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1.
Water Sci Technol ; 81(10): 2244-2249, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32701501

RESUMO

Anthropogenic activities such as oil exploration have resulted in an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous bacterial communities have enhanced tolerance to heavy metals, we isolated and characterized culturable lead-resistant bacteria from an oil wastewater sample and determined whether they could reduce lead ions from the medium. The wastewater sample containing indigenous bacteria were taken out from a traditional oil field, Bojonegoro District, East Java, Indonesia, and bacteria were cultured Halomonas complex (HMC) medium containing lead (II) chloride (PbCl2) with different concentrations. Bioaccumulation of lead by heavy-metals resistant bacteria was determined by using atomic absorption spectrophotometry (AAS). Our result found 21 bacterial strains that resist lead ions, of which one strain (RPb5-3) highly resisted to 10 mM. This bacterial strain also exhibited the highest accumulation of Pb, and it could grow at various temperatures, or more than their original environment. The bacterial strains could be used for bioremediation of lead toxicity, especially in oil pollutants.


Assuntos
Metais Pesados , Águas Residuárias , Bactérias , Biodegradação Ambiental , Indonésia , Chumbo
2.
Water Sci Technol ; 81(9): 1797-1827, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666937

RESUMO

Industrial development has led to generation of large volumes of wastewater containing heavy metals, which need to be removed before the wastewater is released into the environment. Chemical and electrochemical methods are traditionally applied to treat this type of wastewater. These conventional methods have several shortcomings, such as secondary pollution and cost. Bioprocesses are gradually gaining popularity because of their high selectivities, low costs, and reduced environmental pollution. Removal of heavy metals by sulfate-reducing bacteria (SRB) is an economical and effective alternative to conventional methods. The limitations of and advances in SRB activity have not been comprehensively reviewed. In this paper, recent advances from laboratory studies in heavy metal removal by SRB were reported. Firstly, the mechanism of heavy metal removal by SRB is introduced. Then, the factors affecting microbial activity and metal removal efficiency are elucidated and discussed in detail. In addition, recent advances in selection of an electron donor, enhancement of SRB activity, and improvement of SRB tolerance to heavy metals are reviewed. Furthermore, key points for future studies of the SRB process are proposed.


Assuntos
Metais Pesados , Sulfatos , Bactérias , Biodegradação Ambiental , Águas Residuárias
3.
Environ Monit Assess ; 192(8): 504, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651666

RESUMO

The study of trace and major elements in the biosphere has traditionally focused on the transition and basic metals; the rare earth (REMs), alkaline earth (AEMs) and alkali metals (AMs) that equally constitute environmental contaminants are rarely considered especially in the tropics. The levels and spatial variation of some REMs, AEMs and AMs in the 0-50-cm layer of agricultural soils of Ikwo in southeastern Nigeria typing a humid tropical environment were studied. Soil sampling was undertaken at five zones namely north, south, east, west and centre (covering over 60% of the land area) in the 2017 dry season. Four soil samples were collected from each of the four cardinal points (with evidence of mining and agricultural activities), and two from the centre (serving as reference zone), totalling 18. Metal concentrations were determined using inductively coupled plasma atomic emission spectroscopy. The metals were grouped into REMs (Ce, La, Sm), AEMs (Ba, Ca, Mg, Sr) and AMs (Cs, K, Na, Rb). All metals increased in concentration from the north, or the south (for Ce and Sm only), towards the centre. Overall, they were reasonably similar in distribution pattern among the five zones. Cationic ratios did not vary markedly, reflecting the greater role of pedogenesis than anthropogenic activities in the area. Nevertheless, their variations showed more K, Ca, Sr and La enrichments over the other metals. Enrichment factor and pollution index of the REMs showed healthy levels of these elements in the soils. The data from this preliminary study may add to the data pool on levels and occurrence of REMs, AEMs and AMs in largely disturbed ecosystems of the humid tropics.


