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1.
Environ Pollut ; 259: 113838, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023785

RESUMO

To date limited information's are available concerning unintentional productions, screening, profiling, and health risks of polychlorinated naphthalenes (PCNs) in ambient environment and occupational environment. Literature reveals that dust is a neglected environmental matrix never measured for PCNs. To our knowledge, this is the first study to investigate the concentrations and health risks of PCNs in indoor dust, air, and blood of major e-waste recycling hubs in Pakistan. Indoor air (n = 125), dust (n = 250), and serum (n = 250) samples were collected from five major e-waste hubs and their vicinity to measure 39 PCN congeners using GC-ECNI-MS. ∑39PCN concentrations in indoor air, dust, and serum (worker > resident > children) samples ranged from 7.0 to 9583 pg/m3, from 0.25 to 697 ng/g, and from 0.15 to 401 pg/g lipid weight, respectively. Predominant PCN congeners in indoor air and dust were tri- and tetra-CNs, while tetra- and penta-CNs were dominant in human serum samples. The higher PCNs contribution was recorded at the recycling units, while the lower was observed at the shops of the major e-waste hubs. Higher contribution of combustion origin CNs in air, dust and human samples showed combustion sources at the major e-waste hubs, while Halowax and Aroclor based technical mixture showed minor contribution in these samples. Mean toxic equivalent (TEQ) concentrations of PCNs were 2.79E+00 pg-TEQ/m3, 1.60E-02 ng-TEQ/g, 8.11E-01 pg-TEQ/g, 7.14E-01 pg-TEQ/g, and 6.37E-01 pg-TEQ/g for indoor air, dust, and serum samples from workers, residents, and children, respectively. In our study, CNs- 66/67 and -73 in indoor air, dust, and human serum were the great contributors to total TEQ concentrations of PCNs. This first base line data directs government and agencies to implement rules, regulation to avoid negative health outcomes and suggests further awareness in regard of provision of proper knowledge to the target population.


Assuntos
Resíduo Eletrônico , Exposição Ambiental , Naftalenos , Criança , Poeira , Resíduo Eletrônico/efeitos adversos , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Naftalenos/análise , Naftalenos/química , Naftalenos/toxicidade , Paquistão , Medição de Risco
2.
Chemosphere ; 243: 125443, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995890

RESUMO

Long-term sampling is essential for monitoring the air pollutants emitted from stack since it can monitor the pollutants emission continuously including the stages of start-up, shutdown and normal operation. However, commercial continuous sampling equipment such as AMESA faces the challenges of high weight and complicated sampling procedures. This study has developed a long-term and automatic sampling system (National Central University continuous stack sampling system, NCU-CS3), and compared the efficiency with manual sampling train (MST). The results indicate that relative standard deviation (RSD) of PCDD/Fs concentrations measured between NCU-CS3 and MST is <20%, demonstrating that the difference between NCU-CS3 and MST in measuring PCDD/Fs is insignificant. Besides, the effects of adsorbent temperature, adsorbent amount and type of adsorbent on breakthroughs of PAHs and unintentional-persistent organic pollutants (UPOPs) such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), chlorinated phenols (CPs), chlorinated benzenes (CBs) and polychlorinated naphthalenes (PCNs) are evaluated. The results indicate that the breakthrough of pollutants increases with increasing temperature of XAD-2 and decreases with increasing XAD-2 amount. Moreover, XAD-4 is used as alternative adsorbent to test the breakthrough and the results indicate that the breakthroughs of UPOPs of XAD-4 as adsorbent are lower than that with XAD-2 due to higher specific surface area of XAD-4. Furthermore, the residual of PCDD/Fs with NCU-CS3 as the sampling train is relatively low (1.5-3.8%), which meets the regulation of EN 1948-5 (10%).


