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A source classification framework supporting pollutant source mapping, pollutant release prediction, transport and load forecasting, and source control planning for urban environments Texte intégral
2012
Lützhøft, Hans-Christian Holten | Donner, Erica | Wickman, Tonie | Eriksson, Eva | Banovec, Primož | Mikkelsen, Peter Steen | Ledin, Anna
PURPOSE: Implementation of current European environmental legislation such as the Water Framework Directive requires access to comprehensive, well-structured pollutant source and release inventories. The aim of this work was to develop a Source Classification Framework (SCF) ideally suited for this purpose. METHODS: Existing source classification systems were examined by a multidisciplinary research team, and an optimised SCF was developed. The performance and usability of the SCF were tested using a selection of 25 chemicals listed as priority pollutants in Europe. RESULTS: The SCF is structured in the form of a relational database and incorporates both qualitative and quantitative source classification and release data. The system supports a wide range of pollution monitoring and management applications. The SCF functioned well in the performance test, which also revealed important gaps in priority pollutant release data. CONCLUSIONS: The SCF provides a well-structured approach for European pollutant source and release classification and management. With further optimisation and demonstration testing, the SCF has the potential to be fully implemented throughout Europe.
Afficher plus [+] Moins [-]Bioremediation of chromium by novel strains Enterobacter aerogenes T2 and Acinetobacter sp. PD 12 S2 Texte intégral
2012
Panda, Jigisha | Sarkar, Priyabrata
PURPOSE: This study had an objective to identify the most potent chromium-resistant bacteria isolated from tannery effluent and apply them for bioremediation of chromium in tannery effluents. METHODS: Two such strains (previously characterized and identified by us)—Enterobacter aerogenes (NCBI GenBank USA Accession no. GU265554) and Acinetobacter sp. PD 12 (NCBI GenBank USA Accession no. GU084179)—showed powerful chromium resistivity and bioremediation capabilities among many stains isolated from tannery waste. Parameters such as pH, concentration of hexavalent chromium or Cr (VI), and inoculum volume were varied to observe optimum bioconversion and bioaccumulation of Cr (VI) when the said strains were grown in M9 minimal salt media. E. aerogenes was used to remediate chromium from tannery effluents in a laboratory level experiment. RESULTS: Observation by Scanning Electron Microscope and chromium peak in Energy Dispersive X-ray Spectroscopic microanalysis revealed that E. aerogenes helped remediate a moderate amount of Cr (VI) (8–16 mg L−1) over a wide range of pH values at 35–37°C (within 26.05 h). High inoculum percentage of Acinetobacter sp. PD 12 also enabled bioremediation of 8–16 mg L−1 of Cr (VI) over a wide range of temperature (25–37°C), mainly at pH 7 (within 63.28 h). The experiment with real tannery effluent gave very encouraging results. CONCLUSION: The strain E. aerogenes can be used in bioremediation of Cr (VI) since it could work in actual environmental conditions with extraordinarily high capacity.
Afficher plus [+] Moins [-]Changing pollutants to green biogases for the crop food cycle chain Texte intégral
2012
Zong, B. Y. | Xu, F. J. | Zong, B. D. | Zhang, Z. G.
PURPOSE: When fossil fuels on the Earth are used up, which kind of green energy can be used to replace them? Do every bioenergy generation or crop food chain results in environmental pollution? These questions are major concerns in a world facing restricted supplies of energy and food as well as environmental pollutions. To alleviate these issues, option biogases are explored in this paper. MATERIALS AND METHODS: Two types of biogas generators were used for modifying the traditional crop food chain [viz. from atmospheric CO2 photosynthesis to crops, crop stem/husk biowastes (burnt in cropland or as home fuels), to livestock droppings (dumping away), pork and people foods, then to CO2], via turning the biowaste pollutants into green bioenergies. By analyzing the traditional food chain via observation method, the drawbacks of by-product biowastes were revealed. Also, the whole cycle chain was further analyzed to assess its “greenness,” using experimental data and other information, such as the material balance (e.g., the absorbed CO2, investment versus generated food, energy, and wastes). RESULTS AND DISCUSSION: The data show that by using the two types of biogas generators, clean renewable bioenergy, crop food, and livestock meat could be continuously produced without creating any waste to the world. The modification chain largely reduced CO2 greenhouse gas and had a low-cost investment. The raw materials for the gas generators were only the wastes of crop stems and livestock droppings. Thus, the recommended CO2 bioenergy cycle chain via the modification also greatly solved the environmental biowaste pollutions in the world. CONCLUSIONS: The described two type biogases effectively addressed the issues on energy, food, and environmental pollution. The green renewable bioenergy from the food cycle chain may be one of suitable alternatives to fossil and tree fuels for agricultural countries.
