The seasonal workers’ wellbeing in Greek islands hospitality industry

https://www.ester.ee/record=b5377459*es

Nanocrystalline TiO2 and halloysite clay mineral composite films prepared by sol-gel method:Synergistic effect and the case of silver modification to the photocatalytic degradation of basic blue- 41 azo dye in water

Tubular halloysite clay mineral and nanocrystalline TiO2 were incorporated in the preparation of nanocomposite films on glass substrates via sol-gel method at 450 °C. The synthesis involves a simple chemical method employing nonionic surfactant molecule as pore directing agent along with the acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material and lead to the formation of TiO2 nanoparticles homogeneously distributed on the surface of the halloysite. Nanocomposite films without cracks of active anatase crystal phase and small crystallite size on halloysite nanotubes are characterized by microscopy techniques and porosimetry methods in order to examine their structural properties. The composite halloysite-TiO2 films with variable quantities of halloysite were examined as photocatalysts to the discoloration of Basic Blue 41 azo dye in water. These nanocomposite films proved to be very promising photocatalysts and highly effective to dye's discoloration in spite of small amount of halloysite/TiO2 catalyst immobilized onto glass substrates. It also has been shown that the efficiency of the halloysite/TiO2 films could be further improved when silver particles were deposited on their surface after successful adsorption from an aqueous solution of a silver salt and UV reduction of the adsorbed ions

Self-cleaning properties of TiO2/palygorskite and TiO2/halloysite nanocomposite coatings

Tubular halloysite and microfibrous palygorskite clay mineral combined with nanocrystalline TiO 2 are involved in the preparation of nanocomposite films on glass substrates via sol-gel route at 450°C. The synthesis employing nonionic surfactant molecule as pore directing agent along with the acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material lead to the formation of TiO 2 nanoparticles homogeneously distributed on the palygorskite and halloysite surfaces. Nanocomposite films without cracks of active anatase crystal phase on palygorskite and halloysite surfaces are characterized by microscopy techniques, UV-Vis spectroscopy, and porosimetry methods in order to examine their structural properties. The composite palygorskite- TiO 2 and halloysite/ TiO 2 films with variable quantities of palygorskite and halloysite were tested as photocatalysts in the photo-oxidation of Basic Blue 41 azo dye in water. These nanocomposite films proved to be most promising photocatalysts and highly effective to dye’s decoloration in spite of small amount of palygorskite/ TiO 2 or halloysite/ TiO 2 catalyst immobilized onto glass substrates

The Influence of Olive Orchards Copper-Based Fungicide Use, in Soils and Sediments—The Case of Aetoliko (Etoliko) Lagoon Western Greece

In this study, soil and aquatic sediments were sampled in the Aetoliko Lagoon and its catchment area, which is exclusively dominated by olive orchards. For the first time in Greece, soil as well as sediments samples of one coherent protected aquatic ecosystem were directly compared. In order to determine the influence that the usage of copper-based fungicides have on the lagoon sediments and on the soils of the surrounding area, twenty five (25) soil samples from different olive orchards that are bordering the water body and ten (10) sediment samples from the bottom of the lagoon were taken. The samples were analyzed for total copper content (total digestion) and extractable copper (diethylenetriaminepenta acetic acid, DTPA, extraction method). Furthermore, soil/sedimentological and geochemical analyses such as pH, grain size, total organic carbon, total sulfur, total nitrogen, and calcium carbonate content were carried out. The results show that the total copper in soils ranges from 58.37 to 671.33 mg kg −1 . In addition the DTPA-extractable copper in soils has an average value of 45.00 mg kg −1 . The average value of total copper in soils (286.24 mg kg −1 ) is higher than the threshold value for the Cu concentration (100 mg kg −1 ) set by the EU countries. Total copper content in the lagoon sediments is lower than in soils and varies between 43.85 mg kg −1 and 71.87 mg kg −1 . The DTPA-extractable copper in sediments is in low ranges from 0.14 to 0.60 mg kg −1 . On average, the total copper value for the lagoon sediments (55.93 mg kg −1 ) exceeds the Toxicity Screening Value (25.20 mg kg −1 ) for Cu in freshwater sediments. From the present study, it is clear that, although the copper in soils of the surrounding lagoon area exceeds the threshold limit for ecological risk, the lagoon sediments are influenced in a smaller degree. Our study can be used as a valuable reference and baseline for future studies on the environmental monitoring of the Aetoliko lagoon, as well as for studies in similar ecosystems

Biogeochemical processes at the sediment-water interface in a Northeastern Atlantic abyssal locality (Porcupine Abyssal Plain)