Assuntos
Poluentes Atmosféricos/análise , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Dibenzodioxinas Policloradas/análise , Benzofuranos/análise , Dibenzofuranos/análise , Poluentes Ambientais/análise , Estudos Longitudinais , Naftalenos/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
3.
Ecotoxicol Environ Saf ; 188: 109895, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31706238

RESUMO

Seventeen soil samples collected in an industrial park located in Ningxia Province, Northwestern China were analyzed for polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The PCN, PCDD/F, and PCB concentration ranges were 183-3340, 7.00-215, and 45.1-355 pg/g, respectively. Positive matrix factorization showed that secondary ferrous metal smelters and cement kilns contributed more than 70% of the total PCN concentration. Historical use of Halowax 1051 also affected the PCN concentrations in soil. Principal component analysis indicated that the PCDD/F concentrations in soil in the study area were mainly affected by thermal processes in secondary ferrous metal smelters. CB-209 was an important contributor to total PCBs in the study area, and likely originated from the phthalocyanine-type pigments used in a local recycled paper mill. Samples S10, S1, S17, and S6 had high ∑TEQ (PCDD/Fs + PCNs + PCBs) concentrations, and the carcinogenic risks of PCDD/Fs, PCNs, and PCBs for workers from these samples were 0.487 × 10-6, 0.234 × 10-6, 0.230 × 10-6, and 0.210 × 10-6, respectively. According to our results, the health risks of PCDD/Fs, PCNs, and PCBs for workers in this area should be given more attention.


Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Indústrias , Naftalenos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , China , Humanos , Medição de Risco , Solo/química
4.
Molecules ; 24(24)2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31861152

RESUMO

Electrochemical surface-enhanced Raman scattering (SERS) of the cruciform system 1,4-bis((E)-2-(pyridin-4-yl)vinyl)naphthalene (bpyvn) was recorded on nanostructured silver surfaces at different electrode potentials by using excitation laser lines of 785 and 514.5 nm. SERS relative intensities were analyzed on the basis of the resonance Raman vibronic theory with the help of DFT calculations. The comparison between the experimental and the computed resonance Raman spectra calculated for the first five electronic states of the Ag2-bpyvn surface complex model points out that the selective enhancement of the SERS band recorded at about 1600 cm-1, under 785 nm excitation, is due to a resonant Raman process involving a photoexcited metal-to-molecule charge transfer state of the complex, while the enhancement of the 1570 cm-1 band using 514.5 nm excitation is due to an intramolecular π→π* electronic transition localized in the naphthalenyl framework, resulting in a case of surface-enhanced resonance Raman spectrum (SERRS). Thus, the enhancement of the SERS bands of bpyvn is controlled by a general chemical enhancement mechanism in which different resonance processes of the overall electronic structure of the metal-molecule system are involved.


Assuntos
Metais/análise , Metais/química , Naftalenos/análise , Naftalenos/química , Análise Espectral Raman , Complexos de Coordenação/análise , Complexos de Coordenação/química , Teoria da Densidade Funcional , Eletroquímica , Modelos Químicos , Modelos Moleculares , Estrutura Molecular
5.
Environ Sci Pollut Res Int ; 26(34): 35218-35226, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31691896

RESUMO

Oxygen-releasing compounds (ORCs) have recently gained much attention in contaminated groundwater remediation. We investigated the impact of calcium peroxide nanoparticles on the groundwater indigenous bacteria in a bioremediation process by permeable reactive barrier (PRB). Three sand-packed columns were applied, including (1) control column (fresh groundwater), (2) natural remediation column (contaminated groundwater), and (3) biostimulation column (contaminated groundwater amended with CaO2). Actinobacteria and Proteobacteria constituted the main phyla among the identified isolates. According to the results of next-generation sequencing, Proteobacteria was the dominant phylum (81% relative abundance) in the natural remediation condition. But, it was declined to 38.1% in the biostimulation column. Meanwhile, the abundance of Actinobacteria and Bacteroidetes were increased to 25.9% and 15.4%, respectively, by exposing the groundwater microbial structure to CaO2 nanoparticles. Furthermore, orders Chlamydiales, Nitrospirales, and Oceanospirillales existing in the control column were detected in the presence of naphthalene. Shannon index was 4.32 for the control column samples, while it was reduced to 2.73 and 2.00 in the natural and biostimulation columns, respectively. Therefore, the present study provides a considerable insight into the impact of ORCs on the groundwater microbial community during the bioremediation process.


