidade , Morus/fisiologia , Poluentes do Solo/toxicidade , Solo/química , Animais , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Frutas/química , Metais Pesados/análise , Fotossíntese , Folhas de Planta/química , Plântula/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
13.
Ecotoxicol Environ Saf ; 208: 111584, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396107

RESUMO

Cadmium (Cd) is highly toxic for plant metabolic processes even in low concentration due to higher retention rates, longer half-life and non-biodegradable nature. The current study was designed to assess the bioremediation potential of Cd tolerant PGPR, Serratia sp. CP-13 together with two differentially Cd tolerant maize cultivars (MMRI-Yellow, Sahiwal-2002) selected amongst ten cultivars after screening. The maize cultivars were grown under different Cd treatments (0, 6, 12, 18, 24, 30 µM) in Petri plates both with and without Serratia sp. CP-13 inoculation. Treated plants were analyzed for their biomass accumulation, chlorophylls, carotenoids, proline, anthocyanin, protein, malondialdehyde (MDA), H2O2 as well as for antioxidants (POD, SOD, CAT) and mineral elements (Ca, Mg, Zn, K, Fe, Na, Cd). The maize cultivar MMRI-Yellow (tolerant) and Sahiwal-2002 (sensitive) exhibited significant reduction in leaf area, nutrient contents, plant biomass, activity of antioxidants, total proteins, photosynthetic pigments as well as flavonoids with increased production of H2O2, proline, MDA and relative membrane permeability (RMP) under Cd stress. However, this reduction was cultivar specific and recorded higher in cv. Sahiwal-2002 as compared to MMRI-Yellow. Application of Serratia sp. CP-13 significantly augmented plant biomass, photosynthetic pigments, antioxidative machinery, as well as flavonoids and proline while diminishing H2O2, RMP MDA production even under Cd stress in studied cultivars. Furthermore, CP-13 inoculation assisted the Cd stressed plants to sustain an optimal level of essential nutrients (Ca, Mg, Zn, K, Fe) except for Na and Cd which responded antagonistically. It was inferred that both inoculated maize cultivars exhibited better health and metabolism but substantial Cd tolerance was acquired by the sensitive cv. Sahiwal-2002 than the tolerant cv. MMRI-Yellow under applied Cd regimes. Furthermore, studied maize cultivars depicted maximum Cd tolerance in order of 30 < 24 < 18 < 12 < 6 < 0 µM Cd treatments under Serratia sp. CP-13 inoculation. Findings of current work highlighted the importance of Serratia sp. CP-13 and its inoculation impact on morpho-physio-biochemical attributes of maize growth under Cd dominant environment, which is likely an addition towards efficient approaches for bacterially-assisted Cd bioremediation and minimal Cd retention in edible plant parts.


Assuntos
Cádmio/toxicidade , Serratia/fisiologia , Poluentes do Solo/toxicidade , Zea mays/fisiologia , Antioxidantes/metabolismo , Biodegradação Ambiental , Transporte Biológico , Biomassa , Cádmio/metabolismo , Clorofila/metabolismo , Peróxido de Hidrogênio/metabolismo , Fotossíntese , Folhas de Planta/metabolismo , Serratia/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia
14.
Ecotoxicol Environ Saf ; 208: 111586, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396109

RESUMO

This research studies a typical landscape of an agricultural area separated from the road by a ditch with trees. Soils were sampled at 1, 2, 7, 25, and 50 m from the road. The concentrations of polycyclic aromatic hydrocarbons (PAH), total and phyto-available heavy metals (HM), total petroleum hydrocarbons (TPH), and de-icing salts (DS, Cl-) were determined using standard techniques. A set of higher plants (Lepidium sativum L., Sinapis alba L., Raphanus sativus L., Hordeum vulgare L., Avena sativa L.) was applied for toxicity evaluation of soils. The objective of this research is to find correlations between pollution of roadside soils and their phytotoxicity. HM, TPH and DS contamination of soils was observed in the 0-25 m zone, and PAH contamination was found up to the 50 m. Soil toxicity was declining from the road to the 50 m. Phytotoxicity related to majority of plants performed correlations with the same set of contaminants: TPH, 2-rings PAH, phyto-available Zn, Cu, Pb, and total Zn. No any correlations demonstrated Avena sativa L., being not applicable for ecotoxicological assessment of roadside soils. Despite the phytotoxicity was generally in line with contaminants loads, surprisingly low values were indicated in the ditch characterized by the strong pollution. We attribute this to the contrasting properties of soils there - the higher content of organics and clay. Sensitivity of plants to roadside pollution decreased in the row Lepidium sativum L. > Hordeum vulgare L. > Sinapis alba L. > Raphanus sativus L. The most reliable test-parameters for toxicity estimation were the root and the shoot length, germination rate was not informative indicating low phytotoxicity values. The research showed the importance of the right choice of test-cultures and test-parameters to judge phytotoxicity correctly. Linking the contaminants loads and phytotoxicity effects is valuable for comprehensive ecotoxicological assessment.