Afficher plus [+] Moins [-]Assessment of waters and sediments impacted by drainage at the Young Dong coal mine site, South Korea Texte intégral
2012
Woo, Kwangje | Lee, Ju Y. | Ji, Won H. | Khim, Jeehyeong
INTRODUCTION: This study focused on the assessment of the geochemistry and hydrology of the Imgok Creek–Young Dong tributary for the design of a field coal mine drainage treatment system. METHODS AND RESULTS: Examination of this site showed that the pH was greatly lowered by the addition of the Young Dong water, except in the month of March. The alkalinity was also affected; the concentrations of iron, aluminum, and sulfate were elevated at sites below the confluence; of these, iron was particularly problematic. High iron concentrations were primarily restricted to the acid rock drainage (ARD) (YD-9) water sources, whereas high aluminum concentrations were seen in both the ARD and in some of the upstream water sources. The acidity was primarily due to ferrous and ferric iron with a lesser amount of aluminum acidity. Except for the sampling in March, the flow was dominated by the ARD. This hydrologic condition resulted from the loads of iron, aluminum, sulfate, and acidity, among other constituents, that were dominated by the ARD. CONCLUSION: Finally, treatment activities should primarily focus on the ARD and specifically seek to remove ferrous and ferric iron from the treatment system.
Afficher plus [+] Moins [-]On the limits of the air pollution predictability: the case of the surface ozone at Athens, Greece Texte intégral
2012
Varotsos, Costas | Efstathiou, Maria | Tzanis, Chris | Deligiorgi, Despina
PURPOSE: The aim of this study is to investigate the potential effects of increased urbanization in the Athens city, Greece on the intrinsic features of the temporal fluctuations of the surface ozone concentration (SOC). METHODS: The detrended fluctuation analysis was applied to the mean monthly values of SOC derived from ground-based observations collected at the centre of Athens basin during 1901–1940 and 1987–2007. RESULTS: Despite the present-day SOC doubling in respect to SOC historic levels, its fluctuations exhibit long-range power-law persistence, with similar features in both time periods. This contributes to an improved understanding of our predictive powers and enables better environmental management and more efficient decision-making processes. CONCLUSIONS: The extensive photochemistry enhancement observed in the Athens basin from the beginning of the twentieth century until the beginning of the twenty-first century seems not to have affected the long memory of SOC correlations. The strength of this memory stems from its temporal evolution and provides the limits of the air pollution predictability at various time scales.