Assuntos
Água Subterrânea/química , Naftalenos/química , Peróxidos/química , Poluentes Químicos da Água/química , Bactérias , Biodegradação Ambiental , Água Subterrânea/microbiologia , Naftalenos/análise , Microbiologia da Água , Poluentes Químicos da Água/análise
6.
Ecotoxicol Environ Saf ; 185: 109707, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31561078

RESUMO

Effective biodegradation of hydrophobic pollutants, such as 1-chloronaphthalene, is strictly associated with the adaptation of environmental bacteria to their assimilation. This study explores the relation between the modifications of cell properties of bacteria belonging to Pseudomonas and Serratia genera resulting from a 12-month exposure to 1-chloronaphthalene, and their biodegradation efficiency. In the presented study, both bacterial strains exhibited higher (70%) degradation of this compound after exposure compared to unexposed (55%) systems. This adaptation can be associated with increased ratio of polysaccharides in the outer layers of bacterial cells, which was confirmed using infrared spectroscopy analysis. Additionally, the analysis of Raman spectra indicated conformational changes of extracellular carbohydrates from α- to ß-anomeric structure. Moreover, the changes in the cell surface hydrophobicity and cell membrane permeability differed between the strains and the Pseudomonas strain exhibited more significant modifications of these parameters. The results suggest that adaptation strategies of both tested strains are different and involve diverse reconstructions of the cell wall and membranes. The results provide a novel and deep insight into the interactions between environmental bacterial strains and chloroaromatic compounds, which opens new perspectives for applying spectrometric methods in investigation of cell adaptation strategies as a result of long-term contact with toxic pollutants.


Assuntos
Aclimatação/efeitos dos fármacos , Poluentes Ambientais/análise , Naftalenos/análise , Pseudomonas/efeitos dos fármacos , Serratia/efeitos dos fármacos , Biodegradação Ambiental , Poluentes Ambientais/toxicidade , Interações Hidrofóbicas e Hidrofílicas , Naftalenos/toxicidade , Polissacarídeos Bacterianos/metabolismo , Pseudomonas/metabolismo , Serratia/metabolismo
7.
Ecotoxicol Environ Saf ; 184: 109674, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31536846

RESUMO

The amounts and characteristics of polychlorinated naphthalenes (PCNs) emitted by a secondary copper smelter were investigated. Differences in the amounts and characteristics of PCNs emitted during different smelting stages were investigated, and the main stage during which PCNs were emitted was identified. PCN concentrations in stack gases emitted during secondary copper smelting were 477.0-762.5 ng/m3 (4.4-8.3 pg toxic equivalents/m3). The contributions of the different stages to total PCN emissions decreased in the order feeding-fusion stage (65% of total PCN emissions) > oxidation stage (27%) > deoxidation stage (8%). The main contributor to PCN emissions during secondary copper smelting was the feeding-fusion stage. PCN concentrations and profiles in stack gas, fly ash, and deposit ash collected during different smelting stages were determined. PCNs in stack gases were mainly less-chlorinated homologs, and fly ash and deposit ash were dominated by highly-chlorinated homologs. These results will help improve strategies for decreasing and eliminating PCN emissions during secondary copper production.


Assuntos
Poluentes Atmosféricos/análise , Cobre , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Metalurgia , Naftalenos/análise , China , Cinza de Carvão/análise , Gases/análise , Oxirredução
8.
Environ Pollut ; 255(Pt 1): 113096, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521997