Abstract Temporal and spatial variability in the composition of suspended particulate material (SPM) was found at a Northeastern Atlantic abyssal locality on the Porcupine Abyssal Plain at a depth of 4850 m. Total SPM was distinctly higher in July 1997 than in March-April 1997 and October 1996. The 20 m of water immediately overlying the seabed was strongly influenced by resuspension and the suspended particulate matter was enriched with iron and manganese. Two water distinct layers, which were characterized by being enriched with SPM, Fe p , Mn p and Al p , were encountered during all sampling periods at depths of 4000 m and 4800 m. The enrichment of SPM with biogenic elements such as Ba, Ca and Sr implies it has a high biogenic content. Increases were observed in the concentrations of these biogenic elements throughout the sampling period, which indicates that the biogenic content of the SPM was steadily increased. SPM content and element/aluminum ratios increased in the spring and summer of 1997 compared to autumn 1996, probably as a result of increases in primary productivity, coincidental increases in near-bottom current velocities and possibly other processes such as increases in bacterial activity and bioturbation. Authigenic formation of solid phases of Fe and Mn were also influencing the spatial variability. Chemical reactions involving organic carbon and oxygen, which lead to the incorporation of iron and manganese in various forms into sediments were deduced. It is proposed that there was formation of lepidocrocite (γ-FeOOH) in the presence of organic carbon and oxygen, and also that iron may also have been transformed into Fe 2 O 3 . Re-precipitation of Fe and Mn is strongly enhanced by their enrichment in the SPM in the bottom waters. The sediments predominantly consist of biogenic carbonates and can be characterized as foraminiferal ooze. The proportion of these biogenic carbonates proved to be higher in the more recent sediments, either as result of recent increases in total primary productivity or because of carbonate dissolution within the subsurface sediments. Parallel increases of Mn, Fe and carbonates in the sediment layers supports the idea that the metallic ions are being adsorbed on to calcite surfaces, rather than being co-precipitated in the carbonate phases. Reprecipitation of iron and manganese in other solid phases with the involvement of organic carbon (C org ) in the oxygen penetration zone is suggested

A review of lanthanum nanoparticles impregnated compound arsenic fixation behaviour in copper aqueous solution

Abstract: Mining is a strategic sector of the global economy. However, the effects of mining and mineral processing activities on human health and environment cannot be overemphasized. The prevailing areas of concern include: air quality, water quality, water quantity and the ecological impacts of these activities. Mines activities bring about the release of used water into the environment, nearby rivers or into the ground. Streams, wells and lakes surrounding the mines and the underground water are affected by these mining and mineral processing activities. Arsenic is a major trace impurity that contaminates the air and water surrounding copper mines as a result of the various activities of mining and mineral processing. It therefore poses a worrisome threat to human health and sustainability of the environment. The use of lanthanum nanoparticles impregnated compound has been identified as an effective adsorption technique for the immobilization of arsenic from numerous aqueous solutions. The leaching behaviour of copper and arsenic were analyzed in this review to provide a knowledge on the behaviour of different adsorbents such as lanthanum nanoparticles impregnated compounds during the adsorption reactions..

European policies and legislation targeting ocean acidification in european waters - Current state

Ocean acidification (OA) is a global problem with profoundly negative environmental, social and economic consequences. From a governance perspective, there is a need to ensure a coordinated effort to directly address it. This study reviews 90 legislative documents from 17 countries from the European Economic Area (EEA) and the UK that primarily border the sea. The primary finding from this study is that the European national policies and legislation addressing OA is at best uncoordinated. Although OA is acknowledged at the higher levels of governance, its status as an environmental challenge is greatly diluted at the European Union Member State level. As a notable exception within the EEA, Norway seems to have a proactive approach towards legislative frameworks and research aimed towards further understanding OA. On the other hand, there was a complete lack of, or inadequate reporting in the Marine Strategy Framework Directive by the majority of the EU Member States, with the exception of Italy and the Netherlands. We argue that the problems associated with OA and the solutions needed to address it are unique and cannot be bundled together with traditional climate change responses and measures. Therefore, European OA-related policy and legislation must reflect this and tailor their actions to mitigate OA to safeguard marine ecosystems and societies. A stronger and more coordinated approach is needed to build environmental, economic and social resilience of the observed and anticipated changes to the coastal marine systems

Effect of thermal comfort on occupant productivity in office buildings : response surface analysis

Thermal environment is one of the main factors that influence occupants' comfort and their productivity in office buildings. There is ample research that outlines this relationship between thermal comfort and occupant productivity. However, there is a lack of literature that presents mathematical relationship between them. This paper presents a research experimental study that investigates effects of indoor environmental quality factors on thermal comfort and occupant productivity. This study was conducted by collecting indoor environmental quality parameters using sensors and online survey for twelve months. Data analysis was done using Response Surface Analysis to outline any mathematical relationship between indoor environmental quality and occupant productivity. The outlined relationships confirmed dependencies of occupant thermal comfort and productivity on various indoor environmental factors. These dependencies include the effect of CO2 concentration, VOC concentration. These relationships were analysed to rank nine indoor environmental parameters as per the degree of effect on occupant thermal comfort and productivity. These findings would help design professionals to design better office design that would improve occupants’ comfort and their productivity. Study results have different implications for professionals working in design, construction and operation of office buildings. It is recommended that design guidelines for office buildings should consider occupant productivity and incorporate recommended range for indoor environmental quality parameters in respective categories and criteria