Assuntos
Metais Alcalinos , Metais Pesados/análise , Poluentes do Solo/análise , Ecossistema , Monitoramento Ambiental , Nigéria , Rizosfera , Solo
4.
J Environ Manage ; 270: 110517, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721279

RESUMO

The Yamuna is one of the most polluted rivers in India and the land adjacent to river flowing through Delhi city is widely irrigated with its water for growing various food crops. Present study was undertaken to assess the heavy metal load in Yamuna water and surrounding soils of the river bank and its impact on soil enzyme activities. Long term impact of irrigation by Yamuna water on the activities of various soil enzymes namely dehydrogenase (DHA), urease (UA), fluroscein diacetate (FDA), aryl sulphatase (ASA), nitrate reductase (NRA), microbial biomass carbon (MBC) and potentially mineralizable nitrogen (PMN) were assessed. The sensitivity of soil enzymes to heavy metals were observed as DHA>UA>ASA>NRS. Total organic carbon, easily oxidisable soil organic carbon, available phosphorus and available potassium in different sites varied significantly. Total heavy metal contents in soils showed a decreasing order: Fe>Mn>Zn>Cr>Ni>Cu>Pb>Co>As>Cd and the DTPA extractable heavy metal contents followed the order: Mn>Cu>Pb>Zn >Fe>Ni>Cd>Cr>Co>As. Potential ecological risk factors (Er) were under low risk and comprehensive potential ecological risk indices (Ri) were found to be under low, moderate and high risk categories. Copper (Cu) is the main pollutant contributing considerable load to Ri. From (Ri) principal component analysis and cluster analysis, it is evident that the Okhla site (S8) is most contaminated. The water from Yamuna river needs to be cautiously used for growing various food crops on land adjacent to the river as its long-term usage might cross the permissible limits of heavy metals in the soil.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Carbono , China , Cidades , Monitoramento Ambiental , Índia , Medição de Risco , Fatores de Risco , Rios , Solo
5.
J Environ Manage ; 270: 110824, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721299

RESUMO

Lignocellulosic biomass has been widely introduced into the liquefaction process of sewage sludge (SS) to improve the yield/quality of liquefaction products (bio-oil/biochar). This study explores the effect of adding rice straw (RS) and wood sawdust (WS) on the transport/conversion behaviors of heavy metals (HMs) during the liquefaction of SS. The introduction of lignocellulosic biomass, especially for RS, substantially lowers the total content of HMs in biochar. Most HMs (except Cd) still remain in biochar, although the introduction of RS/WS enhances the transport of HMs into bio-oils. The addition of RS/WS raises the percentage of HMs in active form, but the contents of bioavailable/leachable HMs are not considerably increased and even decreased in some cases, especially when RS is introduced. The overall pollution degree and environmental risk of HMs in biochars are lowered to a certain extent with the addition of RS/WS. Considering that the pollution degree and environmental risk of HMs present in biochars are still at a considerable level, appropriate pollution management measures should be undertaken when using such biochars for agricultural use.


Assuntos
Metais Pesados , Oryza , Biomassa , Carvão Vegetal , Esgotos , Madeira
6.
J Environ Manage ; 270: 110826, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721300

RESUMO

Microbial fuel cell (MFC) technology has emerged as a new and attractive bioelectrochemical approach in the last one and a half decade that offers an alternative to conventional treatment methods to remove and recover heavy metals and organics from wastewaters with simultaneous energy production. This technique has advantage over the conventional wastewater treatment techniques, which are energy intensive, sludge producing and with little effectivity at high concentrations. Significant work has been done in the recent years on MFC principle, electrode configuration, biofilm composition, application of MFC in wastewater treatment, metal removal or recovery and energy production. Basically, metal in the cathode chamber acts as acceptor of the electrons released from the oxidation of organic matter in the anode chamber by electrogenic microbes. Literature shows that efficacy of MFCs in removal and recovery of metals and power production is significantly influenced by redox potential of the metal, initial concentration, mix metal systems, carbon source in substrate, pH, biocathode, biofilm composition, gaseous environment in cathode, electrode modification and external resistance, which have been critically reviewed for the first time in the present paper to understand the role of the determinant factors that may be explored for improvement of the MFC performance. The paper provides further insights into the techno-economic aspects of MFC technology and suggests research needs for enhanced performance and reduced costs to increase its feasibility for application at commercial level.


