Mercury in fish tissues in the area of Malachov Hg-ore deposit (Slovakia)

Environmental Geochemistry and Health - The abandoned Malachov deposit belongs among the most important historic Hg deposits in the world. The soil, groundwater, surface water, plants, and animals...     

Aliphatic and polycyclic aromatic hydrocarbons in the bottom sediments from Klaipėda Harbour,Lithuania (Baltic Sea)

A total of 22 bottom surface sediment samples were collected from Klaip?da Harbour, Lithuania (Baltic Sea). Sediment parameters, such as grain size and concentrations of total organic carbon, aliphatic hydrocarbons (ALHs) and polycyclic aromatic hydrocarbons (PAHs), were determined. Hydrocarbon contamination levels in the sediments were estimated based on classifications provided in the literature, and potential biological effects were assessed based on the effects range low–effects range median values of the Sediment Quality Guidelines and on the total toxic benzo(a)pyrene equivalent. The results demonstrated that concentrations of PAHs and total aliphatic hydrocarbons in the sediments varied between 1.6 and 5456?ng?g^?1 d.w. and 6.9 and 727?μg?g^?1 d.w., respectively. In most cases, the concentrations of ALHs and PAHs in the sediments indicated low to moderate levels of pollution and were not observed to have any significant adverse effects on living biota. To determine possible sources of hydrocarbons, hydrocarbon compositions were analysed, and ALHs’ and PAHs’ specific diagnostic ratios were calculated. According to the results, the Klaip?da Harbour bottom sediments were dominated by PAHs of pyrogenic origin, whereas the origin of ALHs was mixed, that is, anthropogenic with a biogenic (aquatic and terrestrial) input.     

Agent-based framework for modeling and simulation of resources in self-sustainable human settlements: a case study on water management in an eco-village community in Croatia

A newly developed agent-based framework for modeling, simulation, and evaluation of resource management in self-sustainable human settlements is presented, along with the ability of the framework to prolong the self-sustainability of the observed human settlement system in the simulation environment. In this study the focus is on the analysis of a conducted water management simulation based on observations of an existing eco-village in Croatia, in the context of producing, storing, and consuming water as a resource. The conducted research shows that the developed framework was able to prolong the self-sustainability of localized water production, storage, and consumption dynamics when managing the water allocation with the use of self-sustainability mechanisms, in comparison to water management without using such mechanisms, under the same initial conditions. The work is placed within the context of sustainable development, Internet of Things, as well as Environmental Internet of Things areas of research, analyzing the ambiguous relationship between the terms ‘sustainable development’ and ‘self-sustainability’.     

Metal contamination recorded in the sediment of the semi-closed Bakar Bay (Croatia)

This study presents metal levels in the sediments of the Bakar Bay, with its main goal to evaluate recent anthropogenic influence, as well as over previous decades. Sediment profiles at 7 sampling points were taken. Chemical contents in bulk sediment were obtained using ICP, ICP-MS, and AAS methodologies, and 20 most significant elements were presented. Concentrations of selected elements were evaluated by factor statistical analyses to identify their source. Also, metal enrichment factor and geoaccumulation index were calculated, and spatial distribution maps for three sediment layers were constructed. Measured metal concentrations in sediment were compared with concentrations in other sediments from the Adriatic Sea. In addition, a set of sediment quality guidelines were also applied in order to predict the probability of adverse biological effects on the benthic community: This was found not to be very serious. Factor analysis clearly demonstrates the segregation between metals of natural origin resulted from soil and bedrock weathering (Li, Al, Cr, Sc), and with two anthropogenic sources originating from the city of Bakar and bulk cargo terminal (Hg, Pb, Zn, Ag, Sn, and Fe). Mercury (max 0.65 μg g^?1) is found to be the heaviest contaminant, followed by lead (max 71.5 μg g^?1), copper (89.3 μg g^?1), and zinc (156 μg g^?1). However, this study shows that Bakar Bay is considerably less polluted with toxic metals than it was believed.     

Efficient uranium immobilization on red clay with phosphates

Uranium is a very toxic and radioactive element. Removal of uranium from wastewaters requires remediation technologies. Actual methods are costly and ineffective when uranium concentration is very low. Little is known about the enhancement of sorption of uranyl ions by phosphate ions on aluminosilicates. Here, we studied sorption of uranyl acetate on red clay in the presence of phosphates. The concentration of U(VI) ranged 0.0001–0.001 mol/L, whereas the concentration of PO₄ ^3? was constant at 0.0001 mol/L. We designed a new method for the analysis of ternary surface complexes. We observed for the first time a remarkable improvement of U(VI) sorption on red clay under the influence of phosphates. We also found that at least two different ternary surface complexes U(VI)–phosphate–clay are formed in the sorbent phase. The complexation of UO₂ ²⁺ cations by phosphate ligands in the sorbent phase was confirmed by the X-ray photoelectron spectra of U 4f electrons.     

