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In assessment of severe accident risk in light water reactors (LWRs), steam explosion is a nonnegligible phenomenon following a relocation of core melt (corium) into coolant, and thus various research efforts have been paid to steam explosion. There had been numerous studies showing that the occurrence of steam explosions is influenced by several factors such as melt and coolant temperatures, melt materials, non-condensable gasses, etc. However, most of the existing experiments used deionized (DI) water or tap water as coolant, with little consideration of the effect of chemicals (e.g. boric acid, sodium hydroxide, sodium phosphate) commonly applied in reactor coolant. To examine the effect of the chemical additives in coolant on steam explosion, the present study performs a series of molten Tin droplet-coolant interaction tests using DI water and different chemical solutions, including H3BO3 solutions, NaOH + H3BO3 neutral solutions, and Na3PO4 + H3BO3 neutral solutions. The experimental results show that adding NaOH and Na3PO4 in boric acid solution significantly affects the occurrence probability of spontaneous steam explosion, because of the presence of PO43− and H+ ions. When different solutions have equivalent concentrations of H3BO3, the peak pressure values of the spontaneous steam explosion of Sn droplets are similar among various solutions. Compared with those in DI water, steam explosion in the chemical solutions occurs predominantly within a narrow range of depth from 28 mm to 40 mm and produces a much higher peak pressure. This implies that more energetic steam explosions may occur in the chemical solutions., QC 20231215

Initiated in 2018, solinst levellogger data is available until 2023. Data is collected each year and is uploaded soon after the water year is over. Some loggers were moved to different sites or had technical difficulties, therefore dates that have gaps in data represent a time period where data is not available.

The increasing demand for low carbon technology has increased the demand for some critical materials. Graphite is one of the strategic raw materials defined by the European Union as it is used in the production of for example batteries in electrical vehicles. Natural graphite is extracted through mining and the production is currently located outside the European Union. However, natural graphite deposits exist in for example Sweden. Mining activities can cause environmental issues, e.g. release of metals to the environment. By studying sediment in lakes, the historical element load can be investigated. In the Vittangi area (northern Sweden), a graphite deposit is located close to the natural lake Hosiojärvi. In the area, exploration has been conducted during the last 100 years. The latest exploration was conducted by the company Talga, who is also planning to extract the graphite. The aim of this master thesis is to determine the geochemical processes affecting the mobility of Co, Cu, Ni and Zn in Hosiojärvi, as well as their historical accumulation in the lake. Due to previous exploration in the area, the eventual impact from trace elements related to the bedrock and graphite deposit has also been studied. Based on previous elemental load to the sediment, the future impact until the mine starts have been discussed. The method used for answering the questions have been sampling of sediment, analysing metal concentrations in surface water, groundwater and sediment and dating of the sediment to determine sediment accumulation rate. The study shows that there has been an increase of Co, Ni and Zn to the lake, as the concentrations in the sediment has increased in the upper parts. By looking at those elements, the increase could be explained by the exploration during 1960 – 1970. The sediment is assumed to be in reduced conditions and the zone where redox processes can occur is assumed to be in the interface between the bottom water and the top sediment. In the sediment

Motivated by the interest in steam explosion in chemical solutions and seawater, a series of tests were carried out in the MISTEE facility at KTH to investigate steam explosion characteristics as multiple molten droplets of tin were falling through a coolant pool containing deionized water, boric acid solution, neutral solution of boric acid and sodium phosphate, and seawater, separately. The experimental results revealed distinct and complex characteristics of steam explosion of multiple droplets, which were not observed in previous single-droplet steam explosion experiments. The tin melt samples of 5 g and 20 g were employed to formulate different numbers of multiple droplets. In the test with 5 g melt, steam explosion was more energetic at a deeper explosion location − a similar trend found in the single-droplet steam explosion test with 1 g melt. However, the test of 20 g melt did not show a clear trend in a wide range of explosion depth. The peak pressure and impulse increased with increasing mass of melt sample. The steam explosion occurred more closely to the coolant pool surfaces in the seawater and chemical solutions than in deionized water. Steam explosion intensity was significantly reduced in a neutral solution containing 1.2 wt.% boric acid and sodium phosphate. The influence of the chemical solutions on steam explosion was diminishing in the tests with multiple droplets., QC 20240527