Assuntos
Fontes de Energia Bioelétrica , Metais Pesados , Eletricidade , Eletrodos , Esgotos , Águas Residuárias
7.
J Environ Manage ; 270: 110873, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721316

RESUMO

Metals are key materials extensively employed in several industries to produce technological and daily-life products. The mining industry that produces such commodities generates Tons of waste that if not remediated can be transferred to the surrounding environment, thus representing a water, air, and soil pollution threat. In this work, we evaluated the feasibility of microbial sulfate reduction (SR) as a management strategy for this waste. Mine tailings were sampled from two abandoned mining sites located in Sonora (northwestern Mexico) and treated in anaerobic microcosms under SR conditions using anaerobic sludge as the inoculum at two different tailing:inoculum ratios (TIR). Major TIR's were found to be the triggering factor for the highest SR activities observed (73.6 ± 8.8 mg SO42- L-1 day-1). This stimulation was linked to the dissolution of sulfate bearing minerals (anglesite, jarosite, and gypsum) which provided additional sulfate for microbial activity. However, under this condition, longer lag phases for SR were observed, which was potentially due to pH inhibition at early incubation stages (pH ~3.7). Despite this, all biologically SR performing treatments presented important sulfide precipitation which was associated to changes in the mineralogy of the mine tailings. Metals of environmental concern such as As, Cd, Co, Cr and, Pb were detected to have shifted from the aqueous extractable phase to the bound to Fe and Mn oxides and residual phases. This finding was in accordance with the non-detectable concentrations of these metals in the aqueous phase by the end of the biological treatment which proved the effectiveness of this approach. This study provides insights into the promising potential of anaerobic microbes for the environmental management of mine tailings.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Conservação dos Recursos Naturais , Monitoramento Ambiental , Poluição Ambiental/análise , México , Mineração
8.
J Environ Manage ; 270: 110938, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721356

RESUMO

The application of biogas slurry, from anaerobic digestion of livestock excreta, to cropland has proven to be an effective mechanism for recycling nutrients within farms. However, the potential pollution of heavy metals from repeated biogas slurry fertilization has not received much attention. Here we present the results of a field experiment under rice-wheat rotation demonstrating the accumulation, speciation distribution and plant uptake of heavy metals (Cu, Zn, Pb and Cd) in soil following biogas slurry application. The treatments were: zero biogas slurry application (BS0), and biogas slurry application for three (BS3) and five (BS5) years, at a rate of 450 m3 ha-1 y-1. Our findings show that biogas slurry fertilization resulted in accumulation of Cu and Zn in the soil. The concentrations of soil Cu and Zn under BS5 were, respectively, 38 and 29% greater in the wheat season and 35 and 35% greater in the rice season relative to BS0 (p < 0.05). The bioavailability of soil Cu and Zn increased following biogas slurry application. Plant uptake of Cu and Zn to all parts of wheat and rice plants (excluding Cu in wheat straw) increased with the years of biogas slurry application (p < 0.05), and the concentration of Cd in wheat grain was significantly greater in BS5 relative to BS0 (p < 0.05). After five years of biogas slurry fertilization, concentrations of Cu, Zn, Pb and Cd in wheat grains were 3.28, 25.19, 0.11 and 0.053 mg kg-1 and 4.24, 33.78, 0.12 and 0.035 mg kg-1 for rice grains, respectively, all within the safety limits. Our results demonstrate that repeated biogas slurry fertilization for five years has a relatively low pollution risk of heavy metals. However, long-term field monitoring and co-application with metal-immobilizing materials are required to ensure the safety of its application to cropland.