Utilization of Natural Oils for Decomposition of Polyurethanes

The model polyurethane foam and model compact polyurethane material were prepared and then decomposed by means of natural oils. Castor oil and fish oil based polyol were used in this study. Optimal conditions for the polyurethane decomposition were found. Temperature 250 °C was necessary for efficient polyurethane decomposition by castor oil whereas 200 °C is sufficient in the case of fish oil based polyol. Prepared products have hydroxyl number in the range of 95–168 mg KOH g⁻¹. During the polyurethane decomposition no cleavage of double bonds in the fatty acid chains of castor oil and fish oil based polyol was observed.     

Microbiological and mycotoxicological contamination in Slovenian primary grain production

This study was aimed at investigating the contamination of grains, which are grown and used for animal diets by Slovene farmers. A total of 107 samples were examined for mesofilic aerobic molds and yeasts. The leading contaminants among molds were from Fusarium spp., detected in 73 samples, mostly in maize (50). In accordance with the European Feed Microbiology Organisation criteria, 68% of all tested samples were of the quality level I, with normal microbiological flora, and 9% of samples were estimated as quality level IV and not suitable for animal feed. Using liquid and gas chromatography methods, the presence of various mycotoxins (expressed as 12% of moisture content) was found in 77% of all samples; mostly deoxynivalenol (71%) in concentration of 150–14,420 µg kg^?1, followed by zearalenone (32%, 20–640 µg kg^?1), fumonisin B1 (31%, 10–4863 µg kg^?1), fumonisin B2 (22%, 10–1629 µg kg^?1), while HT-2 and T-2 toxins were found in low concentration in two samples, and aflatoxin B1 and ochratoxin A in one sample. By statistical evaluation, significant positive correlations were noted between the presence of deoxynivalenol and zearalenone as well as between fumonisin B1 and B2.     

Environmental human silver exposure

Environmental exposure to silver (Ag) was assessed in occupationally non-exposed adult human population by analyzing Ag in the hair (H?·?Ag) and whole blood (WB?·?Ag). H?·?Ag was analyzed in 311 (123 men, M; 188 women, W); while WB?·?Ag was determined in 235 of these individuals (90 M, 145 W). Women had more H?·?Ag than men (M 0.05 vs. W 0.076), whereas WB?·?Ag concentrations in men and women were not significantly different. A natural distribution of the median derivatives was utilized to generate the dataset to fit the logistic sigmoid curve to assess the current human body burden of environmental Ag population exposure for M and W separately. The H?·?Ag (µg?g^?1) below 0.0105 for M and 0.0145 for W, reflects low level of environmental Ag exposure. The adaptive physiological saturation phase followed where H?·?Ag rose rapidly, first for M and then for W in parallel with biological assay. Both parallel saturation curves converged and plateaued at 0.215 for M and 0.965 for W (µg?g^?1). The current level of human environmental Ag exposure is low, but cases of high Ag exposure occurred sporadically. In conjunction with the medical histories overt clinical neural toxicity may be expected for H?·?Ag at 4?µg?g^?1and higher. There were no significant correlation between the H?·?Ag and WB?·?Ag.     

Treatment and skin decontamination of sarin intoxicated mice

Abstract

This study aimed at evaluating the efficacy of oral treatment and skin decontamination with the mineral cationic carrier in sarin-intoxicated mice. Mice were contaminated with increasing percutaneous sarin doses and decontaminated. Furthermore, the surviving mice were treated per os. The behavioral patterns of the surviving animals were monitored for 72?h, including the animals’ posture, desire for food and water, and approach and touch response. The results showed the mineral cationic carrier to be capable of efficiently decontaminating animals percutaneous poisoned with triple lethal dose. The comparison of behavioral pattern of control animals against those treated per os showed statistically significant differences. Oral treatment with mineral cationic carrier may be a detoxification tool against nerve agents’ poisoning, and this merits further research.     

Catalytic decomposition of hypochlorite ion in petrochemical plant waste water

During the incineration of the chlorinated hydrocarbons originating as the side products in vinyl chloride plant, hypochlorite ion appears as a pollutant in plant waste water. To remove it to the permitted level of 2 mg/l the process of the catalytic oxidation by cobalt (II, III) oxide, followed by sodium sulphite treatment has been chosen. It was shown that the above choice gives satisfactory results. The influence of some parameters such as retention time, effluent pH and temperature versus removal efficiency have been determined.