Unexpected toxicity decrease during photoelectrochemical degradation of atrazine with NaCl

This report shows an unexpected toxicity decrease during atrazine photoelectrodegradation in the presence of NaCl. Atrazine is a pesticide classified as endocrine disruptor occurring in industrial effluents and agricultural wastewaters. We therefore studied the effects of the degradation method, electrochemical and electrochemical photo-assisted, and of the supporting electrolyte, NaCl and Na₂SO₄, on the residual toxicity of treated atrazine solutions. We also studied the toxicity of treated atrazine solutions using Artemia nauplii. Results show that at initial concentration of 20 mg L⁻¹, atrazine was completely removed in up to 30 min using 10 mA cm⁻² electrolysis in NaCl medium, regardless of the electrochemical method used. The total organic carbon removal by the photo-assisted method was 82% with NaCl and 95% with Na₂SO₄. The solution toxicity increased during sole electrochemical treatment in NaCl, as expected. However, the toxicity unexpectedly decreased using the photo-assisted method. This finding is a major discovery because electrochemical treatment with NaCl usually leads to the formation of toxic chlorine-containing organic degradation by-products.     

Molecular population genetics of male and female mitochondrial genomes in European mussels <Emphasis Type="Italic">Mytilus</Emphasis>

The doubly uniparental system of mitochondrial inheritance (DUI) is best known in marine mussels Mytilus. Under DUI there are two types of mitochondrial DNA (mtDNA). The female type (F) is transmitted to offspring of both genders and the male type (M) exclusively to sons; consequently two distinct mtDNA lineages exist. The M lineage evolves under more relaxed selection than the F lineage resulting in higher polymorphism within the M lineage. Though this polymorphism is expected to make inferences on fine population structure easier using M instead of F data, no comprehensive comparative data exist to support this claim. We sequenced a 1,205 bp fragment of M and F mtDNA comprising parts of the COIII and ND2 genes, and analysed 204 individuals representing three Mytilus species: M. edulis, M. galloprovincialis and M. trossulus from 13 European sampling sites. A clear distinction between Mediterranean and Atlantic populations was found with both M and F data, but much better geographic differentiation was found within the Atlantic using F rather than M data. In particular, Atlantic M. galloprovincialis can be differentiated from Atlantic M. edulis, and further subdivision of Atlantic M. edulis is possible using the F data but not the M data. Multiple tests of selection were carried out to attempt to explain this paradox. We concluded that the overall pattern of polymorphism is consistent with strong purifying selection; not only is this selection relaxed in the M lineage in comparison with the F lineage, but it is also more frequently interrupted by periodic selective sweeps within the M lineage.     

Water extractable organic carbon in untreated and chemical treated biochars

Biochar, as a soil amendment, can increase concentrations of soil organic matter, especially water-extractable organic carbon (WEOC). This can affect the adsorption-desorption equilibrium between the dissolved solid phases in soil organic matter. Dissolved organic carbon (DOC) represents a small proportion of soil organic matter, but is of significant importance in the soil ecosystem due to its mobility and reactivity. Here, water extracts obtained from twelve non-herbaceous biochars (before, and after, chemical treatment with either H(3)PO(4) or KOH), were tested by Liquid Chromatography - Organic Carbon Detection (LC-OCD) to identify the effects of both pyrolysis conditions and chemical treatments on WEOC content. LC-OCD has the capacity to provide a fingerprint of WEOC, which allows analysis of the various fractions present. WEOC content was affected by both the pyrolysis temperature and the feedstock used. High mineral ash contents deriving from the feedstock can prompt thermochemical reactions of lignocelluloses to produce a relatively high WEOC content, which includes low molecular weight neutrals and humic acids as dominant components. A significant change in WEOC occurred during pyrolysis due to secondary reactions which resulted in a much lower WEOC in the high temperature biochars where fractions of low molecular weight acids and neutrals are dominant. Chemical treatments with H(3)PO(4) or KOH increased WEOC concentration, possibly by promoting hydrolysis reactions on biochar surfaces. These observations assist in assessing the contribution of biochar additions to the soil ecosystem and demonstrate the utility of LC-OCD in providing an understanding of how biochar additions to soil can alter DOC.     

Cultivable microbiome and its resistance to antimicrobials isolated from <Emphasis Type="Italic">Zaprionus indianus</Emphasis>

The objective of this study was to identify Z. indianus in PEJC and PESCAN. Listed are the following methods: to isolate bacteria from the integument of the Z. indianus species collected and to check the resistance of microorganisms to antibiotics. Collections of Z. indianus were performed in four seasons of the two parks. The results obtained suggest that the low amount of Z. indianus collected can be justified by environmental factors such as high average temperature and low average humidity. It is noted that there is a predominance of bacteria of the Enterobacteriaceae family found in both the PEJC and the PESCAN. The antibiogram performed for the isolated PEJC bacteria shows statistical significance when comparing the edge and inside values of the park. Studies with fungi were also carried out, and it was evidenced that Trichophyton spp. was the genus that most inhabited the two environments studied. The ability of fluconazole and ketoconazole to inhibit fungal growth was also investigated, and considering the concentration tested may suggest that they have good action spectra. Plasmid profile data show that 60% of antibiotic-resistant bacteria have plasmids. The values found show that Z. indianus can act as vectors of microorganisms that affect the healthy animals and humans and that these organisms may be influenced by seasons.     

