Sorption of polycyclic aromatic hydrocarbons (PAHs) to carbonaceous materials in a river floodplain soil

We report on sorption isotherm of phenanthrene (Phe) for river floodplain soil associated with carbonaceous materials, with particular attention being devoted to the natural loading of Phe. Our sorption experiments with original soil samples, size, and density sub-fractions showed that the light fraction had the highest sorption capacity comparable to low rank coals. In addition, the light fraction contributed most for the sorption of Phe in total soil samples. K(oc) values for all fractions were in the same range, thus indicating that coal and coal-derived particles in all samples are responsible for the enhanced sorption for Phe. Sorption was strongly nonlinear and the combined partitioni…

Identification of carbonaceous geosorbents for PAHs by organic petrography in river floodplain soils.

Organic petrographic analysis was applied to provide direct information on carbonaceous geosorbents for PAHs in river floodplain soils. The anthropogenic OM group (primarily coal and coal-derived particles) displayed large volume amounts for all the soil samples. Distinct PAH concentrations with similar PAH distribution patterns were determined in grain size and density fractions for each sample. Two-ring PAHs had stronger correlation to organic carbon (OC) than black carbon (BC) contents, while heavier PAHs showed correlation to BC, rather than OC. In this study, we combined grain size and density separation, PAH determinations, TOC and BC measurements, and organic petrographic identificat…

Kolloide: Die Welt der vernachlässigten Dimensionen

Aquatische Kolloide sind in allen naturlichen Gewassern vorhanden. Sie umfassen anorganische Kolloide wie Tonminerale, organische Kolloide wie Huminstoffe, Mikroorganismen und anthropogen eingetragene Kolloide wie Rus oder Platin aus Katalysatoren. Kolloide konnen hydrophobe organische Schadstoffe sorbieren und transportieren oder nachteilig die Wasserqualitat beeinflussen (z.B. pathogene Keime). Sie konnen die Leistung von Brunnen durch Verblockung der Porenraume im Grundwasser mindern. Kolloide konnen jedoch auch zur Sanierung von Grundwasserschadensfallen eingesetzt (Tenside) oder in der Wasseraufbereitung verwendet werden (Flockungsmittel, Katalysatoren). Kolloide entstehen oder werden …

Vertical Distribution and Speciation of Trace Metals in Weathering Flotation Residues of a Zinc/Lead Sulfide Mine

Sulfide-bearing mine tailings are a serious environmental problem around the world. In this study, the vertical distribution and speciation of Zn and Pb in the fine-grained flotation residues of a former sulfide ore mine in Germany were investigated to assess the inorganic weathering processes that effect the environmental risk arising from this site. Total metal contents were determined by X-ray fluorescence spectroscopy (XRF). Mobilizable fractions of Zn, Pb, Fe, and Mn were quantified by sequential chemical extractions (SCE). Furthermore, the speciation of Zn was analyzed by Zn K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) to identify the residual Zn species. The v…

HCHs and DDTs in sediment-dwelling animals from the Yangtze Estuary, China

HCHs and DDTs in sediment-dwelling animals including mollusks and crabs from the Yangtze Estuary were deter- mined by GC-ECD. Levels of t-HCH were in the range of 1.2-5.5 ng g � 1 and averaged 3.5 ng g � 1 in mollusks, while t-DDT concentrations ranged from 26.0 to 68.8 ng g � 1 , with a mean of 34.5 ng g � 1 . In crabs t-HCH concentrations var- ied from 2.0 to 25.7 ng g � 1 and averaged 13.8 ng g � 1 , whereas the concentrations of t-DDT were in the range of 1.5- 24.8 ng g � 1 with a mean value of 5.9 ng g � 1 . The HCHs and DDTs levels depend on geographical position and sources, showing the high levels at fresh water area in the estuary, such as XP, CM and LHK sites, and lower at brackis…

Characterization and source identification of polycyclic aromatic hydrocarbons (PAHs) in river bank soils.

Elevated PAH concentrations were detected in bank soils along the Mosel and Saar Rivers in Germany. Information on the identification of PAH sources in this area however remains unclear. This study was able to characterize the PAH sources by application of several approaches, including consideration of the distribution patterns of 45 PAHs (including 16 EPA PAHs and some alkyl PAHs), specific PAH ratios, distribution patterns of n-alkanes and principal component analysis (PCA). In addition, the efficiency of the tested approaches was assessed. The results from the application of the various source identification methods showed that pyrogenic PAHs dominate soil samples collected upstream of t…

Aquatische Kolloide: Kleine Teilchen - große Wirkung

Geloste naturliche und anthropogene (Schad-)Stoffe verandern die Zusammensetzung eines unserer Hauptnahrungsmittel, des Trinkwassers. Weniger bekannt ist jedoch, dass in jedem aquatischen Milieu auch mobile Feststoffe (Kolloide) die Wasserqualitat beeinflussen. Schatzt man den Transport von Bio-Kolloiden falsch ein, kann dies zu einer unmittelbaren Gefahrdung des Trinkwassers fuhren.

Occurrence of coal and coal-derived particle-bound polycyclic aromatic hydrocarbons (PAHs) in a river floodplain soil.

A PAH contaminated river floodplain soil was separated according to grain size and density. Coal and coal-derived particles from coal mining, coal industry and coal transportation activities were identified by organic petrographic analysis in our samples. Distinct concentrations of PAHs were found in different grain size and density fractions, however, similar distribution patterns of PAHs indicated similar sources. In addition, although light fractions had the mass fraction by weight of less than 5%, they contributed almost 75% of the total PAHs in the soil. PAH concentrations of all sub fractions showed positive correlation with their TOC contents. Altogether, coal and coal-derived partic…

The German Water Chemical Society: Actual Trends and Fields of Research in the Principle Committee “Basic Research”Representing the principle committee “Basic Research” of the German Water Chemical Society — Division of the German Chemical Society.

Methods of metal release assessment in soil water at anoxic sites

Department of Geology, Vienna University, Vienna, Austria Metal mobility at contaminated sites can be assessed by soil water investigations or by leaching tests. Leaching tests are usually carried out in open contact with the atmosphere disregarding possible changes of redox conditions. This can affect the original metal speciation and distribution, particularly when anoxic samples are investigated. In this study, the applicability of common leaching tests (the German S4 test (S4), ammonium nitrate extraction (AmmN), and saturation soil extraction (SSE)) is tested for the assessment of zinc release from sulfide-bearing flotation residues of a former ore mine. Results are compared to soil so…

Elevated polycyclic aromatic hydrocarbons in a river floodplain soil due to coal mining activities

Elevated PAH concentrations were found in soil samples collected along the Mosel River. These contaminations were associated with the occurrence of coal particles found in the soil. The majority of the PAH contamination in the soils was linked to coal mining activities in the Saar region. Density and grain size separation showed a similar PAH distribution pattern in all of the fractions, indicating a uniform origin of PAHs. Together with coal petrography a good correlation between TOC and PAHs concentration confirmed the impact of former coal mining activity on the PAHs distribution in study area.