Acid sulfate soil comes with a broad spectrum of challenges affecting technical, economic and environmental perspectives. It can cause lowering of pH and leaching of metals and sulfate into nearby streams resulting in negative effects on the ecosystem. Management of these sediments during infrastructure projects are challenging, primarily due to the characteristics of the fine-grained sediments with poor carrying capacity. Large quantities are often transported to landfill, resulting in expensive costs. It is important to manage acid sulfate soils cautiously to prevent potential harm of the surrounding environment. During the construction of an interchange in Sikeå, northern Sweden, a large amount of acid sulfate soils has affected the construction work. Therefore, the aim of this study was to determine if any significant differences in water quality of two nearby streams could be found between upstream and downstream the interchange. The annual addition of acidic sulfate soil above the water table, within the catchment, due to isostatic land uplift was determined and compared to the amounts transported to landfill. No significant difference in water quality was found between upstream and downstream measuring points. There was a significant correlation between sulfate and conductivity but only a weak correlation between pH and sulfate. Key conclusions from this study includes that the construction of the interchange does not seem to have aggravated the water quality of nearby streams and the amount of sediment added annually above the water table by land uplift are more than twice as large as the amount that was transported to landfill.

Producción Científica, We present a study of salicylic acid and its hydrates, with up to four water molecules, done by employing chirped-pulse Fourier transform microwave spectroscopy. We employed the spectral data set of the parent, 13C, and 2H isotopologues to determine the molecular structure and characterize the intra- and intermolecular interactions of salicylic acid and its monohydrate. Complementary theoretical calculations were done to support the analysis of the experimental results. For the monomer, we analyzed structural properties, such as the angular-group-induced bond alternation (AGIBA) effect. In the microsolvates, we analyzed their main structural features dominated by the interaction of water with the carboxylic acid group. This work contributes to seeding information on how water molecules accumulate around this group. Moreover, we discussed the role of cooperative effects further stabilizing the observed inter- and intramolecular hydrogen bond interactions., Ministerio de Ciencia e Innovación - (Grant PID2021- 125207NB-C33), Junta de Castilla y León - (Grant INFRARED-FEDER IR2020-1-UVa02)

Acid sulfate soil comes with a broad spectrum of challenges affecting technical, economic and environmental perspectives. It can cause lowering of pH and leaching of metals and sulfate into nearby streams resulting in negative effects on the ecosystem. Management of these sediments during infrastructure projects are challenging, primarily due to the characteristics of the fine-grained sediments with poor carrying capacity. Large quantities are often transported to landfill, resulting in expensive costs. It is important to manage acid sulfate soils cautiously to prevent potential harm of the surrounding environment. During the construction of an interchange in Sikeå, northern Sweden, a large amount of acid sulfate soils has affected the construction work. Therefore, the aim of this study was to determine if any significant differences in water quality of two nearby streams could be found between upstream and downstream the interchange. The annual addition of acidic sulfate soil above the water table, within the catchment, due to isostatic land uplift was determined and compared to the amounts transported to landfill. No significant difference in water quality was found between upstream and downstream measuring points. There was a significant correlation between sulfate and conductivity but only a weak correlation between pH and sulfate. Key conclusions from this study includes that the construction of the interchange does not seem to have aggravated the water quality of nearby streams and the amount of sediment added annually above the water table by land uplift are more than twice as large as the amount that was transported to landfill.

The increasing demand for low carbon technology has increased the demand for some critical materials. Graphite is one of the strategic raw materials defined by the European Union as it is used in the production of for example batteries in electrical vehicles. Natural graphite is extracted through mining and the production is currently located outside the European Union. However, natural graphite deposits exist in for example Sweden. Mining activities can cause environmental issues, e.g. release of metals to the environment. By studying sediment in lakes, the historical element load can be investigated. In the Vittangi area (northern Sweden), a graphite deposit is located close to the natural lake Hosiojärvi. In the area, exploration has been conducted during the last 100 years. The latest exploration was conducted by the company Talga, who is also planning to extract the graphite. The aim of this master thesis is to determine the geochemical processes affecting the mobility of Co, Cu, Ni and Zn in Hosiojärvi, as well as their historical accumulation in the lake. Due to previous exploration in the area, the eventual impact from trace elements related to the bedrock and graphite deposit has also been studied. Based on previous elemental load to the sediment, the future impact until the mine starts have been discussed. The method used for answering the questions have been sampling of sediment, analysing metal concentrations in surface water, groundwater and sediment and dating of the sediment to determine sediment accumulation rate. The study shows that there has been an increase of Co, Ni and Zn to the lake, as the concentrations in the sediment has increased in the upper parts. By looking at those elements, the increase could be explained by the exploration during 1960 – 1970. The sediment is assumed to be in reduced conditions and the zone where redox processes can occur is assumed to be in the interface between the bottom water and the top sediment. In the sediment

