Source Identification and Sedimentary Record of Polycyclic Aromatic Hydrocarbons in Lake Bled (NW Slovenia) Using Stable Carbon Isotopes
ABSTRACT A combination of molecular and stable isotope analyses was used to trace and identify the sources of polycyclic aromatic hydrocarbons (PAH) in sediments of Lake Bled (NW Slovenia). Sediment samples were taken from two locations with contrasting depositional regimes: Zaka Bay, with permanently oxic bottom and station D, where anoxic conditions prevail throughout the year. The concentrations of PAH in surface sediments at the two locations were comparable and higher than in previous studies, reaching 4,230 and 4,380 ng g 1, respectively. It was found that Reten (Re) and Perylene (Per) are both mainly of natural origin in Zaka Bay while, at station D, the value of 13C determined at a depth of 12-14 cm in the 1950s indicated that Re was of pyrolytic origin. The distribution of 13C values of other individual PAH showed that PAH input to lake sediments was of pyrolytic origin, likely dominated by coal and later in 1950s also by wood burning. PAH from vehicular emissions could also contribute to the overall isotope signatures at the depth of 12-14 cm at station D and Zaka Bay corresponding to the period 1953-1961.
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ABSTRACT: Metals are ubiquitous in the environment. The aim of sustainable management of the agro-ecosystem includes ensuring that water continues to fulfill its function in agricultural production, cycling of elements, and as a habitat of numerous organisms. There is no doubt that the influence of large-scale irrigation projects has impacted the regional surface-groundwater interactions in the North China Plain (NCP). Given these concerns, the aim of this study is to evaluate the pollution, identify the sources of trace metals, analyze the influence of surface-groundwater interactions on trace metal distribution, and to propose urgent management strategies for trace metals in the agriculture area in China. Trace metals, hydrochemical indicators (EC, pH, concentrations of Na(+), K(+), Mg(2+), Ca(2+), Cl(-), SO4(2-), and HCO3(-)) and stable isotopic composition (δ(18)O and δ(2)H) were determined for surface water (SW) and groundwater (GW) samples. Trace metals were detected in all samples. Concentrations of Fe, Se, B, Mn, and Zn in SW exceeded drinking water standards by 14.8%, 29.6%, 25.9%, 11.1%, and 14.8% higher, respectively, and by 3.8%, 23.1%, 11.5%, 11.5%, and 7.7% in GW. The pollution of trace metals in surface water was more serious than that in groundwater, and was also higher than in common irrigation areas in NCP. Trace metals were found to have a combined origin of geogenic and agriculture and industrial activities. Their distribution varied greatly and exhibited a certain relationship with the water flow direction, with the exception of a number of singular sites. Hydrochemical and environmental isotopic evidence indicates surface-groundwater interactions influence the spatial distribution of trace metal in the study area. Facing the ongoing serious pollution, management practices for source control, improved control technologies, and the construction of a monitoring net to warn of increased risk are urgently needed.Science of The Total Environment 12/2013; 472C:979-988. DOI:10.1016/j.scitotenv.2013.11.120 · 3.16 Impact Factor
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ABSTRACT: The extraction of bitumen from the Alberta oil sands using in-situ technologies is expanding at a rapid rate; however, investigations into the environmental impacts of oil sands development have focused on surface mining in the Athabasca region. We measured polycyclic aromatic hydrocarbons (PAH) in soils, spruce needles, and lake sediment cores in the Cold Lake oil sands region to provide a historical and spatial perspective on PAH contamination related to in-situ extraction activities. A pronounced increase in PAH concentrations was recorded in one of two study lakes (Hilda Lake) corresponding to the onset of commercial bitumen production in ∼1985. Distance from extraction rigs was not an important predictor of PAH concentrations in soils, although two samples located near installations were elevated in alkyl PAHs. Evidence of localized PAH contamination in Hilda Lake and two soil samples suggests that continued environmental monitoring is justified to assess PAH contamination as development intensifies.Environmental Pollution 08/2013; 182C:307-315. DOI:10.1016/j.envpol.2013.07.012 · 3.73 Impact Factor
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ABSTRACT: Analyses of sediment core samples are primary sources of historical pollution trends in aquatic systems. Determining organic compounds, such as POPs, in the dated sediments enables the estimation of their temporal concentration changes and the identification of the contaminant origin in local regions. Wars, large-scale fires, economical transitions, and bans on certain chemicals are reflected in the sediment organic compound concentrations. The high POP concentrations in surficial sediments suggest that these chemicals, even after being banned, remain in the environment. Furthermore, vertical profiles can help in understanding the sedimentation process and in estimating effective countermeasures against pollution. Moreover, studies published during the period 1991-2013 on PAHs, PCBs, OCPs, dioxins and dioxin-like compound concentrations in sediment core samples are reviewed.Marine Pollution Bulletin 11/2013; 78(1-2). DOI:10.1016/j.marpolbul.2013.11.008 · 2.79 Impact Factor