Assuntos
Metais Pesados/análise , Oryza , Poluentes do Solo/análise , Biocombustíveis , China , Produção Agrícola , Monitoramento Ambiental , Solo , Triticum
9.
Environ Monit Assess ; 192(7): 466, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32602080

RESUMO

The concentrations of six heavy metal/metalloids (HMs) cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), and arsenic (As) were determined in the influent, effluent, and dewatered sludge of two sewage treatment works (Yuen Long Sewage Treatment Work (YLSTW) and Shek Wu Hui Sewage Treatment Work (SWHSTW)) and river waters and sediment (Shan Pui River and Ng Tung River) within the Mai Po Ramsar site in Hong Kong SAR, China. In both STWs, Pb had the highest removal efficiencies (YLSTW 86.5 ± 19.0% to 97.3 ± 3.04%; SWHSTW 87.4 ± 12.8% to 100 ± 0.0800%). In the whole effluent toxicity test, both STWs were effective in lowering the toxicity of the effluent to zebrafish and cherry shrimp. The environmental risk assessments of these HMs on three local aquatic organisms, three species of fish, two species of crustaceans, and three species of algae, were calculated based on measured HMs concentrations in river water and sewage samples, and the predicted no-effect concentrations. Results showed that Zn concentrations in all collected samples posed potential risks to all studied aquatic organisms (average risk quotient = 445). The concentrations of Cu in the rivers posed potential risks (average risk quotient = 5.42) to all fish species. It was concluded that Zn and Hg derived from the STWs might pose potential risks to the living organisms inhabiting the Ramsar site, and Cu, Cd, Pb, and As in the rivers were originated from the two rivers and possibly other tributaries.


Assuntos
Metaloides/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , China , Monitoramento Ambiental , Sedimentos Geológicos , Hong Kong , Medição de Risco , Rios , Esgotos
10.
Huan Jing Ke Xue ; 41(2): 691-701, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608728

RESUMO

The Le'an River is a main tributary of the Poyang Lake, which is the largest freshwater lake in China. The aim of this study is to research the distribution and potential ecological risks of heavy metals in the middle and lower reaches of the Le'an River, which is contaminated by nearby copper mines. Sediment and water samples were collected from 12 stations during the dry, wet, and normal season in 2016, respectively. The geo-accumulation index and potential ecological risk index were used to determine general pollution characteristics of trace metals in sediments. Results suggested that sediments in the Le'an River were considerably polluted by Cd, Pb, Cu, and Zn. Sediment concentrations of heavy metals showed significant spatial variations. The concentrations of heavy metals such as Cu, Zn, and Cd in water are higher in the dry season than in the normal and wet seasons. The distribution of heavy metals along the river is influenced by hydraulic conditions. The flow velocities in wet and normal seasons are positively correlated with the concentrations of heavy metals such as Cd, Pb, Cu, and Cr. There are seasonal differences in the distribution characteristics of heavy metals in surface sediments. In the dry season, the concentration of heavy metals in sediments is the highest in the middle reaches of rivers near mining areas, while during the wet and normal season, it reaches the highest value in the lower reach near the estuary. Except for Cd, whose major form of heavy metal in the sediment is in an exchanging state, the other heavy metals occur mainly in stable states. The assessment of the geo-accumulation index showed significant Cu, Cd, and Cr pollution. Among the heavy metals investigated, Cd was likely to result in more harmful effects.


Assuntos
Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Sedimentos Geológicos , Medição de Risco , Análise Espaço-Temporal
11.
Huan Jing Ke Xue ; 41(2): 815-822, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608742

RESUMO

Antibiotic resistance genes (ARGs) in municipal wastewater pose a potential threat to the environment. In this study, the change in absolute and relative abundance of ARGs, metal resistance genes (MRGs), and mobile genetic elements (MGTs) were investigated during an emergent municipal wastewater treatment by the magnetic separation process. Results indicate that all the concentrations of targeted ARGs, MRGs, and MGTs decreased significantly in the primary and secondary stirring tank. However, the absolute abundance of some ARGs and MRGs increased in the effluent, which is likely caused by the presence of ample MGTs, in the order of int1 (2.00×1010 copies·mL-1) > int2 (1.91×108 copies·mL-1) > Tn 916/1545e(5.38×108 copies·mL-1). The results obtained from network and PCA analysis showed that the removal of ARGs and MRGs were significantly associated with variations in the microbial community and common pollutants in urban wastewater, such as suspended solids, phosphorus, and COD, which are important factors for affecting the removal efficiency of antibiotic resistance genes and metal heavy resistance genes. These results show that magnetic separation can effectively reduce common pollutants in urban wastewater and might further restrict the transmission and transfer of ARGs. Moreover, it is necessary to strengthen the subsequent management of magnetic separation effluent and dehydrated sludge by disinfection technologies to lessen the risk of antimicrobial contamination.