Geographical location and key sensitivity issues of post-industrial regions in Europe

Primary objectives of our work were to spatially delineate post industrial areas of the EU-27 and indicate key environmental, social and economic sensitivity issues for these regions. The density of industrial sites within NUTS-x regions for EU-27 countries was assessed by using CORINE 2000 land cover layer. A development of postindustrial society in Europe represents a strong geographic diversity. There are distinct historical and current differences between regions which form major groups, comprising similar internal characteristics and definable trends in environmental and socioeconomic sense. Regions grouped into postindustrial clusters are fundamentally different from the European average, and are facing specific problems related to global market and political changes. Eastern postindustrial regions can be characterized as socially and economically weak, exhibiting high unemployment rate, low GDP, negative population growth and a strong environmental pressure, represented by a high density of dump sites. Most of the western EU postindustrial areas have been successfully recovered and moved into new economy as shown by most of the indicators. In urban postindustrial zones, however, emission sources of pollutants seem to continually be a major problem--not necessarily in terms of exceeding thresholds, but through a remarkable difference in the amount of pollutants produced relative to other regions.     

Impact of agriculture and land use on nitrate contamination in groundwater and running waters in central-west Poland

Protected areas due to their long-term protection are expected to be characterized by good water quality. However, in catchments where arable fields dominate, the impact of agriculture on water pollution is still problematic. In Poland, recently, the fertilization level has decreased, mostly for economic reasons. However, this applies primarily to phosphorus and potassium. In order to evaluate the impact of agriculture on water quality in a protected area with a high proportion of arable fields in the aspect of level and type of fertilization, complex monitoring has been applied. The present study was carried out in Wielkopolska National Park and its buffer zone, which are protected under Natura 2000 as Special Areas of Conservation and Special Protection Areas. The aim of the study were (1) to assess the impact of agriculture, with special attention on fertilization, on groundwater, and running water quality and (2) to designate priority areas for implementing nitrogen reduction measures in special attention on protected areas. In our study, high nitrogen concentrations in groundwater and surface waters were detected in the agricultural catchments. The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed. The highest nitrogen concentrations were noted in spring after winter freezing, with a small cover of vegetation, and in the areas with a high level of nitrogen application. In the studied areas, both in the park and its buffer zone, unfavorable N:P and N:K ratios in supplied nutrients were detected. Severe shortage of phosphorus and potassium in applied fertilizers is one of the major factors causing leaching of nitrogen due to limited possibilities of its consumption by plants.     

Creating an emission model based on portable emission measurement system for the purpose of a roundabout

Environmental Science and Pollution Research - Road transport is the main source of pollution to the environment in urban areas; therefore, there is a need to accurately estimate the amount of...     

Influence of physical factors on polycyclic aromatic hydrocarbons (PAHs) content in vegetable oils

The aim of this study was to test the hypothesis about physical factors causing a significant decrease of polycyclic aromatic hydrocarbon (PAH) compounds in foodstuffs. For this purpose, extraction of 16 PAHs (prioritised by EPA) from selected foodstuffs (rapeseed oil and sunflower oil) was carried out. The changes in PAH content in oils exposed to selected physical factors (UV radiation, temperature and time) were observed. Oils under study were exposed to two types of UV radiation: direct and indirect (through a glass plate). In both experiments, a reduction of 16 PAHs in oils was recorded but in the latter a PAH reduction was not as high. In another experiment, the temperature of oils was raised to 40, 100 and 200°C. As a result, the content of PAHs has decreased significantly. In both cases, exposure to UV radiation and high temperature resulted in the reduction of PAHs, it was strongly correlated with the duration of experiments. The results showed relatively low contamination of oil with PAHs. Only for rapeseed oil, the level of said contamination was substantially higher than laid down limits.     

Biodegradation of Thermoplastic Polyurethanes from Vegetable Oils

Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration were prepared. Soft segment concentration was varied from, 40 to 70 wt%. Biodegradation was studied by respirometry. Segmented polyurethanes with soft segments based on polyricinoleic acid degrade relatively slow losing about 11% carbon after 30 days, but faster than corresponding petrochemical polyesterurethanes. Since biodegradation proceeds mainly through the soft segments, higher soft segment content polymers displayed slightly higher biodegradation. Polyurethanes with dispersed hard domains in the soft phase displayed slightly faster biodegradation than those with co-continuous morphology. Polyester diol degrades slower than castor oil but significantly faster than the polyurethanes with built in soft segments from the same diol. Castor oil biodegrades slower than soybean oil.