Assuntos
Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Agricultura , Ecotoxicologia , Monitoramento Ambiental/métodos , Poluição Ambiental , Hordeum , Hidrocarbonetos , Lepidium sativum , Metais Pesados/análise , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Sinapis , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
15.
Ecotoxicol Environ Saf ; 208: 111598, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396119

RESUMO

Within the domain of phytoremediation research, the proper disposal of harvestable plant parts, that remove pollutants from contaminated soil, has been attracted extensive attention. Here, the bioenergy generation capability of trace metals (Cu, Pb, Zn, Cd, Mn, and As) polluted plants was assessed. The biogas production potential of accumulators or hyperaccumulator plants, Elsholtzia haichowensis, Sedum alfredii, Solanum nigrum, Phytolacca americana and Pteris vittata were 259.2 ± 1.9, 238.7 ± 4.2, 135.9 ± 0.9, 129.5 ± 2.9 and 106.8 ± 2.1 mL/g, respectively. The presence of Cu (at approximately 1000 mg/kg) increased the cumulative biogas production, the daily methane production and the methane yield of E. haichowensis. For S. alfredii, the presence of Zn (≥500 mg/kg) showed a significant negative impact on the methane content in biogas, and the daily methane production, which decreased the biogas and methane yield. The biogas production potential increased when the content of Mn was at 5 000-10,000 mg/kg, subsequently, decreased when the value of Mn at 20,000 mg/kg. However, Cd (1-200 mg/kg), Pb (125-2000 mg/kg) and As (1250-10,000 mg/kg) showed no distinctive change in the cumulative biogas production of S. nigrum, S. alfredii and P. vittata, respectively. The methane yield showed a strong positive correlation (R2 =0.9704) with cumulative biogas production, and the energy potential of the plant residues were at 415-985 kWh/ton. Thus, the anaerobic digestion has bright potential for the disposal of trace metal contaminated plants, and has promising prospects for the use in energy production.


Assuntos
Anaerobiose , Biocombustíveis , Poluentes do Solo/análise , Oligoelementos/análise , Biodegradação Ambiental , Poluentes Ambientais , Metano , Plantas , Pteris/química , Sedum
16.
Ecotoxicol Environ Saf ; 208: 111600, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396120

RESUMO

Field experiments was conducted to evaluate the effectiveness of sepiolite (S), sepiolite + fungi residues (SFR) and sepiolite + vermicompost (SVC) on in situ immobilization remediation of Cd contaminated soils. The results showed that treatments of S, SFR and SVC decreased soil Cd availability by 15.2-47.8%, 17.5-44.9% and 13.2-44.9%, respectively, when compared with the control groups. Moreover, the content of Cd in edible parts of Lactuca sativa L., Cichorium endivia L. and Brassica campestris L. was experienced a decrease of 15.9-41.9%, 1.6-38.0% and 29.0-37.4% reduction, respectively, under the amended soil. The improvement of soil fertility was obtained under addition of SVC and SFR, while the amounts of available P, K, organic matter, microbial carbon, microbial nitrogen and dehydrogenase activity were increased by 9.6-68.2%, 1.2-28.3%, 37.5-70.5%, 4.1-121.0%, 220-640% and 6.8-56.8%, respectively, in contrast to CK. Moreover, high-throughput sequencing analysis showed that the combined treated soils got higher values of alpha diversity indices, Chao1, ACE and Shannon. The number of dominant phyla (Proteobacteria, Acidobacteria, Gemmatimonadetes, Crenarchaeota) and genera (Aquicella, Lysobacter, Candidatus Nitrososphaera, Sphingopyxis, Mesorhizobium) were enhanced. Therefore, the use of sepiolite and organic amendments could be an adequate strategy to immobilization remediation of Cd-contaminated soils.


Assuntos
Cádmio/análise , Recuperação e Remediação Ambiental , Poluentes do Solo/análise , Brassica , Poluição Ambiental , Silicatos de Magnésio , Solo/química , Microbiologia do Solo
17.
Environ Monit Assess ; 193(2): 54, 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33428009

RESUMO

The heavy metal pollution level in soils is heavily affected by the soil particle size distribution. However, the heavy metal loss during particle size extraction and the effect of calcite on the heavy metals removal in terms of the particle size are unclear. In this study, the distribution of heavy metals (Cu, Cd, Cr, Co, Ni, Zn, Pb, U, and V) was determined in five particle fractions (> 2, 2-0.25, 0.25-0.02, 0.02-0.002, and < 0.002 mm) of two soil and one sediment samples collected from the floodplain of Dongchuan, Yunnan Province, Southwest China. The sampled floodplain soils were mainly composed of gravel and sand fractions (> 97%). The concentrations of all nine heavy metals in the sampled soils and sediment increase significantly with decreasing particle sizes. The maximal loss rate of Cd and Cu reaches 54% and 8.6%, respectively, which should be considered in the process of particle size fraction extraction in soils. The removal amount and removal rate of heavy metals in solution by pure calcite ranks in the order of Pb2+ > Cu2+ > Cr6+, while the removal rate of Pb (93.13%) is much higher than that of Cu (24.56%) and Cr (10.71%), which increase with the calcite particle size decreasing. The stabilization of carbonate minerals in soils is crucial for heavy metal pollution control in floodplain soils with high carbonate concentrations in Dongchuan, China.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Metais Pesados/análise , Tamanho da Partícula , Solo , Poluentes do Solo/análise
18.
Environ Monit Assess ; 193(1): 17, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33389185