Assuntos
Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Magnetismo , Águas Residuárias , Purificação da Água/métodos , Antibacterianos , Metais Pesados
12.
Huan Jing Ke Xue ; 41(2): 979-985, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608760

RESUMO

Chelating agents can increase the bioavailability of heavy metals and enhance their enrichment in plants. The effects of different concentrations of biodegradable chelating agent L-glutamic acid N, N-diacetic acid (GLDA) on the remediation of heavy metal-contaminated soil by super-enriched plant Trifolium repens were investigated by pot experiments with Cd-contaminated soil. Results show that low-dose GLDA could significantly promote the growth of Trifolium repens, and the biomass of Trifolium repens was the highest at 2.5 mmol·kg-1-GLDA, which was 1.30 times that of the control group. Different concentrations of GLDA can increase Cd content of various parts of Trifolium repens. In general, the treatment effect of 5 mmol·kg-1 GLDA was ideal. In this scenario, the root, aerial parts, and whole Cd content were 3.57, 4.69, and 4.67 times of the control group, respectively. GLDA can significantly increase the available Cd content in soil, promote direct absorption at the Trifolium repens roots, and provide better transport to the aerial parts. The prediction model obtained by fitting the linear relationship between physical and chemical properties of soil indicates that GLDA and Trifolium repens Cd content can provide references for the future research of soil-Trifolium repens enrichment. Studies have shown that the biodegradable chelating agent GLDA has potential applications for enhancing phytoremediation of heavy metal Cd contaminated soil.


Assuntos
Cádmio/metabolismo , Glutamatos , Glicina/análogos & derivados , Poluentes do Solo/metabolismo , Trifolium/metabolismo , Biodegradação Ambiental , Ácido Glutâmico , Metais Pesados
13.
Huan Jing Ke Xue ; 41(2): 986-996, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608761

RESUMO

The environmental risks posed by heavy metals (HMs) in animal manure are increasing because of the use of trace metals as additives in feedstuffs. Manure samples were collected, and published literature was reviewed in this study to systematically analyze the HMs content in animal manure and compare the results to different sources of animal manures. Results show that the distribution of HMs content in animal manure was skewed. The ranges were between not detected (ND)-147 mg·kg-1 for Cd, ND-1919 mg·kg-1 for Pb, 0.003-2278 mg·kg-1 for Cr, ND-978 mg·kg-1 for As, ND-103 mg·kg-1 for Hg, ND-1747 mg·kg-1 for Cu, ND-11547 mg·kg-1 for Zn, and 1.22-1140 mg·kg-1 for Ni. The means (medians) of those elements were 2.31(0.72) mg·kg-1, 13.5(8.96) mg·kg-1, 36.3(12.0) mg·kg-1, 14.0(3.52) mg·kg-1, 0.97(0.07) mg·kg-1, 282(115) mg·kg-1, 656(366) mg·kg-1, and 21.8 (13.1) mg·kg-1 for Cd, Pb, Cr, As, Hg, Cu, Zn, and Ni, respectively. Means were significantly higher (1-13 times) than the medians. According to maximum limits of Cd, Pb, Cr, As, and Hg for organic fertilizers NY 525-2012, about 12.3% (for Cd), 2.58% (for Pb), 2.76% (for Cr), 20.6% (for As), and 3.69% (for Hg) of the data were above the limits. According to the composting regulations of Germany, about 53.9% (for Cu), 45.7% (for Zn), and 0.59% (for Ni) exceeded the maximum limits. The heavy metal contents in animal manure of different regions differs significantly. As and Cd contents in animal manure in the Shandong Province tend to be higher with their average values at 1.7 times and 10.1 times of the mean contents for national scale, respectively; the heavy metal contents in eastern China tend to be higher. Cd and As contents in animal manure tend to be higher in Northeast and Eastern China, while Cu and Zn contents were higher in Eastern and South China. After comparing HMs content in different sources of manures, we found that Cd, As, Hg, Cu, Zn, and Ni mean contents in pig manure were 1.0-3.0 times, 1.8-6.8 times, 1.1-15.8 times, 4.9-17.5 times, 2.7-12.0 times, and 1.7-2.1 times that of cattle manure, sheep manure, and poultry manure. The Pb content in poultry manure was the highest, with the mean being 2.8, 2.5, and 2.2 times higher than pig manure, cattle manure, and sheep manure, respectively. When recycling animal manure into the crop field, the accumulation rates for Cd were under 0.02 mg·(kg·a)-1 in over 90% of the circumstances and the accumulation rates for Pb were all below 0.15 mg·(kg·a)-1. When applying poultry manure, Cr in soil is easily accumulated with the maximum accumulation rate of 0.28 mg·(kg·a)-1.


