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Abstract

Alien Mediterranean mussels Mytilus galloprovincialis, Pacific oysters Crassostrea gigas and indigenous Cape mussels Choromytilus meridionalis were used as sentinel biomonitors of inorganic pollutants in Saldanha Bay, South Africa. Neutron activation analysis was used to determine the concentrations of 33 macro and microelements in the soft tissues of molluscs. The Mediterranean mussels significantly demonstrated the higher accumulation ability to S, Se and Br than the Pacific oysters, whereas the Pacific oysters - to Fe, Cu, Zn and As. The Cape mussels are more sensitive to Mn and As and the Mediterranean mussels were sensitive to Zn and Se.

Abstract

The paper analyses the intensity changes of three pollution parameter vectors in space and time. The RGB raster pollution data of the Lithuanian territory used for the research were prepared according to the digital images of the Sentinel-2 Earth satellites. The numerical vectors of environmental pollution parameters CH4 (methane), NO2 (nitrogen dioxide) and for direct comparison O2 (oxygen gas) were used for the calculations. The covariance function theory was used to perform the analysis of intensity changes in digital vectors. Estimates of the covariance functions of the numerical vectors of pollution parameters and O2 or the auto-covariance functions of single vectors are calculated from random functions consisting of arrays of measurement parameters of all parameters vectors. Correlation between parameters vectors depends on the density of parameters and their structure. Estimates of covariance functions were calculated by changing the quantization interval on a time scale and using a compiled computer program using the Matlab procedure package. The probability dependence between the environmental pollution parameter vectors and trace gas of the territory in Lithuania and their change in time scale was determined.

Abstract

Chemical-looping combustion (CLC) is an attractive process in CO2 capture, especially when solid oxygen carriers are used in it. The main requirements for oxygen-transporting materials include appropriate oxidation (in air) and reduction (in the presence of fuel) ability. In the paper a conceptual proposition for CLC-related processes with the application of solid oxygen carriers oxidized in both air and CO2 atmosphere has been presented. The possibility of the “looping” process on the same carriers using both CO2 and air atmosphere as an oxidizing agent allows us to enrich the concept of CLC and related processes by proposing a cyclic recirculation of the produced CO2 back to the installation. The oxidizing of solid oxygen carrier in a CO2 atmosphere is accompanied by CO emission from the plant. This toxic gas could be transformed into a useful product in any chemical process. It is possible to combine the looping processes with manufacturing of any appropriate morphological form of carbon in the cyclic CO disproportionation process. The combined process could lead to a lower CO2 emissions to the environment. SrTiO3 doped by Cr (STO:Cr) and a mixture of TiO2- and Ni-based compounds (TiO2-Ni) were investigated as oxygen transporting materials. The experiment methodology based on thermogravimetric, diffraction and spectroscopic studies was shown. Thermogravimetric (TGA) and Powder Diffraction (XRD) measurements were provided in-situ during a few cycles in a reducing (Ar+3 % H2) and oxidizing environment. Moreover, the STO:Cr powders were characterized ex-situ by the X-ray Photoelectron Spectroscopy (XPS) method. It was found that in tested conditions the cyclic process of the investigated powders’ oxidation and reduction is possible. Satisfactory results considering the oxygen transport capacity was obtained for the TiO2-Ni sample.

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are a common part of the environment where they come from burning fossil fuels (through an incomplete combustion process). From a toxicological point of view, PAHs are considered to be carcinogens with a mutagenic and teratogenic effect. On the other hand, ferrates are generally believed to be the ideal chemical agent for water treatment due to their strong oxidation potential. Herein, the efficiency of degradation of PAHs (with the special emphasis on B[a]P) by ferrates under laboratory conditions was studied. The formation of degradation products was also considered. For this, two types of ferrates were used and both of them efficiently degraded B[a]P. When comparing ferrates that were bought from a Czech and USA company, no significant changes in terms of B[a]P degradability were observed. It was determined that the degradation efficiency of PAHs by ferrates was dependent on their molecular weight. Two and three cyclic PAHs have been completely degraded within 30 minutes, whereas five (and more) cyclic PAHs, only partially. The results obtained with ferrates were compared to the ones obtained with a classical oxidizing agent - KMnO4. In a qualitative test to detect degradation products of PAHs, two were identified, namely fluoren-9-one derived from fluorene and acentaphthylene, formed from acenaphthene.

