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Distribution of beach litter along the coastline of Cádiz, Spain Texte intégral
2016
Williams, Allan Thomas | Randerson, Peter | Di Giacomo, Carlo | Anfuso, Giorgio | Macias, Ana | Perales, José Antonio
A total of 59 categories of litter items were found at 20 beaches (13 mechanically cleaned, 7 non-cleaned) in the Cádiz tourist environment, Spain. Cluster Analysis and Principal Components Analysis were used to highlight similarities and contrasts between sites and/or associations between litter categories. Multivariate analyses separated beaches according to the total numbers of litter items present. Non-cleaned sites showed a variety of litter category abundance with distinct origins and abundant, ubiquitous items (plastic and glass fragments). Of the 7 non-cleaned beaches (49 litter categories) river-mouth sites were distinct due with high numbers of litter items. The sheltered inner part of Cádiz Bay beaches had a wide range of litter type. Many sites were associated with locally deposited recreational litter categories; while industrial/commercial/fishing categories were abundant only at a few sites, indicating items transported onto the shore from the Guadalete river.
Afficher plus [+] Moins [-]Trace element mobility in a polluted marine sediment after stabilisation with hydraulic binders Texte intégral
2016
Saussaye, L. | Hamdoun, H. | Leleyter, L. | van Veen, E. | Coggan, J. | Rollinson, G. | Maherzi, W. | Boutouil, M. | Baraud, F.
The management of dredged marine sediment is an issue for many harbours, particularly when contaminant concentrations prevent disposal at sea. The stabilisation/solidification of the sediments with hydraulic binders for a use in road subgrade layer is a potential alternative solution. However, the environmental acceptability is not yet fully established. This paper presents the results of a case study to comprehensively determine the stabilisation of As, Cd, Cr, Cu, Ni, Pb and Zn. After demonstrating that stabilisation/solidification affects the microstructure of the sediment, a mobility study is realised (single, sequential and kinetic extractions). According to the regulatory/technical guidelines the studied elements do not pose a risk to the environment. However, results from more complex mobility studies reveal that stabilisation in the short term is only effective for Ni while other elements are mobilised after treatment by at least one type of extraction. Stabilisation in the long term is not universally effective.
Afficher plus [+] Moins [-]The new Landsat 8 potential for remote sensing of colored dissolved organic matter (CDOM) Texte intégral
2016
Slonecker, E Terrence | Jones, Daniel K. | Pellerin, Brian A.
Due to a combination of factors, such as a new coastal/aerosol band and improved radiometric sensitivity of the Operational Land Imager aboard Landsat 8, the atmospherically-corrected Surface Reflectance product for Landsat data, and the growing availability of corrected fDOM data from U.S. Geological Survey gaging stations, moderate-resolution remote sensing of fDOM may now be achievable. This paper explores the background of previous efforts and shows preliminary examples of the remote sensing and data relationships between corrected fDOM and Landsat 8 reflectance values. Although preliminary results before and after Hurricane Sandy are encouraging, more research is needed to explore the full potential of Landsat 8 to continuously map fDOM in a number of water profiles.
Afficher plus [+] Moins [-]Trace element concentration in surface sediments of Palk Strait, southeast coast of Tamil Nadu, India Texte intégral
2016
Kasilingam, K. | Suresh Gandhi, M. | Krishnakumar, S. | Magesh, N.S.
The present work was carried to decipher the trace element accumulation in surface sediments of Palk Strait, southeast coast of Tamil Nadu, India. The elemental concentration and correlation results suggest that fine fractions with CaCO3 content followed by organic matter (OM) of the surface sediments control the trace element accumulation in the study area. In addition, Fe and Mn concentration is chiefly contributed from riverine process and controlled by the mangrove ecosystem. The other elements are derived into marine environment through confluence of untreated industrial pollutants into the river system. The EF result shows that the studied marine sediments are enriched by Ni, Mn, Cu, Pb, Cd, Cr, followed by Zn. The order of the pollution intensity with respect to geo-accumulation index suggests the following ascending order: Ni>Mn>Fe>Cu>Pb>Cd>Cr>Zn. Pollution Load Index (PLI) values reveal that all the samples are falling under moderately to unpolluted category.
Afficher plus [+] Moins [-]Polybrominated diphenyl ethers (PBDEs) in mussels from cultures and natural population Texte intégral
2016
Dosis, Ioannis | Athanassiadis, Ioannis | Karamanlis, Xanthippos
Polybrominated diphenyl ether (PBDE) mass fractions were determined in mussel samples collected from 6 locations around Thermaikos Gulf in north Greece. PBDEs were present in all sampling sites and the average total (ΣPBDEs) ranged from 17.7 to 32.3ng/g l.w., characterising Thermaikos as low polluted, a fact further supported by congener ratios and literature comparison. Distribution was even among stations with one exception. Congener profiles exhibited predominance of penta-/octa-BDEs as well as BDE-209. Statistical analysis showed significant difference in pollution levels between the two types of mussel cultures. No variations were observed for mussel bunch position or between cultures and natural population. Congener correlation analysis suggested different pollution sources between higher and lower brominated congeners as well as different metabolic/degradation processes. Bioaccumulation factors indicated that an increase in congener bromination degree leads to bioaccumulation capacity reduction. Consumption of mussels from Thermaikos gulf area poses no threat for public health concerning PBDEs.