Assuntos
Esterco/análise , Metais Pesados/análise , Poluentes do Solo/análise , Animais , Bovinos , China , Monitoramento Ambiental , Medição de Risco , Ovinos , Solo/química , Suínos
14.
Environ Monit Assess ; 192(7): 477, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32613560

RESUMO

This study assessed some physicochemical properties and heavy metal contamination of four major dumpsites in Nsukka metropolis. Soil samples were collected randomly at depth of 15 cm. Physicochemical properties were determined. Levels of lead, chromium, iron, manganese, zinc, cadmium, and copper were analyzed using atomic absorption spectrophometer (AAS). Soil pH ranged 5.68-6.82, temperature 25.30-29.67 ° C, and moisture 2.23-7.66%. Soil particle size distribution had higher percentages of sand 40-55% followed by silt 15-35% and clay 10-30%. Average levels of Pb, Cr, Fe, Mn, Zn, Cd, and Cu from the dumpsites ranged from 0.08 ± 0.04 mg/kg to 1.40 ± 0.15 mg/kg, 0.17 ± 0.09 mg/kg to 1.66 ± 0.87 mg/kg, 14.05 ± 5.13 mg/kg to 21.08 ± 0.01 mg/kg, 4.47 ± 0.54 mg/kg to 16.83 ± 0.80 mg/kg, 9.10 ± 3.05 mg/kg to19.33 ± 0.12 mg/kg, 0.02 ± 0.01 mg/kg to 1.15 ± 0.30 mg/kg, and 0.77 ± 0.26 mg/kg to 7.29 ± 2.65 mg/kg, respectively. Heavy metal profile in the dumpsite soils was Fe > Zn > Mn > Cu > Cr > Pb > Cd. Heavy metal load by dumpsites was Obimo > Ikenga Hotel > UNN > Obukpa. All the heavy metals evaluated except Fe increased as pH, temperature, and sand contents of dumpsite soil increased. Retention of Fe by soil was positively related to its clay contents. The values of heavy metals in soils from the dumpsites were far below the permissible limits set by European Regulatory Standard (EURS STD), US Environmental Protection Agency (USEPA), and Federal Environmental Protection Agency (FEPA) for standard soil. The dumpsites require no remediation as at the time of this study.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Monitoramento Ambiental , Nigéria , Solo
15.
Environ Monit Assess ; 192(8): 485, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32617680