RESUMO

The Chinese Government has established stringent policies since 2005 to control SO2, particulate matter, and NOx emissions from sintering plants with the aim of tackling severe air pollution in China. Notably, sintering is also important sources of polychlorinated naphthalenes (PCNs), but it is not clear whether the air pollution control policies have led to decreased PCN emissions. In this study, the PCN concentrations in 144 stack gas, 87 discarded fly ash, and 24 desulfurization by-product samples from 24 Chinese sintering plants were determined. This study revealed that desulfurization processes decreased PCN emissions by 47.2%-72.2%. However, these PCNs were not completely eliminated, and transformed to desulfurization by-product. PCN emission in such previously ignored solid residues, including of desulfurization by-product and fine particles, produced in the process of cutting down air pollutants emissions from Chinese sintering plants between 2005 and 2015 was found contained 324 kg, and these residues therefore need to be managed better than currently. Furthermore, PCN concentrations were higher from produced in old plants than produced in new plants, so it is necessary to increase the rate at which out-of-date sintering plants are eliminated. Phasing out old sintering processes decreased total PCN emissions in China by 1549 kg between 2005 and 2015.


Assuntos
Poluentes Atmosféricos/análise , Cinza de Carvão/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Indústrias , Naftalenos/análise , Poluição do Ar/prevenção & controle , China
9.
J Agric Food Chem ; 67(49): 13487-13495, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31347368

RESUMO

The occurrence in Riesling wine of the potent odorant 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) is dependent upon vineyard and winemaking conditions, and TDN can have a prominent impact on the attributes of a wine after years in a bottle. As such, immediately assessing the impact of vineyard or winery treatments on future TDN formation requires forced creation of the aroma compound under non-wine-like conditions from other precursors. Here, we use a Box-Behnken approach and known TDN end points in commercial wines to optimize the conditions (pH, temperature, and time) of a "total TDN" hydrolytic assay for Riesling wine, which was intended to not interfere with yeast-derived formation pathways. The new assay (75 °C, pH 1.7, and 60 min) was used to determine the role of industry-relevant commercial yeasts as well as novel hybrid yeast strains on total TDN concentrations in young Riesling wines. While significant differences were observed between some yeasts, the impact of defoliation as a viticultural intervention outweighed yeast effects, suggesting that elevated TDN concentrations in wine are likely due to grape growing conditions and cannot be readily reduced or compensated for in the winery.


Assuntos
Naftalenos/análise , Naftalenos/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Fermentação , Frutas/metabolismo , Frutas/microbiologia , Odorantes/análise , Vitis/metabolismo , Vitis/microbiologia
10.
Environ Sci Pollut Res Int ; 26(24): 25142-25153, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31254193

RESUMO

The three-dimensional quantitative structure-activity relationship (3D-QSAR) model is established for polychlorinated naphthalenes (PCNs) using the biological degradability (total score) results to modify CN-56 to design 37 new derivatives with higher degradability (increased by 14.55-38.79%). Furthermore, five new CN-56 derivatives are selected through evaluation of their persistent organic pollutant properties (toxicity, bioconcentration, long-range transport) and practicability (stability, insulativity, flame retardancy) using 3D-QSAR, density functional theory (DFT) and molecular docking methods. Environmental and health-based risk assessments are conducted using the multimedia fugacity model and fuzzy theory for complete screening of the new CN-56 derivatives. Whereas CN-56 is classed as high risk, three new derivatives can be classed as medium risk. The biodegradability mechanism analysis of the PCNs indicates that the electrostatic property is the main factor that affects the degradability, which provides a favorable theoretical reference to obtain environmentally friendly fire retardant and insulating materials.


Assuntos
Poluentes Ambientais/análise , Naftalenos/análise , Biodegradação Ambiental , Poluentes Ambientais/química , Simulação de Acoplamento Molecular , Naftalenos/química , Relação Quantitativa Estrutura-Atividade , Medição de Risco , Eletricidade Estática
11.
Environ Monit Assess ; 191(7): 417, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31172293

