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Τετάρτη 5 Ιουνίου 2019

Environmental Monitoring and Assessment

Distribution, toxicity, and origins of polycyclic aromatic hydrocarbons in soils in Ulsan, South Korea

Abstract

This study was conducted to investigate the concentrations, distributions, toxicities, and sources of polycyclic aromatic hydrocarbons (PAHs) in the soils from different areas in Ulsan, South Korea. Samples were collected from 41 sites, including a waste treatment facilities area (WA), traffic facilities area (TA), child playground area (CA), industrial area (IA), railroad facilities area (RA), ore and iron scraps fields area (OA), and residential area (ReA). Ulsan was chosen for research area because it used to be an environmental hot spot in South Korea, and 16 PAHs in the US EPA priority pollutant list were selected. The concentration of total PAHs (t-PAHs) ranged from 61.7 to 12,421 μg/kg, and the average concentration of t-PAHs was 706.9 μg/kg. The distribution of PAHs by ring number indicated that the portion followed the order of 4 rings > 5 rings > 3 rings > 6 rings > 2 rings. According to PAH origin indices, LMW/HMW (low molecular weight 2–3 ring PAHs over high molecular weight 4–6-ring PAHs), phenanthrene/anthracene ratio and fluoranthene/pyrene ratio, benzo(g,h,i)perylene/indeno (1,2,3-c,d)pyrene ratio, vehicular emissions, and the combustion of fossil fuel were the sources of PAHs. The strong correlation (R2 = 0.995) between t-PAHs and total carcinogenic PAHs (t-PAHcarc) indicated that the concentration of t-PAHcarc increased in proportion with that of t-PAHs. The toxic equivalent concentrations (TEQs) of PAHs in the soils ranged from 44.0 to 1929.9 μg TEQ/kg. It is imperative to set regulatory levels for PAHs for periodic monitoring and rapid remediation action of contaminated soils, because there are no national standards in South Korea for 15 PAHs with the exception of benzo(a)pyrene.



Inhomogeneity of sediment samples in analysis of hexabromocyclododecane

Abstract

The repeatability test of the analytical method for hexabromocyclododecane (HBCD) was conducted with sediment sample. The maximum HBCD concentration exceeded the minimum by a factor of 90 even though the identical sediment samples were used. Therefore, we examined which step of the analytical method was the factor causing variability. We examined the blank test, and confirmation test of the extraction and purified procedure. From these results, we confirmed that there was nothing wrong with the accuracy of our analytical method. These results indicate that the variability of HBCD concentration in the repeatability test was attributed not to the analytical method, but to the inhomogeneity of the sediment sample. Aluminum, silicon, and organic carbon in sediments were measured to compare the variability of these concentrations with that of HBCD concentration. These concentrations were similar values within identical samples which showed variability in HBCD concentration. HBCD concentration in several samples did not correlate with organic carbon content. These results suggests that sediment samples were homogeneous by itself, and HBCD was heterogeneously distributed in spite of homogeneity of organic carbon in sediment. The sediment sample with variability in HBCD concentration showed different HBCD diastereomer compositions in identical sediment. It implies that the sample contained HBCD derived from different histories or point sources. Even though we increased sample amounts to analyze the homogeneity of the sample, HBCD concentration varied within identical samples if the sample had a hot spot. Past monitoring data may contain overestimation or underestimation of HBCD concentration in sediment.



Heavy metal accumulation in surface sediments of the Ganga River (India): speciation, fractionation, toxicity, and risk assessment

Abstract

We investigated the distribution of different fractions of eight heavy metals (Zn, Cr, Cu, Pb, Cd, Ni, Fe, and Mn) in the bed sediment of the Ganga River. The study was conducted during summer low flow (March to June 2017) considering a 285-km middle stretch of the Ganga River between the Allahabad upstream and the Varanasi downstream. To assess the metal levels from a toxicological perspective, we tested the relationships between metals and sediment microbial/extracellular enzyme activities. Most of the metals showed a large fraction in residual form. However, Zn, Pb, and Cd showed about 20–30% share in the exchangeable form. The total metal concentration poorly reflected the toxicity but the exchangeable fractions did show strong negative correlations (r = − 0.83 to − 0.63; p < 0.01) with microbial/enzyme activities. Also, the nutrients and organic carbon showed strong positive correlations (r = 0.62 to 0.89; p < 0.001) with microbial/enzyme activity. The phosphate showed a strong negative correlation (r = −0.82; p < 0.001) with alkaline phosphatase. The principal component analysis (PCA) and the indices such as contamination factor (CF), enrichment factor (EF), pollution load index (PLI), geoaccumulation index (Igeo), and risk assessment code (RAC) revealed moderate to severe contamination with strong anthropogenic influence. As per the United States Environmental Protection Agency, the metal concentrations at many locations were in the highly toxic range. The study has relevance from a toxicological perspective and for the management of the Ganga River.