Afficher plus [+] Moins [-]Removal of Pb(II) ions from aqueous solution and industrial effluent using natural biosorbents Texte intégral
2012
Singha, Biswajit | Das, Sudip Kumar
PURPOSE: The purpose of the research is to investigate the applicability of the low-cost natural biosorbents for the removal of Pb(II) ions from aqueous solution and effluent from battery industry. METHODS: Six different biosorbents namely rice straw, rice bran, rice husk, coconut shell, neem leaves, and hyacinth roots have been used for the removal of Pb(II) ions from aqueous solution in batch process. All the biosorbents were collected from local area near Kolkata, West Bengal, India. The removal efficiency was determined in batch experiments for each biosorbent. RESULTS: The biosorbents were characterized by SEM, FTIR, surface area, and point of zero charge. The sorption kinetic data was best described by pseudo-second-order model for all the biosorbents except rice husk which followed intraparticle diffusion model. Pb(II) ions adsorption process for rice straw, rice bran, and hyacinth roots were governed predominately by film diffusion, but in the case of rice husk, it was intraparticle diffusion. Film diffusion and intraparticle diffusion were equally responsible for the biosorption process onto coconut shell and neem leaves. The values of mass transfer coefficient indicated that the velocity of the adsorbate transport from the bulk to the solid phase was quite fast for all cases. Maximum monolayer sorption capacities onto the six natural sorbents studied were estimated from the Langmuir sorption model and compared with other natural sorbents used by other researchers. The Elovich model, the calculated values of effective diffusivity, and the sorption energy calculated by using the Dubinin–Radushkevich isotherm were indicated that the sorption process was chemical in nature. The thermodynamic studies indicated that the adsorption processes were endothermic. FTIR studies were carried out to understand the type of functional groups responsible for Pb(II) ions binding process. Regeneration of biosorbents were carried out by desorption studies using HNO3. Battery industry effluents were used for the application study to investigate applicability of the biosorbents. CONCLUSION: The biosorbents can be utilized as low-cost sorbents for the removal of Pb(II) ions from wastewater.
Afficher plus [+] Moins [-]Embryonic exposure to low concentration of bisphenol A affects the development of Oryzias melastigma larvae Texte intégral
2012
Huang, Qiansheng | Fang, Chao | Chen, Yajie | Wu, Xinlong | Ye, Ting | Lin, Yi | Dong, Sijun
The prevalence of bisphenol A (BPA) in the environment has attracted increasing attention because of the toxicity of this manmade pollutant. However, the toxicity related to cardiac development remains largely unknown. In the present paper, we investigated the cardiac toxicity of BPA using marine medaka (Oryzias melastigma) embryos. At 2 days postfertilization (dpf), the embryos were continuously exposed to a low concentration of BPA (200 μg/L) for the whole embryonic stage. Heart rate and sinus venosus (SV)–bulbus arteriosus (BA) distance were measured under microscopy. The mRNA expression levels of genes were quantified by SYBR real-time RT-PCR, and hematoxylin and eosin (H&E) staining was used to examine the histology of fish larvae hearts. Neither the heart rate nor the SV-BA distance of the embryos was affected by BPA exposure. However, the mRNA expression levels of Na⁺–K⁺–ATPase, BMP4, COX-1, FGF8, GATA4, and NKX2.5 were all downregulated at the critical developmental stages (6 and 10 dpf). Interestingly, the mRNA expression levels of COX-2 and LERP were significantly upregulated at 10 dpf. The mRNA expressions of inflammation-related genes (TNFα, IL1β, SOD, and CCL11) were all significantly upregulated after exposure. Moreover, we found that both the body length and the body width decreased in the larvae after embryonic exposure to BPA. The distributed foci of inflammation were observed in the juveniles after 2 weeks’ depuration. Exposure to BPA at embryonic stages could alter the expression of heart development-related genes and inflammation-related genes of O. melastigma. The larvae hatched from exposed embryos showed the foci of inflammation in the heart ventricles and the decrease of the body length and width.