RESUMO

Ingestion of leafy vegetables is an important dietary component of most Africans due to its health benefits. High levels of polycyclic aromatic hydrocarbons (PAHs) in the leafy vegetables may pose a significant health hazard to the consumers. Rose/Hibiscus, Chinese cabbage, lettuce, and garden egg leaves from farms along the Nima Creek, Accra, were selected. At each sampling site, the vegetable was uprooted and cut into leaves, stem, and root and analyzed differently. The GC-MS method was employed in the identification and quantification of 16 PAHs in the samples. The analysis was done at CSIR - Water Research Institute Organic Laboratory. The results obtained show concentrations of acenapththylene, acenapthene, benzo[a]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene (except chrysene and pyrene which were found in garden egg leaves and Chinese cabbage respectively), while naphthalene was detected in all the vegetables. The mean concentration of phenanthrene in leaves, stem, and roots of Chinese cabbage vegetable varies according to the following order: roots (0.744 ± 0.16 µg/kg) ≥ leaves (0.598 ± 1.21 µg/kg) ≥ stem (0.327 ± 1.01 µg/kg). From the results of the isomeric ratios, the source of the PAHs in the leafy vegetables are from mixed sources, i.e., either pyrogenic and petrogenic origins. This calls for the formulation of stringent policies on the importation of over-age vehicles into the countries as well as on the indiscriminate burning of materials containing PAHs.


Assuntos
Brassica/química , Monitoramento Ambiental/métodos , Hibiscus/química , Alface/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Verduras/química , Acenaftenos/análise , Benzo(a)Antracenos/análise , Benzo(a)pireno/análise , Dieta , Fazendas , Fluorenos/análise , Inocuidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Gana , Naftalenos/análise , Fenantrenos/análise
12.
J Chromatogr A ; 1602: 74-82, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31176481

RESUMO

The purpose of this study was to develop a new method for the sampling and analysis of naphthalene (Nap) and phenanthrene (Phe) in air. XAD-2 sorbent was prepared with polyaniline (PANI) to increase its adsorption area. Thus, 22-gauge needles were packed with XAD-2/PANI sorbent for the extraction of Nap and Phe, and sampling of the analytes of interest. The compounds were dynamically sampled from the headspace of the flask in laboratory and then analyzed using a gas chromatography (GC) device equipped with flame ionization detector (FID). The needle trap device (NTD) with the proposed sorbent was more sensitive and accurate than the NIOSH 5515 method. The results showed that the optimal temperature and time for the desorption of the analytes were 350 °C and 8 min, respectively. The analytical parameters such as carryover effect, breakthrough volume, and storage time were examined. The repeatability of the method was determined to be 9.4-13.5% for Nap and 7.1-15.7% for Phe. The limits of detection (LOD) for the analytes were in the range 0.002 - 0.09 ng L-1, and the limits of quantitation (LOQ) were in the range 0.01- 0.23 ng L-1. It was also found that the NTD packed with XAD-2/PANI sorbent was a sensitive and cost-effective method, and offered a high accuracy for the sampling and analysis of PAHs in air.


Assuntos
Poluentes Atmosféricos/análise , Compostos de Anilina/química , Técnicas de Química Analítica/instrumentação , Naftalenos/análise , Fenantrenos/análise , Adsorção , Poluentes Atmosféricos/isolamento & purificação , Cromatografia Gasosa , Ionização de Chama , Limite de Detecção , Agulhas , Hidrocarbonetos Policíclicos Aromáticos/análise , Temperatura
13.
Chemosphere ; 231: 240-248, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31129405

RESUMO

A retrospective analysis of a number of historical medicinal grade cod liver oil samples produced in Northern Europe revealed relatively high contamination levels of PCNs, PCDD/Fs and PCBs. The total toxic equivalence (TEQ) associated with PCDD/Fs, dl-PCBs and PCNs was in the range 95-427 pg g-1 for Baltic cod liver oils and from 70 to 148 pg g-1 for oils sourced from the North Atlantic. The corresponding range for canned cod liver products (Baltic Sea) sampled in 2017 ranged from 52 to 104 pg g-1 fat (33-34 pg g-1 ww). The contribution from PCBs to the overall TEQ toxicity was around 3-6-fold higher than from PCDD/Fs and ranged from 24 to 318 pg TEQ g-1ww. The estimated summed TEQ intakes of PCDD/Fs, dl-PCBs and dl-PCNs resulting from the consumption of the daily recommended doses was highest for the Baltic cod liver oils ranging from 16 to 293 pg kg-1 body mass (bm) day-1 for an adult, 20-183 pg kg-1 bm day-1 for a teenager and 15-131 pg kg-1 bm day-1 for a child. The contribution to daily adult TEQ intake from PCNs alone, although relatively small is estimated to contribute up to 5-fold above the recent EFSA proposed TWI of 2 pg kg-1 bm. The results indicate that although currently produced fish oils may undergo rigorous purification procedures and show low contaminant levels, cod livers sourced from the Baltic and consumed locally, continue to contribute substantially to the dietary intake of these contaminants.