By hosting significant amounts of extra-atmospheric dissolved gases, including geogenic CO2 and CH4, volcanic lakes provide relevant ecosystem services through the key role the aquatic microbial community in mediating freshwater carbon fluxes. In view of elucidating the mechanisms governing the microbial spatial distribution and the possible implications for ecosystem functioning, we compared the hydrogeochemical features and the microbial community structure of two adjacent stratified volcanic lakes (Lake Grande - LG and Lake Piccolo - LP). Water chemistry, gases and their isotopic composition were coupled with microbial pigment profiling, cell counting, and phylogenetic analyses. LP showed transparent waters with low concentrations of chlorophyll-a and the occurrence of phycoerytrin-rich cyanobacteria. LG was relatively more eutrophic with a higher occurrence of diatoms and phycocyanine-rich cyanobacteria. Considering the higher concentrations of CO2 and CH4 in bottom waters, the oligotrophic LP was likely a more efficient sink of geogenic CO2 in comparison to the adjacent eutrophic LG. The prokaryotic community was dominated by the mixothrophic hgcI clade (family Sporichthyaceae) in the LG surface waters, while in LP this taxon was dominant down to -15 m. Moreover, in LP, the bottom dark waters harbored a unique strictly anaerobic bacterial assemblage associated with methanogenic Archaea (i.e. Methanomicrobiales), resulting in a high biogenic methane concentration. Water layering and light penetration were confirmed as major factors affecting the microbial distribution patterns. The observed differences in the geochemical and trophic conditions reflected the structure of the aquatic microbial community, with direct consequences on the dynamics of dissolved greenhouse gases.

Goose and swan populations have increased concurrently with environmental degradation of wetlands, such as eutrophication, vegetation losses, and decrease in biodiversity. An important question is whether geese and swans contribute to such changes or if they instead benefit from them. We collected data from 37 wetlands in southern Sweden April - July 2021 to study relationships between geese, swans and other waterbird guilds, macrophytes, invertebrates, as well as physical and water chemistry variables. Neither goose nor swan abundance was negatively correlated with other trophic levels (abundance, richness, or cover). On the contrary, goose or swan abundances were positively related to abundances of surface and benthic feeding waterbirds, cover of specific macrophytes, and to invertebrate richness and abundance. Moreover, invertebrates (number of taxa or abundance) were positively associated with abundance of several waterbird guilds and total phosphorous with surface feeders, whereas water colour was positively (surface feeders) or negatively (benthic feeders) related. We conclude that waterbirds are more abundant in productive wetlands and that geese and swans do not show clear deleterious effects on other trophic levels included in this study. However, patterns may be masked at the species level, which should be addressed in further studies, complemented with experimental studies of grazing impact.