Spatial distribution and ecological risk assessment of trace metals in surface sediments of Lake Qaroun, Egypt

Abstract

A suite of trace metals was determined in twenty surface sediments collected from Lake Qaroun, which is designated as a natural reserve in 1989 to examine their spatial distribution and their potential environmental impact on the lake. Contamination factor (Cf), enrichment factor (EF), geoaccumulation index (Igeo), and pollution load index (PLI) are applied to evaluate the quality of the lake. The highest concentrations were detected in the eastern portion of the lake near Al-Bats drain. The levels of Ba exceeded the toxicity reference value (TRV) (20 ng/g dw) set by US EPA for all sediments, while sediments collected from Al-Bats region exceeded the TRV for Zn (68 ng/g dw). Arsenic, Ba, Sn, Co, Cu, and Hg are poorly correlated with background value of Fe suggesting anthropogenic activities over the entire lake. The values of Cf and Igeo confirmed that the eastern portion of the lake has been found moderately to considerably contaminated by As, Sn, and Zn. Sediments collected from the eastern location (S1) were very highly enriched of Sn (22.47); however, the other eastern locations were highly enriched of Sn, As, Cd, Co, and Ba. It is clear that sites near Al-Bats and El-Wadi drains are hot spots, which got immense amounts of domestic, agricultural, and industrial wastes. Behind the influence of these discharges, concentrations are decreased. The PLI over the entire lake ranged from 0.247 to 0.801 for all sites, which reflect unpolluted status.



Demand prediction and regulation zoning of urban-industrial land: Evidence from Beijing-Tianjin-Hebei Urban Agglomeration, China

Abstract

As a main type of urban construction land, urban-industrial land is used to provide the judging criteria for construction land scale in the planning period when urban population, industrial development, investment scale, and other conditions are uncertain in China; however, research on expected indicator such as urban-industrial land in overall land use plan mainly focuses on qualitative analysis; quantitative analysis research has not yet been carried out. Using MATLAB R2016a software modeling tools to establish GM (1, 1) model and RBF neural network model, respectively, this paper predicted the demand of urban-industrial land in Beijing-Tianjin-Hebei Urban Agglomeration. Comparing the predicated results with the actual value of urban-industrial land in Beijing, Tianjin, and 11 prefecture-level cities in Hebei Province, we determined the reasonable prediction model for urban-industrial land after testing the accuracy of the two prediction models. The results showed that the RBF neural network model was the more reasonable prediction model for urban-industrial land. Using the predicted results of the RBF neural network model, combining expected indicators of overall land use plan (2006–2020) in Beijing and Tianjin, as well as 11 prefecture-level cities in Hebei Province in the planning target year, determined remaining usable time of urban-industrial land. Finally, combined with the actual scale of urban-industrial land in 2015 and the predicated scale of urban-industrial land in 2020, the remaining usable time of each city's urban-industrial land was calculated in terms of the average annual growth rate of urban-industrial land from 2009 to 2015. According to the comparative relationship between the remaining usable time and the remaining time of the overall land use plan (5 years), urban-industrial lands were divided into three kinds of regulation zones: reasonable reduction zone, optimized adjustment zone, and core development zone. The policy implications for urban-industrial land in each regulation zone were also provided. This paper can provide reference for regulation zoning of urban-industrial land in developing countries and regions.



Optimization and validation of headspace solid-phase microextraction method coupled with gas chromatography–triple quadrupole tandem mass spectrometry for simultaneous determination of volatile and semi-volatile organic compounds in coking wastewater treatment plant

Abstract

Industrial wastewater could be an important source for the emission of volatile (VOCs) and semi-volatile organic compounds (SVOCs), but little is known about it. In this study, a method for the identification and quantitation of 43 VOCs and SVOCs in coking wastewater was developed using a solvent-free equilibrium extraction method on the basis of headspace solid-phase microextraction accompanied by gas chromatography–triple quadrupole tandem mass spectrometry (HS-SPME-GC-MS/MS). To ensure good extraction efficiency, the parameters that have an effect on the HS-SPME-GC-MS/MS process were carefully optimized, in terms of fiber exposure time and temperature, pH, salt additives, sample volume, and desorption time. The HS-SPME method showed good linearity range with coefficients of determination (R2) ≥ 0.991 and achieving a satisfactory recoveries value (70–120%) with good relative standard deviations (RSDs) < 20% (precision). Furthermore, the purposed approach proved to be sensitive with low detection limits, where the values ranged from 0.03 to 3.01 μg/L. The real sample analysis result showed that 43 of VOCs and SVOCs were detected in raw coking wastewater, with 3-cresol as the dominant ones. Further, the method revealed that seven phenols, 11 polycyclic aromatic hydrocarbons, and five BTEX were detected even in the treated effluent. In conclusion, the HS-SPME method developed in this study is simple in sample preparation, convenient, sensitive, and could satisfy the requirement of the analysis of VOCs and SVOCs in coking wastewater.