Afficher plus [+] Moins [-]GC-MS analyses and chemometric processing to discriminate the local and long-distance sources of PAHs associated to atmospheric PM2.5 Texte intégral
2012
Masiol, Mauro | Centanni, Elena | Squizzato, Stefania | Höfer, Angelika | Pecorari, Eliana | Rampazzo, Giancarlo | Pavoni, Bruno
PURPOSE: This study presents a procedure to differentiate the local and remote sources of particulate-bound polycyclic aromatic hydrocarbons (PAHs). METHODS: Data were collected during an extended PM2.5 sampling campaign (2009–2010) carried out for 1 year in Venice-Mestre, Italy, at three stations with different emissive scenarios: urban, industrial, and semirural background. Diagnostic ratios and factor analysis were initially applied to point out the most probable sources. In a second step, the areal distribution of the identified sources was studied by applying the discriminant analysis on factor scores. Third, samples collected in days with similar atmospheric circulation patterns were grouped using a cluster analysis on wind data. Local contributions to PM2.5 and PAHs were then assessed by interpreting cluster results with chemical data. RESULTS: Results evidenced that significantly lower levels of PM2.5 and PAHs were found when faster winds changed air masses, whereas in presence of scarce ventilation, locally emitted pollutants were trapped and concentrations increased. This way, an estimation of pollutant loads due to local sources can be derived from data collected in days with similar wind patterns. Long-range contributions were detected by a cluster analysis on the air mass back-trajectories. Results revealed that PM2.5 concentrations were relatively high when air masses had passed over the Po Valley. However, external sources do not significantly contribute to the PAHs load. CONCLUSIONS: The proposed procedure can be applied to other environments with minor modifications, and the obtained information can be useful to design local and national air pollution control strategies.
Afficher plus [+] Moins [-]Temporal and spatial changes of PAH concentrations in Mytilus galloprovincialis from Ria de Vigo (NW Spain) Texte intégral
2012
Viñas, Lucia | Franco, Angeles | Blanco, Xoana | Bargiela, Jessica | Soriano, Jose A. | Perez-Fernandez, Begoña | González, Juan José
The aim of this study was to establish the temporal trends and spatial distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Ria de Vigo by means of studying the PAH burden in wild mussels. The samples were collected in eight sites along the margins of the Ria de Vigo during November from 1998 to 2008 and Polycyclic Aromatic Hydrocarbon contents were determined using high performance liquid chromatography–fluorescence derivatization (HPLC–FLD). Quality of chemical analysis was guaranteed by participation in QUASIMEME intercalibration exercises carried out during the period of analysis. The concentrations for the sum of 13 PAHs were in the range 24–480 μg/kg dw, typical of an urban and industrialized area (50–500 μg/kg dw) except for a punctual input in La Guía in 1998 that led to a concentration above 1,000 μg/kg dw. In general, the sites in the outermost section of the estuary (ría) showed the lowest values, with an increasing gradient in the medium and inner parts of the ría. Temporal patterns show, in general, a downward trend. The relative proportion of 3 and 4 ring PAHs also varies with the site, the former being predominant in the outermost area and the latter in the medium and inner parts of the ría. This is consistently related with the sources and processes taking place in different areas of the estuary.
Afficher plus [+] Moins [-]Salt marsh macrophyte Phragmites australis strategies assessment for its dominance in mercury-contaminated coastal lagoon (Ria de Aveiro, Portugal) Texte intégral
2012
Anjum, Naser A. | Aḥmad, Iqbāl | Válega, Mónica | Pacheco, Mario | Figueira, Etelvina | Duarte, Armando C. | Pereira, Eduarda
Salt marsh macrophyte Phragmites australis strategies assessment for its dominance in mercury-contaminated coastal lagoon (Ria de Aveiro, Portugal) Texte intégral
2012
Anjum, Naser A. | Aḥmad, Iqbāl | Válega, Mónica | Pacheco, Mario | Figueira, Etelvina | Duarte, Armando C. | Pereira, Eduarda