RESUMO

The Karkonosze National Park is affected by long-distance metal air transport of anthropogenic contamination as well as by tourist activity. Therefore, concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were evaluated in soil as well as in vital and non-vital fronds of Athyrium distentifolium Opiz collected in the middle of the growing season from glacial cirques in the Karkonosze. Additionally, fronds of the same species turning brown in autumn were collected from the same sampling sites. The health of ferns was impacted by the contents of Co, Cu, Fe, Mn, Ni, Pb and Zn in fronds, which may indicate that A. distentifolium uses elements accumulated in its tissues as defence against pathogens. Individuals from higher altitudes contained higher concentrations of Cd, Cu, Ni, Fe and Pb than those from lower altitudes. Autumn fronds of A. distentifolium contained a significantly higher concentration of Cr, Cu, Fe, Mn and Pb than vital summer fronds, which may indicate sequestration of these elements in senescing fronds probably to remove potentially harmful metals. Non-vital ferns were a better accumulator of Pb than vital ones, while both types of ferns accumulated Mn in a similar way.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Oligoelementos/análise , Monitoramento Ambiental , Humanos , Metais/análise , Polônia
16.
Environ Monit Assess ; 192(7): 483, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32617683

RESUMO

This study aimed to investigate the accumulation of heavy metal in five different leafy green vegetables grown in 10 different agricultural lands in the province of Nevsehir, Turkey, and determine the human health risks that may arise as a result the consumption of such metals. The heavy metal concentrations found in the soil samples taken from the agricultural lands were as follows: manganese (Mn) > lead (Pb) > arsenic (As) > nickel (Ni) > copper (Cu) > cadmium (Cd). These concentrations were found to be well above the permitted limits imposed by the World Health Organization/Food and Agricultural Organization (WHO/FAO) and the United States Environmental Protection Agency (USEPA). Also, particularly the concentrations of Pb and As were found to be dangerous levels in the soil. According to their accumulation in the vegetables, the detected heavy metal concentrations were listed as Mn > Zn > Cu > Ni > As > Cd. The estimated daily intake amount of the heavy metals was also found to be higher than the limits determined by FAO/WHO. Furthermore, the target hazard quotient of the metals was Mn > As > Cu > Zn > Ni > Cd > Pb. It was found to be > 1 for the sampling areas, except for Cd and Pb. As a result of the study, it was determined that almost all of the annual heavy metal intake amount that the population living in this region should receive was met as a result of the consumption of leafy vegetables grown in the stations designated for this study. It is vital to effectively monitor the heavy metal in the soil and vegetables to reduce metal concentrations in the studied area and to investigate its effects on human health. By doing so, acute and chronic health problems due to the heavy metal exposure in this region can be prevented.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Humanos , Medição de Risco , Turquia , Verduras
17.
Environ Monit Assess ; 192(8): 541, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32710394

RESUMO

Coal preparation by-products, such as coal gangue, are inferior fuels enriched with trace elements (TEs). Owing to the issues surrounding the disposal of coal preparation by-products and energy shortages, Chinese researchers have strongly advocated harvesting energy from by-products. However, the secondary environmental pollution caused by such by-products has been overlooked. In this study, we aimed to assess the contamination of soil and maize (Zea mays L.) near a coal gangue-fired power plant (CGPP) in Liupanshui City, Guizhou Province, China, by TEs. The contents of 11 TEs (Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, V, and Zn) in soil samples and different maize tissues were measured, and their chemical speciation in soil was also determined. The results showed that the soil in the study area was polluted by the above elements to varying degrees at a very high potential ecological risk. The Cr and Pb levels in niblets of partial samples exceeded the Chinese food safety standards. The TE contents of maize tissues largely depend on the bioavailable fraction of the same elements in the soils, rather than their total contents. Pearson's correlation and hierarchical cluster analyses resulted in three clusters:(1) Pb-Zn-Cd; (2) Co-Cu-Mn-Sb-V-Be; and (3) Cr-Ni. Coal preparation by-products should not be directly combusted without pre-treatment. These results will aid readers and engineers in understanding the adverse effect of CGPPs and provide regulators and policymakers with relevant data to scientifically guide the utilisation of coal preparation by-products.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , China , Carvão Mineral/análise , Monitoramento Ambiental , Centrais Elétricas , Medição de Risco , Solo , Zea mays
18.
Environ Monit Assess ; 192(8): 542, 2020 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-32712724