Assuntos
Exposição Ambiental/análise , Óleos de Peixe/análise , Contaminação de Alimentos/estatística & dados numéricos , Poluentes Químicos da Água/análise , Adulto , Criança , Dibenzofuranos Policlorados/análise , Dioxinas/análise , Exposição Ambiental/estatística & dados numéricos , Europa (Continente) , Óleos de Peixe/química , Contaminação de Alimentos/análise , Furanos/análise , Humanos , Fígado/química , Naftalenos/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análise , Estudos Retrospectivos
14.
Chemosphere ; 230: 559-566, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31125884

RESUMO

Large volume of multidimensional data can be summarised, both in terms of tabulated statistics, and as graphic geospatial visualisations. The latter approach allows rapid interpretation and communication of complex information to stake-holders such as regulators, risk assessors and policy makers. In the main study on polychlorinated naphthalene (PCN), individual samples representing different edible fish species were analysed from around the UK. PCNs were observed in all samples with nearly all of the twelve measured congeners being detected. Summed congener concentrations ranged from 0.7 ng/kg ww (turbot) to 265 ng/kg ww (sprats). The highest contamination levels were recorded for sprats and mackerel with mean summed concentrations of 67 ng/kg ww and 68 ng/kg ww respectively. Two ancillary studies, on potentially toxic elements (PTEs) in crabs from China and aflatoxin in children's blood from Tanzania, demonstrate the wide applicability of this approach. The PTE contents in crab showed strong dependence on the tested tissues and elements, and crabs from Tai and Yangcheng Lakes showed obviously higher PTE levels than the other lakes. Geospatial distribution of the aflatoxin biomarker AF-alb in children's serum from 3 locations showed how individual anthropometric or socio-economic data reveals the relationship between family size, socio-economic score and magnitude of serum aflatoxin levels. In addition to facilitating the flow of interpreted data to stakeholders, these techniques can direct the formulation of risk mitigation activities and help with the identification of data gaps. When combined with hierarchical cluster analyses, correlations within the data can also be predicted.


Assuntos
Aflatoxinas/sangue , Monitoramento Ambiental/métodos , Contaminação de Alimentos/análise , Substâncias Perigosas/análise , Naftalenos/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Biomarcadores/sangue , Braquiúros/química , Criança , China , Sistemas de Informação Geográfica , Substâncias Perigosas/sangue , Humanos , Lagos/análise , Análise Espacial , Tanzânia , Poluentes Químicos da Água/sangue
15.
Chemosphere ; 226: 492-501, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953894

RESUMO

Metallurgical processes are currently the predominant anthropogenic sources of multiple unintentional persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), chlorinated and brominated PAHs (Cl-PAHs and Br-PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ether (PBDEs). Understanding the formation of multiple POPs is important for source control. These POPs could be formed through fly ash-mediated heterogeneous reactions. In this study, we comprehensively investigated the thermochemical (150-450 °C) formation of these POPs on fly ash samples collected from a secondary aluminum smelter, secondary lead smelter, and iron ore sintering plant. The maximum concentrations of PCNs and PCBs were 154.5 and 181.3 times those in the original fly ash, respectively. Formation variations of PAHs, Cl-PAHs and Br-PAHs, and PBDEs were different from that of PCBs and PCNs. The PAHs concentration, which was the highest among the POPs in the original fly ash, decreased sharply by 95% at 150 °C. The ∑19Cl-PAHs and ∑19Br-PAHs increased marginally at 250 °C before decreasing slightly at 350 °C. The PBDE concentrations decreased under 250 °C and increased at 350 °C. PCNs, PCBs, and PCDD/Fs showed good correlations, all of which had a negative relationship with the PAHs. There were no significant correlations between PAHs and Cl/Br-PAHs. Low brominated congeners could be formed by destruction of higher brominated congeners because of thermal instability of the PBDEs.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Éteres Difenil Halogenados/análise , Naftalenos/análise , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Halogenação , Metalurgia
16.
Environ Sci Pollut Res Int ; 26(13): 12731-12740, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30879233