INTRODUCTION AND AIMS: The dominance of a plant species in highly metal-contaminated areas reflects its tolerance or adaptability potential to these scenarios. Hence, plants with high adaptability and/or tolerance to exceptionally high metal-contaminated scenarios may help protect environmental degradation. The present study aimed to assess the strategies adopted by common reed, Phragmites australis for its dominance in highly mercury-contaminated Ria de Aveiro coastal lagoon (Portugal). MATERIALS AND METHODS: Both plant samples and the sediments vegetated by monospecific stand of Phragmites australis were collected in five replicates from mercury-free (reference) and contaminated sites during low tide between March 2006 and January 2007. The sediments’ physico-chemical traits, plant dry mass, uptake, partitioning, and transfer of mercury were evaluated during growing season (spring, summer, autumn, and winter) of P. australis. Redox potential and pH of the sediment around roots were measured in situ using a WTW-pH 330i meter. Dried sediments were incinerated for 4 h at 500°C for the estimation of organic matter whereas plant samples were oven-dried at 60°C till constant weight for plant dry mass determination. Mercury concentrations in sediments and plant parts were determined by atomic absorption spectrometry with thermal decomposition, using an advanced mercury analyzer (LECO 254) and maintaining the accuracy and precision of the analytical methodologies. In addition, mercury bioaccumulation and translocation factors were also determined to differentiate the accumulation of mercury and its subsequent translocation to plant parts in P. australis. RESULTS AND CONCLUSIONS: P. australis root exhibited the highest mercury accumulation followed by rhizome and leaves during the reproductive phase (autumn). During the same phase, P. australis exhibited ≈5 times less mercury-translocation factor (0.03 in leaf) when compared with the highest mercury bioaccumulation factor for root (0.14). Moreover, seasonal variations differentially impacted the studied parameters. P. australis’ extraordinary ability to (a) pool the maximum mercury in its roots and rhizomes, (b) protect its leaf against mercury toxicity by adopting the mercury exclusion, and (c) adjust the rhizosphere-sediment environment during the seasonal changes significantly helps to withstand the highly mercury-contaminated Ria de Aveiro lagoon. The current study implies that P. australis has enough potential to be used for mercury stabilization and restoration of sediments/soils rich in mercury as well.
Afficher plus [+] Moins [-]Salt marsh macrophyte Phragmites australis strategies assessment for its dominance in mercury-contaminated coastal lagoon (Ria de Aveiro, Portugal) Texte intégral
2012 | 1000
Anjum, N. A. | Ahmad, I. | Valega, M. | Pacheco, M. | Figueira, E. | Duarte, A. C. | Pereira, E.
Introduction and aims The dominance of a plant species in highly metal-contaminated areas reflects its tolerance or adaptability potential to these scenarios. Hence, plants with high adaptability and/or tolerance to exceptionally high metal-contaminated scenarios may help protect environmental degradation. The present study aimed to assess the strategies adopted by common reed, Phragmites australis for its dominance in highly mercury-contaminated Ria de Aveiro coastal lagoon (Portugal). Materials and methods Both plant samples and the sediments vegetated by monospecific stand of Phragmites australis were collected in five replicates from mercury-free (reference) and contaminated sites during low tide between March 2006 and January 2007. The sediments’ physico-chemical traits, plant dry mass, uptake, partitioning, and transfer of mercury were evaluated during growing season (spring, summer, autumn, and winter) of P. australis. Redox potential and pH of the sediment around roots were measured in situ using a WTW-pH 330i meter. Dried sediments were incinerated for 4 h at 500°C for the estimation of organic matter whereas plant samples were oven-dried at 60°C till constant weight for plant dry mass determination. Mercury concentrations in sediments and plant parts were determined by atomic absorption spectrometry with thermal decomposition, using an advanced mercury analyzer (LECO 254) and maintaining the accuracy and precision of the analytical methodologies. In addition, mercury bioaccumulation and translocation factors were also determined to differentiate the accumulation of mercury and its subsequent translocation to plant parts in P. australis. Results and conclusions P. australis root exhibited the highest mercury accumulation followed by rhizome and leaves during the reproductive phase (autumn). During the same phase, P. australis exhibited ≈5 times less mercury-translocation factor (0.03 in leaf) when compared with the highest mercury bioaccumulation factor for root (0.14). Moreover, seasonal variations differentially impacted the studied parameters. P. australis’ extraordinary ability to (a) pool the maximum mercury in its roots and rhizomes, (b) protect its leaf against mercury toxicity by adopting the mercury exclusion, and (c) adjust the rhizosphere-sediment environment during the seasonal changes significantly helps to withstand the highly mercury-contaminated Ria de Aveiro lagoon. The current study implies that P. australis has enough potential to be used for mercury stabilization and restoration of sediments/soils rich in mercury as well
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