RESUMO

The bioaccessibility of some elements (As, B, Cd, Cu, Fe, Mn, Ni and Zn) in soils and vegetables was determined using the physiologically based extraction test. An investigation of the geochemical phases of soils through sequential extraction methods followed by ICP-MS detection was also undertaken. Samples were collected from Iskele, Begendikler and Yolbasi villages in the Bigadic region and Yildiz village in the Susurluk region of Balikesir province, Turkey. All of these villages are close to boron mines. Principal component analysis and correlation analysis demonstrated the interrelationship between the bioaccessibility values of these elements in the gastric and intestinal extracts of soils as well as the plant samples grown in those soils and the elements' concentrations in the different soil fractions. From the bioaccessible concentrations of the elements in the intestinal phases, it was shown that the amounts of As, B, Cu, Mn and Ni in some plant samples were higher than the recommended and tolerable values for human consumption. The bioaccessibilty of these elements in the soils and plants were statistically related with the concentrations of these elements in the labile phases of the soil. The methodology adopted here would be applicable to determining interactions between elements and soil fractions and the interrelationships between bioaccessibility data and soil fractions for any soil samples.


Assuntos
Poluentes do Solo , Solo , Boro , Monitoramento Ambiental , Humanos , Poluentes do Solo/análise , Turquia , Verduras
19.
Ecotoxicol Environ Saf ; 208: 111734, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396063

RESUMO

Hexavalent chromium [Cr(VI)] has strong mobility and it can enter into deep regions of soil. Cr(VI)-contaminated soil remediation is the process of removing Cr(VI) present in deep soils and any residual Cr(VI). In this study, the Cr(VI)-contaminated soil in Chongqing was investigated, and the remediation and economic feasibility of chemical leaching and reduction combined with a soil repairing approach was explored. The results showed that the leaching reagent, liquid-solid ratio, leaching time, reduction agent dosage, reduction temperature and reduction time had significant (P < 0.05) effects on the remediation of Cr(VI). At 0.02 mol/L oxalic acid and citric acid using a liquid-solid ratio of 5:1 and leaching time of 45 min, the removal rate of Cr(VI) was 62.7%, the residual Cr(VI) in soil was 126 mg/kg, and the soil pH was 4.09 after leaching. Between 25 and 90 °C, and at a molar ratio of 25:1 of FeSO4•7 H2O to Cr(VI), the reduction rate of Cr(VI) in soil after reduction was 54.0-98.4%, and the leaching concentration of Cr(VI) in soil was 0.01-0.29 mg/L. The optimal reduction was at 90 °C for 60 min, resulting in only 2.7 mg/kg of residual Cr(VI) in soil. The cost of this technology to treat the area studied was 826 ¥/ton of soil, which represents an economically feasible method for Cr(VI)-contaminated soil remediation.


Assuntos
Cromo/química , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/química , Ácido Cítrico , Poluição Ambiental , Ácido Oxálico , Solo , Poluentes do Solo/análise
20.
Ecotoxicol Environ Saf ; 208: 111737, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396065

RESUMO

Soils and artificial surfaces of urban parks can be contaminated by toxic substances and offer risk to the human health, especially to children. Rio Grande city, southern Brazil, is a peculiar site from the point of view of environmental contamination, since the current levels of contamination reflect an accumulation of different polluting sources started in the 18th century up to the urban and industrial sources of the present. The history of Hg contamination refers to the use of Hg salts in textile activities in the 18th century and the consequent use of contaminated sediments to land urban areas. The current contamination involves metals such as Cu, Ni, Pb and Zn is related to the high degree of urbanization in the city, as well as the petrochemical and fertilizer industry. The study aimed to achieve a human health risk assessment of urban parks soils, specifically for Cu, Hg, Ni, Pb and Zn. To carry out the risk assessment using the USEPA model, three urban parks with a history of contamination were studied, using different soil exposure pathways (oral, dermal and inhalation) in the carcinogenic (Ni and Pb) and non-carcinogenic (Cu, Hg, Ni, Pb and Zn) scenarios for children and adults. The non-carcinogenic risk of Pb was found in the three urban parks studied, for children and Hg in two urban parks. Pb and Ni showed no carcinogenic risk. Even so, the high non-carcinogenic risk of Hg and Pb showed that the contamination of the past and the present are found in the urban parks of Rio Grande city, putting the health of children who use these collective spaces at risk.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Poluição Ambiental/estatística & dados numéricos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Adulto , Brasil , Carcinógenos/análise , Criança , Cidades , Monitoramento Ambiental , Humanos , Indústrias , Mercúrio , Parques Recreativos , Medição de Risco
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