RESUMO

Secondary aluminum smelting industry, as an important source of polychlorinated naphthalene (PCN) in environment, has been concerned in recent years. To figure out the emission characteristics of PCNs and the potential influence on surrounding environment, two typical secondary aluminum smelting plants were selected and PCNs were determined in flue gas, fly ash, aluminum slag, soil, and air samples collected at and around the plants by GC-MS coupled with DFS. PCN emission factors from the flue gas of the two plants (mean 0.006 ng toxic equivalents/t) were found obviously decreased compared with similar smelting process detected in 2010. The stage of feeding material was still the major PCNs discharge period during the whole smelting process. The total PCN concentrations in air were found to be ranked as following: workshops (290-1917 pg/m3), the area near the workshops (62.3-697 pg/m3), and the surrounding areas (29.9-164 pg/m3, mean 64.5 pg/m3). Similar high concentrations of PCNs were found in soil from by the workshop door (983 ng/g dry weight). Soil-air exchange calculations indicated that mono-CN to tetra-CN would volatilize but hepta-CN and octa-CN would be deposited to the soil. Exposure of plant workers and local inhabitants to PCNs through inhalation was found to be acceptable but higher (especially for workers in the workshops) than living areas. The workshop and the nearby area are potential PCNs polluted areas and should be paid attention during the practical operation.


Assuntos
Poluentes Atmosféricos/análise , Metalurgia , Naftalenos/análise , Poluentes do Solo/análise , Alumínio , Atmosfera , China , Cinza de Carvão/análise , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/análise , Inalação , Naftalenos/química , Exposição Ocupacional/análise , Medição de Risco
17.
Water Sci Technol ; 79(2): 240-250, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30865595

RESUMO

Toxic heavy metals and organic pollutants simultaneously exist in the wastewater of some industries. This study explores reduction of toxic divalent nickel ions, from either nitrate or sulfate salts, coupled with naphthalene (NA) degradation using titania photocatalyst in an efficient photo-sono reactor. A synergism appears when reduction and degradation treatments occur simultaneously in the media. With initial concentrations of [Ni(II)]0 = 5 mg/L and [NA]0 = 10 mg/L, under dominant mild conditions, removal efficiencies of 54.5% and 56.6% were obtained for Ni(II) and NA, respectively, when nickel nitrate was used. These efficiencies were enhanced to 59.2% and 57.5%, respectively, with nickel sulfate, all after 90 min operation. For evaluating the mechanism of reactions, reactive oxygen species analysis on solutions as well as Fourier transform infrared, scanning electron microscopy and Brunauer-Emmett-Teller analyses on the titania nanoparticles, before and after usage, was performed. The reaction kinetics was also followed for individual species in the mixed solution and, accordingly, the energy consumption was evaluated for one order of magnitude decrease in pollutant concentration. The high performance of the used method was revealed in comparison to the similar reported reduction/degradation processes.