Abstract

As carrot seeds are notoriously slow to germinate and are often irregular in breaking dormancy, new methods of stimulation are still sought. This study examines for the first time the effect of an algal extract and static magnetic field (SMF) and their synergistic effect on carrot seeds germination. The algal extract, produced from freshwater macroalgae - Cladophora glomerata, was used directly to the paper substrate at a dose of 20, 40, 60, 80 and 100 %. The exposure of seeds to the magnetic field (500 mT and 1 T) was applied for 3, 6 and 12 min. The highest germination ability of carrot seedlings was observed for 20 and 80 % algal extract. The weakest germination was observed for the highest concentration of algal extract causing the highest amount of abnormal and dead seedlings. Parallel use of seeds stimulated with magnetic field and algal extract did not increase the number of germinated seeds significantly. Carrot’s seeds treated with algal extract showed increased content of elements - macro- Ca, K, Mg, S and microelements Cu, Fe, Mn and Zn. Future experiments are required to confirm the stimulation effect of algal extract (optimal concentration) and magnetic field (various induction values) on seeds germination.

Abstract

The aim of the study was to determine the effect of Aloe vera (L.) Burm.f. (Aloe) and Morinda citrifolia L. (Indian mulberry) plant extracts and disinfectant Huva-San TR 50 (hydrogen peroxide stabilized with silver ions) on carrot seed quality. The seeds of two carrot cultivars Amsterdam (sample I) and Berlikumer 2 (sample II), were soaked in solutions of Aloe and Indian mulberry extracts and Huva-San TR 50 at concentrations of 0.025 %, 0.05 % and 0.1 % for 30 min. Untreated seeds and seeds soaked in distilled water for 30 min were used as controls. Seed germination was assessed after 7 and 14 days of incubation. The speed and uniformity of seed germination (vigour) were evaluated. Mycological analysis was performed using a deep-freeze blotter test. Sample I was characterized by lower germination at the first and the final counts than sample II and higher seed infestation with Alternaria radicina. Treating seeds of sample I with Morinda citrifolia plant extract at concentrations of 0.025 and 0.05 % reduced their infestation with Alternaria alternata and A. radicina, increased germination at the first and the final counts, and did not affect seed vigour. The effects of Aloe extract and disinfectant Huva-San TR 50 on seed quality parameters varied depending on their concentration. Hence, further studies are necessary to establish the optimal conditions for carrot seed treatment.

Abstract

Airlines are an important part of the comprehensive transportation system. Therefore, it is of great practical significance to empirically analyse the measurement of airlines’ environmental efficiency and influencing factors. Adopting the SBM-DEA model, this study measured the environmental efficiency of 20 Chinese airlines between 2010 and 2017 and empirically analysed the factors influencing their environmental efficiency using a Tobit regression model. Spring Airlines, China Southern Airlines, and Hainan Airlines were found to have the highest environmental efficiency. Tianjin Airlines, Hebei Airlines, and China Express Airlines had the lowest environmental efficiency. The Tobit regression results showed that average flight distance, load factor, market share, and proportion of cargo and mail turnover had a significant positive effect on airline environmental efficiency. Fuel consumption per ton-km had a significant negative effect on airline environmental efficiency.

Abstract

Driven by the current development of quantitative structure-properties relationship (QSPR) methods in the environmental science, we proposed an approach based on chemometric tools for selection of appropriate physicochemical parameters of radiopharmaceuticals residuals for predicting of partitioning, hazards and biodegradation of such compounds into the environment or into wastewater treatment plant. The present scheme was successfully applied for prediction of missing values for 24 different physicochemical and assessment response of the environmental fate descriptors for 11 tetrazine derivatives and 12 cyclooctene derivatives. The multivariate statistics was also proved to be useful in the evaluation of the obtained modelling results for identification of the ecological effect of radiopharmaceuticals residuals. The presented approach can be one of the first steps and support tools in the assessment of chemicals in terms of their environmental impact. The problem studies are significant since it allows a special point of view to the underestimated radiopharmaceutical pollutants.

Abstract

The aim of biomonitoring is assessment of environment condition. Biomonitoring studies with the use of mosses focus mainly on analytes accumulation and determining elements’ concentrations in the study area. It is often forgotten that a bioindicator should be alive during biomonitoring studies (which can be determined by, e.g., analysis of chlorophyll content). The objective of the carried out research was an assessment of the influence of selected heavy metals concentration: Ni, Cu, Zn, Cd and Pb accumulated by Pleurozium schreberi mosses during 3-month exposition within active biomonitoring, on their vitality, assessed by an analysis of a and b chlorophyll concentrations. The studies were also carried out in laboratory conditions, where the content of the dyes was determined with the aid of a UV-Vis spectrophotometer, in mosses reacting with solutions of various concentrations of the analysed metals. The content of elements in mosses after exposition and in solutions prior and after sorption were determined with the use of atomic absorption spectrometry (AAS) in a flame atomiser. After the carried out studies it was determined that mosses, during 12-week long exposition, accumulated heavy metals, which did not clearly influence the changes in chlorophyll content. The carried out studies prove that heavy metals are not the only and determining factor, which influences chlorophyll content in mosses as well as the bioindicator’s vitality in the conditions of environmental stress.