Ett problem vid byggandet av nya kärnkraftverk för elproduktion är de stora investeringskostnaderna samt den långa tiden det att få tillstånd för en reaktor och bygga den. Nyligen färdigställdes den tredje reaktorn vid Olkiluoto I Finland, den tog 18 år att färdigställa exklusive tiden att få tillstånd för reaktorn. Små modulära kärnkraftsreaktorer, SMR är mindre reaktorer med en lägre elektrisk effekt har föreslagits vara en lösning på problemet. Det behövs inte lika stora investeringar för att uppföra en reaktor och de ska också gå snabbare att bygga. Det finns flera fördelar med SMR, de kommer att tillverkas i fabriker vilket minskar konstruktionstiden. Samma reaktormodell behöver bara ett tillstånd för licensering medan stora reaktorer som byggs idag behöver ett nytt för varje reaktor. Det är dessutom billigare att serieproducera reaktorer då kostnaden går ned för varje producerad reaktor. De flesta reaktorer idag använder lättvatten som en moderator och för att kyla ned reaktorn, reaktorerna kallas för lätt vatten reaktorer, LWR. Det finns två vanliga designer, en där vatten kokas inuti reaktorn och driver sedan en turbin, reaktorn kallas för kokvattenreaktor, BWR. Den andra vanliga reaktordesignen är tryckvattenreaktorn, PWR där det är ett högre tryck som gör att vattnet inte kokar i reaktorn, i stället kokar det varma vattnet från reaktorn vatten i en sekundär vattenloop i en ånggenerator. Det är ångan i sekundär loopen som sedan driver turbinen. Det finns även flera reaktorkoncept som inte använder lättvatten. De SMR koncept som är närmast att påbörja konstruktion är alla LWR eftersom det är där den största erfarenheten från tidigare reaktordesigner finns. Genom att undersöka sju SMR koncept, sex PWR och en BWR är bilden att många är väldigt lika reaktorerna som finns idag, däremot så har många tagit bort komplicerade system och infört passiva säkerhetssystem som bland annat naturlig cirkulation för att få en passiv kylning. Materialen som används är också m, One problem with building new nuclear reactors for electricity production is the large investment costs and the long time needed for permissions and construction. Most recently is the Olkiluoto nuclear power plant in Finland where a third reactor was built, it took 18 years to finalize the reactor, and this is not including the time of handling the licencing application. Small modular nuclear reactors, SMR which is a smaller reactor with a reduced effect has been proposed to reduce the cost of investment and the time it takes from license application to finalized reactor. The SMR reactors have many advantages. It will be fabricated in factories reducing the time of construction, since reactor units are the same, the same reactor design only needs one licencing for all reactors. Compared to large reactors built today, where every single reactor needs a new licencing. Smaller reactors lead to shorter construction times and lower investment. It is also less expensive to produce reactors in series where the cost per unit decreases for every unit produced. Most reactors in operation today use light water as a moderator and coolant and are called light water reactors, LWR. Two designs are common, one where the water is boiled in the reactor and goes directly to the turbine, this reactor is called a boiling water reactor, BWR. The other common reactor is a pressurized water reactor, PWR where a higher pressure does not allow the water to boil. Instead, it is heated and boils water in a steam generator that then turns the turbine blades. There are other reactor concepts which do not use light water as a moderator and coolant, The SMR concepts that are the closest to construction are all LWR because it is where most experience from previous reactor designs is. By investigating seven SMR reactor concepts, six PWR and one BWR, it was concluded that they are similar to reactors operating today, but with some simplification and passive safety systems like natural circulation for

The employment of granular ferric iron-(oxy)hydroxides, a well-known economic and effective method, lowers arsenic concentrations in different water types. However, for direct application in polluted groundwaters, there is a need to develop new injectable adsorbents for aquifers that could also neutralize acidic media. In this context, a granular ferric hydroxide-calcite (GFH-C) adsorbent was size-reduced to 0.4–50 µm by sonication with the aim of improving (i) the adsorption of As(III) and As(V) at different pHs and (ii) the pH control through the dissolution of calcite. Batch experiments were conducted to determine As(III) and As(V) adsorption isotherms and kinetics, as well as calcite dissolution kinetics, using GFH-C of two sizes (granular and sonicated). Results showed that the arsenic binding capacity of sonicated adsorbents did not improve significantly. On the contrary, the As(III) and As(V) adsorption kinetics improved with the sonication, as in the case of calcite dissolution kinetics. The dissolution of calcite from the adsorbent made the water pH increase to around 9.2–9.4. The sonicated adsorbent offers an advantage in depolluting As-containing groundwater due to its smaller size, which is linked with faster arsenic adsorption and effective acidic water neutralization., Peer Reviewed, Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejament, Postprint (published version)