Afficher plus [+] Moins [-]Plastic ingestion by a generalist seabird on the coast of Uruguay Texte intégral
2016
Lenzi, Javier | Burgues, María Fernanda | Carrizo, Daniel | Machín, Emanuel | Teixeira-de Mello, Franco
We analyzed plastic ingestion by Kelp Gull (Larus dominicanus) from 806 pellets collected between 2011 and 2013. Employing a Raman spectroscopy, we characterized those polymers used to produce the plastics ingested. Debris was recorded in 143 pellets (%FO=17.7%, n=202, 92.58g). Plastic was found in 119 pellets (%FO=83%) and non-plastic occurred in 56 pellets (%FO=39%). The most important debris category was plastic film with 55.3% (n=79). Plastic bags were observed in 19 pellets (%FO=2.4%, weight=25.02g). Glass was the second most important component (%FO=18.9%) followed by plastic fragments (%FO=17.8%). Plastic debris represented the 65.3% of the debris fragments (n=132, weight=58.84g), and was composed by polyethylene (52%), polypropylene (26%), polyamide (12%), polystyrene (6%), polyvinyl chloride (2%), and polyethylene terephthalate (2%). How plastics were obtained by gulls and the effects on individuals are discussed, as well as environmental considerations about plastic pollution on coastal environments.
Afficher plus [+] Moins [-]A risk based application of the regional model CMAQ to policy decisions Texte intégral
2016
Fisher, Bernard | Chemel, Charles | Sokhi, Ranjeet | Timmis, Roger
A risk based approach to assessing compliance with EU limit values is described, using the advanced chemical transport model CMAQ to determine the regional component of NO2 and particulate matter under various conditions over the UK. A new air quality data analysis retrieval tool AirDART is used to extract concentrations for selected areas of the country. Roadside concentrations in a street canyon are then calculated using a dispersion model. The two model calculations need to be combined to obtain concentrations in future years assuming appropriate changes in emission. To merge the local and regional contributions exactly requires assumptions regarding parameterisations and is computationally expensive. From a risk based viewpoint not every possible condition need be considered in order to make policy decisions. Instead future trends under typical conditions are estimated, allowing the direct effect of local action plans and of national measures to be assessed. The approach is applied to London, this being a worst case UK example, to demonstrate the procedure.
Afficher plus [+] Moins [-]Manganese Removal from Drinking Water Sources Texte intégral
2016
Tobiason, John E. | Bazilio, Arianne | Goodwill, Joseph | Mai, Xuyen | Nguyen, Chuyen
Manganese (Mn) in drinking water can cause aesthetic and operational problems. Mn removal is necessary and often has major implications for treatment train design. This review provides an introduction to Mn occurrence and summarizes historic and recent research on removal mechanisms practiced in drinking water treatment. Manganese is removed by physical, chemical, and biological processes or by a combination of these methods. Although physical and chemical removal processes have been studied for decades, knowledge gaps still exist. The discovery of undesirable by-products when certain oxidants are used in treatment has impacted physical–chemical Mn removal methods. Understanding of the microorganisms present in systems that practice biological Mn removal has increased in the last decade as molecular methods have become more sophisticated, resulting in increasing use of biofiltration for Mn removal. The choice of Mn removal method is very much impacted by overall water chemistry and co-contaminants and must be integrated into the overall water treatment facility design and operation.
Afficher plus [+] Moins [-]Analysis of size-segregated winter season aerosol data from New Delhi, India Texte intégral
2016
Pant, Pallavi | Baker, Stephen J. | Goel, Rahul | Guttikunda, Sarath | Goel, Anubha | Shukla, Anuradha | Harrison, Roy M.
Size distributions of particulate matter and twelve constituent elements were measured at a high traffic site in New Delhi, India during winter 2013. While PM was found to be trimodal, individual elements showed varying size distribution patterns. Three key types of size distributions were observed including unimodal with peaks either in the coarse (Al, Si) or fine (Pb) modes, bimodal with peaks in the fine range (S) and multimodal with peaks in accumulation and coarse (Cu, Sb) modes. Elements such as Al, Si and Fe were found to be in predominantly in the coarse range while Cu, Zn, Pb and Sb were found to be in the fine size range. Two modes dominate the size distribution. One is coarse (ca. 3 μm) and contains mainly crustal elements and hence arises from sources such as soil, road dust, construction dust and possible coal fly ash. The other, more intense mode is fine (ca. 0.6 μm) and appears to comprise sulphate and anthropogenic trace metals which have entered the droplet mode through hygroscopic particle growth in the very high humidity conditions of the Delhi winter. A third, less intensive mode ca. at 0.2 μm probably arises from relatively fresh anthropogenic emissions which have not grown into the droplet mode.
Afficher plus [+] Moins [-]Chemometric techniques in oil classification from oil spill fingerprinting Texte intégral
2016
Ismail, Azimah | Toriman, Mohd Ekhwan | Juahir, Hafizan | Kassim, Azlina Md | Zain, Sharifuddin Md | Ahmad, Wan Kamaruzaman Wan | Wong, Kok Fah | Retnam, Ananthy | Zali, Munirah Abdul | Mokhtar, Mazlin | Yusri, Mohd Ayub
Extended use of GC–FID and GC–MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC–FID and GC–MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.
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