Concentrations, distributions, and sources of polychlorinated biphenyls and polycyclic aromatic hydrocarbons in bed sediments of the water reservoirs in Slovakia

Abstract

Dredging water reservoirs is necessary to maintain accumulation capacity and to prevent floodings. As a first step, the quality of the bed sediments in water reservoirs must be determined before dredging operations. In this study, sediment samples from 34 stations of three selected water reservoirs (Zemplinska Sirava, Velke Kozmalovce, and Ruzin) were collected to investigate concentrations, distributions, and hazards of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and to predict their possible sources. Total PCB concentrations were in the range of 20.4 to 2,325 ng/g. The maximum concentrations of PCBs were found in sediments from Zemplinska Sirava, which is in the vicinity of a former manufacturer of PCBs. The composition of PCBs was characterized by tri- and hexa-CB congeners, indicating the influence of contamination from the use of specific Delor mixtures, formerly produced and massively used on the territory of Slovakia. The data showed that the highest total PAH concentrations were associated with the sediments from the Velke Kozmalovce, ranging from 7,910 to 29,538 ng/g. On the other hand, the lowest total PAH concentrations (84-631 ng/g of dry weight) were found in the sediments of Zemplinska Sirava, an important recreational area in eastern Slovakia. The distribution of individual PAHs was similar among the three water reservoirs, and this, together with principal component analysis and diagnostic PAH ratios, suggests mainly pyrolytic contamination of the sediments. However, petrogenic inputs appear to be important in the Zemplinska Sirava sediments.

Distribution, source, and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Hun River, northeast China

“…The table shows that the levels of ∑PAHs in the sediments from the upstream section of the Hun River and the Dahuofang Reservoir in this study were comparable to those detected in most of the major rivers in China, such as the Pearl River Estuary (Luo et al 2006), Qiantang River (Zhu et al 2008), Huaihe River (Feng et al 2012), Xiangjiang River (Zhang et al 2013b), and Lijiang River (Xue et al 2013). They were also comparable to reported results for other rivers and reservoirs around the world, such as Zemplinska sirava Reservoir in Slovakia (Hiller et al 2011) and Ibirité Reservoir in Brazil (Mozeto et al 2014) but were significantly lower than those found in contaminated and industrialized regions, such as the Wuhan section of the Yangtze River (Feng et al 2007), Haihe River (Jiang et al 2007), Liangtan River (Liu et al 2013), Beijiang River (Song et al 2014), Iko River estuary in Nigeria (Essien et al 2011), Ruzin Reservoir and Velke kozmalovce Reservoir in Slovakia (Hiller et al 2011), Ammer River in Germany (Liu et al 2013), and Huveaune River in France (Kanzari et al 2014). In contrast, the PAH concentrations in the downstream section of the Hun River were higher than for most of the abovementioned sites (Table 2).…”

“…Most have been found to be mutagenic, carcinogenic, and teratogenic, and 16 PAHs have been listed as priority pollutants by the US EPA (Haritash and Kaushik 2009;Hiller et al 2011). PAHs are generally introduced into the environment via anthropogenic activities, including incomplete combustion of organic matter, oil leakages, traffic-related emissions, sewage discharges, etc.…”

Radial Distribution of Stars, Gas, and Dust in Sings Galaxies. Ii. Derived Dust Properties

“…Although the smallest grains can undergo extreme temperature changes in small periods of time, large ones dominating the FIR emission can be considered to have reasonably steady temperatures T ≈ 17U 1/6 K (DL07). As a sanity check, for NGC 7331 we obtain a roughly flat profile with U min ≈ 2.5, implying T ≈ 20 K, the same value found by Thilker et al (2007) when applying a double blackbody fit. By analyzing the IR SEDs of different regions in M 81, Pérez-González et al (2006) found that the temperature of the cold component varies from ≈22 K in the central regions to ≈15 K at 10 kpc from the center, which is consistent with our U min profile ranging from 5 to 0.7 in the same relative radial range.…”

“…The radial decrease of the star formation efficiency found in nearby spirals (Thilker et al 2007;Leroy et al 2008) could also partly explain the low dust-to-gas ratios seen in Figure 16. The presence of large reservoirs of gas which has not been yet transformed into stars (and hence into dust) would drop the dust-to-gas ratio in the outer regions of these galaxies.…”

Enhanced host–guest electrochemical recognition of herbicide MCPA using a β-cyclodextrin carbon nanotube sensor

“…MCPA is not extensively metabolised and urine is the predominant route of excretion [12]. Although MCPA is only a moderately toxic herbicide, monitoring its residues in water and soil is crucial because it can influence the nervous system upon adsorption through the skin and its prolonged inhalation can cause dizziness, burning in the chest and coughing [13].…”