Assuntos
Poluentes Ambientais , Modelos Químicos , Naftalenos/química , Níquel/química , Poluentes Químicos da Água/química , Cinética , Naftalenos/análise , Níquel/análise , Soluções , Água , Poluentes Químicos da Água/análise
18.
Ecotoxicol Environ Saf ; 174: 384-389, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30849659

RESUMO

Sediment samples were collected from a large reservoir and a river in northern Taiwan to investigate the occurrence and characteristics of Σ73PCNs analyzed. Results indicate that total concentrations of PCNs (Di- to Octa-CNs) measured in sediments collected in reservoir (29.2 ±â€¯7.11 pg/g-dw) are significantly lower than that of samples collected in river (987 ±â€¯440 pg/g-dw). The increasing trend of PCN concentration from upstream to downstream is found for the sediments collected in reservoir. PCN concentrations measured in surface sediments are relatively higher than that measured in sub-surface sediments collected in reservoir. Tetra-CNs consistently dominate in reservoir sediments, however, Penta-, Tetra- and Mono-CNs dominate in sediments collected at different sampling sites of the river investigated, suggesting that various sources contribute to PCNs collected from river. Indeed, diagnostic ratios indicate that mix-source contribute to PCNs measured in sediments collected from the reservoir and river in northern Taiwan.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Naftalenos/análise , Rios/química , Poluentes Químicos da Água/análise , Taiwan
19.
Environ Sci Pollut Res Int ; 26(12): 12563-12573, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30850981

RESUMO

The occurrence of plastic particles in aquatic environment has led to enormous concern in the past few years. The sorption behaviors of harmful organic compounds by plastic particles can increase their concentrations by several orders of magnitude influencing their global transport in the marine environment. Five types of mesoplastics (5-20 mm) and five types of microplastics (< 5 mm) were selected to investigate the sorption behaviors of three typical organic compounds (phenanthrene, nitrobenzene, and naphthalene). For phenanthrene, most microplastics have stronger sorption ability than that of mesoplastics due to the higher specific surface area (SSA). However, the sorption ability of nitrobenzene on low-density polyethylene (LDPE) mesoplastics was higher than that on LDPE microplastics, and the sorption ability of naphthalene on polyvinyl chloride (PVC) mesoplastics was higher than that on PVC microplastics, which were attributed to the presence of functional groups on the surface of mesoplastics, induced by adding slip agents, lubricant, plasticizer, stabilizer, etc. during film production. Talcum-filled polypropylene (PP) microplastics had strongest sorption ability to nitrobenzene and naphthalene due to the presence of talcum and high SSA. For unmodified microplastics, the sorption abilities of phenanthrene, nitrobenzene, and naphthalene were all followed the order of high-density polyethylene (HDPE) > polystyrene (PS) > LDPE > PVC after SSA normalization. Thus, SSA and the functional groups on the surface of plastic particles should be considered when the sorption behaviors of harmful organic compounds on plastic particles are studied.


Assuntos
Poluentes Ambientais/química , Modelos Químicos , Plásticos/química , Hidrocarbonetos Policíclicos Aromáticos/química , Adsorção , Poluentes Ambientais/análise , Naftalenos/análise , Naftalenos/química , Nitrobenzenos/análise , Nitrobenzenos/química , Compostos Orgânicos , Fenantrenos/análise , Fenantrenos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Polietileno , Polipropilenos , Poliestirenos , Cloreto de Polivinila
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 216: 202-206, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-30901705

RESUMO

The use of Sudan black B as coloring agent in foods is forbidden for its toxicology effect on human organs. This work proposes an efficient and sensitive method for food security inspection targeting Sudan black B. Surface-enhanced Raman spectroscopy (SERS) is applied to the analysis of trace Sudan black B. It could be detected at concentrations as low as 0.05 mg/L in standard solutions and 0.1 mg/kg in black rice extracts with the SERS method for measurement. The linear relationship between the intensity and concentration could be used for the quantitative detection of Sudan black B. The relation between dyeing time of black rice stained by Sudan black B solution and SERS intensity was studied which indirectly showed the effectiveness of the extraction method we designed. The results of the quantitative analysis reveal the practicability of using this method to detect Sudan black B in black rice. As a rapid and sensitive detection method, SERS can be extended to detect other food products and has a great application prospect in food safety inspection.


Assuntos
Compostos Azo/análise , Corantes/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Naftalenos/análise , Oryza/química , Análise Espectral Raman/métodos , Análise de Alimentos/economia , Inocuidade dos Alimentos , Fatores de Tempo
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