Los acuíferos costeros se distinguen por su singular interacción tierra-mar y la principal dificultad para estudiar estos sistemas es la complejidad de sus ciclos biogeoquímicos. Los procesos importantes en la "zona de mezcla" de los acuíferos costeros controlan el suministro y el intercambio de compuestos químicos a las aguas subterráneas y, por lo tanto, son clave para comprender los flujos de solutos suministrados por las aguas subterráneas al mar y sus impactos en los ecosistemas costeros. Este cuerpo costero conocido como “estuario subterráneo” (STE), se caracteriza por su conexión hidráulica con el mar, creando una interfaz entre el agua dulce y el agua de mar. La distribución y composición de las sustancias que fluyen de la tierra al mar cambia porque las transformaciones que se producen en el acuífero están muy influenciadas por las descargas submarinas de aguas subterráneas y por el agua salada que ha invadido el acuífero a través de la conexión con el mar. Para estudiar estos procesos, se construyó un sitio de investigación en un área de 100m de largo tierra adentro desde la línea de costa y 30m de ancho, en el acuífero aluvial de Argentona, Mataró, al noreste de Barcelona, Cataluña (España). Este sitio experimental se estableció en 2014 y ha sido equipado para el monitoreo intensivo de procesos de acuíferos costeros como la intrusión marina (SWI) y las descargas submarinas de aguas subterráneas (SGD). Actualmente se monitorea con 25 piezómetros (2 metros apantallados) distribuidos en 5 nidos de 4 piezómetros cada uno (a intervalos de 10m, 20m, 15m y 25m) y 4 piezómetros individuales. En este sistema descrito como “sistema multiacuífero y reactivo”, se caracterizaron las condiciones fisicoquímicas, microbiológicas e hidrogeoquímicas asociadas a procesos biogeoquímicos a diferentes profundidades. Para este enfoque se presentarán los nuevos resultados relacionados con una campaña de monitoreo en diciembre de 2021 que caracterizan el estuario subterráneo., Coastal aquifers are distinguished by their unique land-sea interaction and the main difficulty in studying these systems is the complexity of their biogeochemical cycles. Important processes in the “mixing zone” of coastal aquifers control the supply and exchange of chemical compounds to groundwaters, and thus are key to understand the fluxes of solutes supplied by groundwater to the coastal sea and their impacts for coastal ecosystems. This coastal body known as a “subterranean estuary” (STE), is characterized by its hydraulic connection to the sea, creating an interface between freshwater and seawater. The distribution and composition of substances flowing from land to sea change because transformations that take place in the aquifer are highly influenced by the submarine groundwater discharges and the seawater that has invaded the aquifer through the connection to the sea. In order to study these processes, a research site was constructed in an area 100 m long inland from the coastline and 30 m wide, in the alluvial aquifer of Argentona, Mataró, northeast of Barcelona, Catalonia (Spain). This experimental site was established in 2014 and has been equipped for intensive monitoring of coastal aquifer processes such as Seawater Intrusion (SWI) and Submarine Groundwater Discharge (SGD). Currently, it is monitored with 25 piezometers (2 meters screened) distributed in 5 nests with 4 piezometers each (at 10m, 20m, 15m, and 25m intervals) and 4 individual piezometers. In this system described as a "multi-aquifer and reactive system", the physicochemical, microbiological and hydrogeochemical conditions associated with biogeochemical processes at different depths were characterized. For this approach, the new results related with a monitoring campaign in December 2021 that characterize the subterranean estuary will be presented.

