Determination of selected quaternary ammonium compounds by liquid chromatography with mass spectrometry. Part II. Application to sediment and sludge samples in Austria

Soxhlet extraction and high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry detection (MS/MS) was used for the determination of selected quaternary ammonium compounds (QACs) in solid samples. The method was applied for the determination of alkyl benzyl, dialkyl and trialkyl quaternary ammonium compounds in sediment and sludge samples in Austria. The overall method quantification limits range from 0.6 to 3 microg/kg for sediments and from 2 to 5 microg/kg for sewage sludges. Mean recoveries between 67% and 95% are achieved. In general sediments were especially contaminated by C12 chain benzalkonium chloride (BAC-C12) as well as by the long C-chain dialkyldimethylammonium chloride (DDAC-C18) with a maximum concentration of 3.6 mg/kg and 2.1mg/kg, respectively. Maxima of 27 mg/kg for DDAC-C10, 25 mg/kg for BAC-C12 and 23 mg/kg for BAC-C14 were determined for sludge samples. The sums of the 12 selected target compounds range from 22 mg/kg to 103 mg/kg in the sludge samples.     

High concern chemicals in top layer sediments of the northern Adriatic seabed as markers of old waste dumpings

The results are presented of a survey planned to assess the presence of high concern chemicals in sediments collected in a northern sector of the Adriatic sea neighboring the Venice lagoon. For the assessment, persistent marker chemicals were selected from the families of polycyclic aromatic hydrocarbons, polychlorobiphenyls, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and chlorinated pesticides. Based on the chemical-specific concentrations and PCDD+PCDF profiles determined in the sediments analyzed, dumping zones appear to have existed approximately 5-6km away from lagoon shoreline. Contamination levels exceed the quality criteria established by the pertinent Italian national regulation at many sampling sites, eventually reflecting ("fingerprinting") industrial activities once performed in the industrial settlement of Porto Marghera within the Venice lagoon. In coastal samples, concentration levels appear to be lower than those determined at offshore sampling sites.     

Assessment of Allowable Thermal Load for a River Reservoir Subject to Multi-Source Thermal Discharge from Operating and Designed Beloyarsk NPP Units (South Ural,Russian Federation)

This study develops a quantitative approach to the establishment of a maximum allowable thermal discharge into a freshwater body (the Beloyarsk Reservoir) incorporated in the once-through cooling technology at the Beloyarsk nuclear power plant (NPP) (South Urals, Russian Federation). The study is based on a 3-D hydrodynamic model, embracing water circulation, heat transfer, and ice-cover formation in the Beloyarsk Reservoir. The model is driven by atmospheric forcing, river runoff, and the discharge/intake of NPP cooling water. It was used to simulate the horizontal and vertical distribution of water temperature under the effect of the operation of existing (number 3) and anticipated (numbers 4 and 5) nuclear power units. The model is validated by the comparison of the computation results with observed water temperature distribution and ice-cover configuration obtained with remote sensing techniques. The model was also used to predict the future evolution of water temperature after the launching of two new power units, which, having a common cooling system, may affect each other. It was shown that the first of the new units, no. 4, will not dramatically affect the existing thermal conditions in the reservoir, while launching one more unit, no. 5, will apparently result in overheating of the reservoir water in response to the greater volume of cooling-water discharge from the two power units. Because of a specific configuration of the recirculation flow, the reservoir may fail to cope with the dissipation of the generated heat, leading to a steady (uncontrolled) rise of water temperature in the inlet channel to one of the power units. This will reduce the potential of NPP, using the once-through cooling technology, and will most likely have an adverse effect on the survival of aquatic organisms in the Beloyarsk Reservoir. Therefore, some other environment-saving technologies must be developed for removing surplus heat from the unit no. 5 of the Beloyarsk NPP.     

Spatio-temporal analyses of cropland degradation in the irrigated lowlands of Uzbekistan using remote-sensing and logistic regression modeling

Advancing land degradation in the irrigated areas of Central Asia hinders sustainable development of this predominantly agricultural region. To support decisions on mitigating cropland degradation, this study combines linear trend analysis and spatial logistic regression modeling to expose a land degradation trend in the Khorezm region, Uzbekistan, and to analyze the causes. Time series of the 250-m MODIS NDVI, summed over the growing seasons of 2000–2010, were used to derive areas with an apparent negative vegetation trend; this was interpreted as an indicator of land degradation. About one third (161,000 ha) of the region’s area experienced negative trends of different magnitude. The vegetation decline was particularly evident on the low-fertility lands bordering on the natural sandy desert, suggesting that these areas should be prioritized in mitigation planning. The results of logistic modeling indicate that the spatial pattern of the observed trend is mainly associated with the level of the groundwater table (odds?=?330 %), land-use intensity (odds?=?103 %), low soil quality (odds?=?49 %), slope (odds?=?29 %), and salinity of the groundwater (odds?=?26 %). Areas, threatened by land degradation, were mapped by fitting the estimated model parameters to available data. The elaborated approach, combining remote-sensing and GIS, can form the basis for developing a common tool for monitoring land degradation trends in irrigated croplands of Central Asia.     

Genotoxic and cytotoxic effects of pethoxamid herbicide on Allium cepa cells and its molecular docking studies to unravel genotoxicity mechanism

Environmental Science and Pollution Research - Pethoxamid is chloroacetamide herbicide. Pethoxamid is commonly used to kill different weeds in various crops. Pethoxamid can leach in the water and...     

Correction to: Genotoxic and cytotoxic effects of pethoxamid herbicide on Allium cepa cells and its molecular docking studies to unravel genotoxicity mechanism

Environmental Science and Pollution Research -     

A Stereoselective Route to R-(+)-Limonene-Based Non-isocyanate Poly(hydroxyurethanes)

Journal of Polymers and the Environment - Bio-based non-isocyanate poly(hydroxyurethanes) (NIPUs) have recently gained significant interest due to increasing awareness of the health and...