Тренинговые услуги в украинском туризме: состояние, тенденции, проблемы

Целью данной статьи является анализ места и роли тренингов в системе туризма Украины на фоне общемировых тенденций

Effects of high pressure and temperature conditions on the chemical fate of flowback water related chemicals

Environmental risk assessment is generally based on atmospheric conditions for the modelling of chemical fate after entering the environment. However, during hydraulic fracturing, chemicals may be released deep underground. This study therefore focuses on the effects of high pressure and high temperature conditions on chemicals in flowback water to determine whether current environmental fate models need to be adapted in the context of downhole activities. Crushed shale and flowback water were mixed and exposed to different temperature (25–100 °C) and pressure (1–450 bar) conditions to investigate the effects they have on chemical fate. Samples were analysed using LC-HRMS based non-target screening. The results show that both high temperature and pressure conditions can impact the chemical fate of hydraulic fracturing related chemicals by increasing or decreasing concentrations via processes of transformation, sorption, degradation and/or dissolution. Furthermore, the degree and direction of change is chemical specific. The change is lower or equal to a factor of five, but for a few individual compounds the degree of change can exceed this factor of five. This suggests that environmental fate models based on surface conditions may be used for an approximation of chemical fate under downhole conditions by applying an additional factor of five to account for these uncertainties. More accurate insight into chemical fate under downhole conditions may be gained by studying a fluid of known chemical composition and an increased variability in temperature and pressure conditions including concentration, salinity and pH as variables.</p

Natural isotopes support groundwater origin as a driver of mire type and biodiversity in Slitere National Park, Latvia

Contains fulltext : 219073.pdf (publisher's version ) (Open Access

Comparing conventional and green fracturing fluids by chemical characterisation and effect-based screening.

There is public and scientific concern about air, soil and water contamination and possible adverse environmental and human health effects as a result of hydraulic fracturing activities. The use of greener chemicals in fracturing fluid aims to mitigate these effects. This study compares fracturing fluids marketed as either ‘conventional’ or ‘green’, as assessed by their chemical composition and their toxicity in bioassays. Chemical composition was analysed via non-target screening using liquid chromatography - high resolution mass spectrometry, while toxicity was evaluated by the Ames fluctuation test to assess mutagenicity and CALUX reporter gene assays to determine specific toxicity. Overall, the results do not indicate that the ‘green’ fluids are less harmful than the ‘conventional’ ones. First, there is no clear indication that the selected green fluids contain chemicals present at lower concentrations than the selected conventional fluids. Second, the predicted environmental fate of the identified compounds does not seem to be clearly distinct between the ‘green’ and ‘conventional’ fluids, based on the available data for the top five chemicals based on signal intensity that were tentatively identified. Furthermore, Ames fluctuation test results indicate that the green fluids have a similar genotoxic potential than the conventional fluids. Results of the CALUX reporter gene assays add to the evidence that there is no clear difference between the green and conventional fluids. These results do not support the claim that currently available and tested green-labeled fracturing fluids are environmentally more friendly alternatives to conventional fracturing fluids

KKF-Model Platform Coupling : summary report KKF01b

Nederland bereidt zich voor op een sneller stijgende zeespiegel en een veranderend klimaat. Hiervoor is het Deltaprogramma gestart. Dit deltaprogramma voorziet een serie beslissingen die grote gevolgen zullen hebben voor het beheer van het water in Nederland. Om deze beslissingen zorgvuldig te nemen is informatie nodig over hoe het klimaat en de stijgende zeespiegel dit waterbeheer zullen beïnvloeden. De modellen die de gevolgen van klimaatverandering berekenen zullen daarom met dezelfde klimaat forcering en gekoppeld aan elkaar moeten worden gebruikt. In dit onderzoek is gekeken naar het linken van hydrologische en hydrodynamische modellen – en daaraan gekoppelde modellen die de ontwikkelingen in natuur en landgebruik modelleren -- die het gebied van de Alpen tot en met de Noordzee inclusief Nederland beschrijven

Solute transport by groundwater flow to wetland ecosystems : the environmental impact of human activities

This thesis deals with solute transport by groundwater flow and the way in which solute transport is affected by human activities. This in relation to wetland ecosystems. Wetlands in the eastern part of the Vecht river plain in The Netherlands are historically renown for their great variety of aquatic and fen vegetation. Over the past decades a marked deterioration of wetland vegetation has been observed. In particular species of the alliance Caricion davalianae disappeared. It is generally believed that the Caricion davalianae are dependent on rather nutrient-poor (mesotrophic) calcium-rich groundwater. In the Vecht river plain this type of water naturally originates from the adjacent sandy ice-pushed ridge 'Het Gooi'. Upward seepage of ridge water in the river plain has decreased over the past decades as an effect of increasing groundwater extraction for public water supply on the ridge. The resulting water shortages on the Vecht river plain in summer are met by import of external polluted surface water. This eutrophic water has negative effects on the mesotrophic aquatic and fen vegetation. Provincial groundwater management is therefore directed towards regeneration of upward seepage of groundwater from the ridge. At the same time groundwater pollution on the ridge has increased. In time this may affect the vegetation on the river plain through solute transport by groundwater flow. Increased upward seepage from the ridge may thus have adverse effects. Specific research questions related to the vegetation on the river plain are: - to what extent is the groundwater under the ridge polluted? - are pollutants transported towards the river plain? - are pollutants retarded or chemically altered during flow? - is regeneration of upward seepage a good restoration measure; are there alternatives