RESUMO

Due to industrial, rural, and domestic waste disposal, heavy metals such as cadmium (Cd), chromium (Cr), lead (Pb), zinc (Zn), copper (Cu), and iron (Fe) continually infiltrate aquatic environments. These pollutants do not degrade naturally and, thus, have a high capacity for bioaccumulation in tissues and organs. The present study uses histological and immunohistochemical analyses to evaluate the contamination status of Salminus franciscanus, a large and economically important fish. Levels of Cd, Cr, Pb, Zn, Cu, and Fe were evaluated by atomic absorption spectrometry in the liver and muscle of fish sampled from two tributaries of the upper São Francisco River Basin, Brazil: the Abaeté and Paraopeba Rivers. In addition, histopathological alterations and expressions of three environmental biomarkers were assessed: metallothionein (MT), heat shock protein-70 (HSP70), and cytochrome P450-1A (CYP1A). The results show that fish from the Paraopeba River are unsuitable for human consumption, with several metals being detected above the safe limits established by the World Health Organization. Histopathological alterations in the liver and spleen were also significantly more frequent in fish from the Paraopeba River than in those from the Abaeté River (P < 0.05). Significant differences in the expressions of environmental biomarkers were observed between the rivers. Fish from the Abaeté River presented significantly higher values of the gonadosomatic index (GSI) and lower levels of metal contamination in the liver and muscle.


Assuntos
Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Monitoramento Ambiental , Humanos , Rios
19.
Water Sci Technol ; 81(7): 1471-1478, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32616699

RESUMO

SiO2 gel was formed on the grain surface of silica sand by hydrolysis and condensation of tetraethyl orthosilicate in water with the addition of 1-butylamine. The resultant product was a composite consisting of sand grains with mesoporous silica coating containing alkylamine inside. This composite exhibited basicity in the wastewater from copper electroplating due to its release of amine. As a result, the strongly acidic wastewater was neutralized and the co-precipitation of complex metal ions occurred. It was shown that up to 12 major metal ions in the wastewater could be simultaneously removed under static condition at room temperature by using the sand composite. The Fe and Cu in the wastewater could be removed completely, while the concentrations of Al, Cd, Ti, V, and Zn in the wastewater were reduced by two to three orders of magnitude. After the removal of multiple metal ions from the electroplating wastewater, the used sand was further applied as a raw material for making a silicate glass. The glass was chemically stable and thus the heavy metal ions from the wastewater were immobilized.


Assuntos
Metais Pesados/análise , Poluentes Químicos da Água/análise , Cobre , Galvanoplastia , Íons , Areia , Dióxido de Silício , Águas Residuárias
20.
Water Sci Technol ; 81(7): 1507-1517, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32616702

RESUMO

The main point of this research is to assess the applicability of condensed molasses soluble (CMS), which is an organic by-product of lysine fermentation, as an environmentally friendly complexing agent in rhizofiltration of heavy metal contaminated acid mine drainage (AMD). First, the ecotoxicological properties (growth inhibition, seed germination) of CMS were examined with often applied indicator plant species such as duckweed (Lemna minor) and lettuce (Lactuca sativa) so as to define the possible applicable CMS concentration. Then the heavy metal accumulation and translocation properties of root accumulator plant species, i.e. common reed (Phragmites australis) and sedge (Carex flacca), were studied to optimize CMS concentration for rhizofiltration. Due to the CMS application, significant increase in bioaccumulation was detected in the case of every examined heavy metal (As, Cd, Cu, Pb and Zn) at the end of the experiment. Results also showed that CMS increased the heavy metal concentration in shoots, but did not affect the root accumulation characteristics of the plants. Furthermore, CMS treated plants accumulated heavy metals at higher rates in their roots compared to control. The results suggest that CMS is a viable additive and a complexing agent to aid rhizofiltration of heavy metal contaminated AMD.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Biodegradação Ambiental , Fermentação , Lisina , Mineração , Raízes de Plantas
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