Aquatic insect communities in small stream in the south of Brazil

Abstract

Pollution of rivers and streams, by anthropic action, is characterized as an environmental, social, and sanitary problem. Factors such as the association between the marginal vegetation, the distribution of the substrates in the riverbed, and the availability of allochthonous organic matter influence the distribution and composition of the aquatic entomofauna. The objective of this study was to analyze the structure of aquatic insect communities in a pasture stream in northern Paraná, southern Brazil, with emphasis on the groups of indicators of good water quality, thus inferring the conditions of its preservation. Samples were collected from July to October in three parts of the stream (P1, P2, and P3), where the insect faune was collected with the aid of a sieve in the foliage substrate and washing of rocks and decomposing pieces of wood. A total of 1323 individuals were collected, being Chironomidae (Diptera) the most abundant taxon. The analysis of the biotic indices (EPT/Chironomidae, IBF, BMWP, and BMWP/ASPT) and diversity indicated better preservation conditions at points P1 and P3 where the riparian forest was well preserved, with less exposure to the stream bed. In P2, the entomofauna presented less diversity and the biotic indexes indicated loss of water quality, showing the impacts of changes in the marginal vegetation of this section. In a generally preserved aquatic environment, small changes in its vegetation are sufficient to cause an imbalance in the aquatic insect community, showing the efficiency of these organisms as bio-indicators and the sensitivity of biotic indexes.



Investigating the effect of several factors on concentrations of bioaerosols in a well-ventilated hospital environment

Abstract

This study characterized and quantified the bacterial and fungal bioaerosols in nine wards of the Razavi Hospital (Mashhad, Iran) that is equipped with an advanced heating, ventilating, and air conditioning (HVAC) system including HEPA filters for air cleaning. In this study, 432 samples were taken from the indoor air of multiple hospital wards during the morning and afternoon shifts during summer and autumn. The particle number concentrations with sizes of > 0.3, > 0.5, > 1, > 2, > 5, and > 10 μm were measured using a 6-channel handheld particle counter. A greater diversity of bioaerosol types were observed during the morning shifts and during summer. The microbial load was not affected significantly by the temperature, relative humidity, working shift, season, and number of visitors, indicating the effectiveness of a well-designed ventilation system to eliminate site-specific variations. For microbial number concentrations, a significant correlation was only observed between the number of particles with a diameter of > 10 μm and the airborne microbial loading. Thus, passive sampling may not properly reflect the actual concentrations of smaller bioaerosols. In conclusion, HEPA filters in the HVAC system successfully decreased the bioaerosol concentrations in the hospital environment. Additionally, we recommend that active sampling be used in cases where a well-functioning HVAC system exists.



EventFinder: a program for screening remotely captured images

Abstract

Camera traps are becoming ubiquitous tools for ecologists. While easily deployed, they require human time to organize, review, and classify images including sequences of images of the same individual, and non-target images triggered by environmental conditions. For such cases, we developed an automated computer program, named EventFinder, to reduce operator time by pre-processing and classifying images using background subtraction techniques and color histogram comparisons. We tested the accuracy of the program against images previously classified by a human operator. The automated classification, on average, reduced the data requiring human input by 90.8% with an accuracy of 96.1%, and produced a false positive rate of only 3.4%. Thus, EventFinder provides an efficient method for reducing the time for human operators to review and classify images making camera trap projects, which compile a large number of images, less costly to process. Our testing process used medium to large animals, but will also work with smaller animals, provided their images occupy a sufficient area of the frame. While our discussion focuses on camera trap image reduction, we also discuss how EventFinder might be used in conjunction with other software developments for managing camera trap data.



A phytotoxic impact of phenolic compounds in olive oil mill wastewater on fenugreek " Trigonella foenum-graecum "

Abstract

The objective of this study is the determination of the chemical structure of nine phenolic molecules responsible for the phytotoxic action on the germination of the plant species "Trigonella foenum-graecum". The phytotoxic action was evaluated by calculating the germination index of the plant species for a period of 5 days of incubation. The analysis of the physicochemical properties of phenolic molecules shows that hydrophobicity is a key factor in phytotoxicity. The sublethal concentration varies as follows: hydroquinone (0.91 mM), 4-aminophenol (0.85 mM), phenol (0.75 mM), gallic acid (0.59 mM), caffeic acid (0.56 mM), 3,5-di-tert-butylcatechol (0,45 mM), quercetin (0.33 mM), oleuropein (0.3 mM), and catechol (0.13 mM). Phytotoxicity varies depending on the nature and position of the substituents on the aromatic ring. The reactivity of this type of molecule is partly linked to the presence of catechol function that can play the main role in phytotoxicity of the Fenugreek.



Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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