Dams play an important role in our society, but their negative impacts on aquatic ecosystems have led to a need for conservation efforts to mitigate the negative effects. In some instances, dam removal has been suggested to be the most economically and ecologically beneficial restoration method to improve longitudinal connectivity. This, however, has increased the need of more research about the effects dam removal have on aquatic ecosystems, since the outcomes of this restoration method can be unpredictable. In this study, I investigated ecological impacts of dam removals in Swedish inland waters. I collected field data from five different lakes in Värmland and Dalarna, two lakes with dam removal in 2017/2018 and three without. I studied how dam removal affected different trophic levels of the aquatic ecosystem, where I predicted that a top-down effect would increase abundances of piscivorous European perch (Perca fluviatilis) and zooplankton, but decrease phytoplankton, whereas a bottom-up effect would lead to increases in biomass at all trophic levels (with most pronounced effects on nutrient concentration). If both top-down and bottom-up effects would operate in parallel, all the above mentioned effects could occur. I also predicted that if dam removal affected the fish community, there would be a change in species diversity and fish biomass. Moreover, if perch demography was affected, there would be a change in perch length and abundance of different age classes. To investigate this, I collected data on fish, plankton, nutrients (P, N), DOC, pH and conductivity in the five lakes and compared this with already existing historical data using a BACI design. Two-way ANOVAs were used to study the effects of dam removals on these variables. There were not enough historical data on P concentration or zoo-and phytoplankton to be analyzed statistically. I did, however, conduct correlation analyses with zoo- and phytoplankton. Contradictory to my prediction, the results, Dammar spelar en viktig roll i vårt samhälle, men deras negativa påverkan på akvatiska ekosystem har ökat behovet av bevarandeinsatser för att minska de negativa effekterna. I somliga fall har dammutrivning föreslagits vara den mest ekonomiskt och ekologiskt gynnsamma bevarandemetoden för att förbättra longitudinell konnektivitet. Detta har dock ökat behovet av mer forskning gällande dammutrivningars effekter på akvatiska ekosystem, eftersom utfallen av denna bevarandemetod kan vara oförutsägbara. I denna studie undersökte jag dammutrivningars ekologiska effekter i svenska inlandsvatten. Jag samlade data i fält från fem olika sjöar i Värmland och Dalarna, två sjöar med dammutrivningar under 2017/2018 och tre utan. Jag undersökte hur dammutrivning påverkade olika trofiska nivåer i det akvatiska ekosystemet, med förväntningarna att en top-down-effekt skulle öka abundansen av fiskätande abborre (Perca fluviatilis) samt djurplankton, men minska växtplankton, medan en bottom-up-effekt skulle leda till ökad biomassa inom samtliga trofiska nivåer (men med mest effekter på näringskoncentration). Om både top-down- och bottom-up-effekter skulle verka parallellt kunde samtliga ovanstående nämnda effekter förekomma. Jag förväntade även att om dammutrivning påverkade fisksamhället skulle det ske en förändring i artdiversitet och fiskbiomassa. Därtill bör en effekt på demografi hos abborre leda till förändringar i abborrlängd- och abundans i olika åldersklasser. För att undersöka detta samlade jag in data över fisk, plankton, näringsämnen (P, N), DOC, pH och konduktivitet i de fem sjöarna och jämförde detta med redan existerande historiska data med en BACI design. Tvåvägs-ANOVAs användes för att studera effekterna av dammutrivningar på dessa variabler. Det fanns inte tillräckligt med historiska data över P-koncentration eller djur- och växtplankton för att analyseras statistiskt. Jag utförde dock korrelationsanalyser med djur- och växtplankton. I kontrast till min förväntan visad

Study region Our study region extends over 450 stream km of the German part of the Elbe River, an ecologically and economically important first order river, between Schöna and Wittenberge. Study focus Diffuse groundwater born nutrients are major contributors to increased algae growth in rivers, leading to eutrophication with serious consequences for water quality and ecosystem health. Therefore, knowledge of the spatial and temporal dynamics of diffuse groundwater discharge are required since groundwater often remains as a ‘black box’ for the identification of nutrient sources by managers. The multi-method approach, based on the inverse geochemical and tritium modelling, a flux balance, a darcy approach and hydraulic gradients, showed complex spatiotemporal dynamics along the studied reach of the Elbe River. Groundwater inflow was variable but occurred along the entire river. Areas of high groundwater fluxes were located in the upstream mountainous catchment areas and decreasing downstream. New hydrological insights for the region The multi-method approach provides a blueprint for the assessment of other large river systems. No single method was able to create conclusive results and most other approaches are only applicable in smaller stream systems. First time an estimation of groundwater flux rates, that can be used to quantify matter inputs, was made. In addition, we showed a way to detect and assess the impact of drainage channels in a heterogenous river system.

Ett problem vid byggandet av nya kärnkraftverk för elproduktion är de stora investeringskostnaderna samt den långa tiden det att få tillstånd för en reaktor och bygga den. Nyligen färdigställdes den tredje reaktorn vid Olkiluoto I Finland, den tog 18 år att färdigställa exklusive tiden att få tillstånd för reaktorn. Små modulära kärnkraftsreaktorer, SMR är mindre reaktorer med en lägre elektrisk effekt har föreslagits vara en lösning på problemet. Det behövs inte lika stora investeringar för att uppföra en reaktor och de ska också gå snabbare att bygga. Det finns flera fördelar med SMR, de kommer att tillverkas i fabriker vilket minskar konstruktionstiden. Samma reaktormodell behöver bara ett tillstånd för licensering medan stora reaktorer som byggs idag behöver ett nytt för varje reaktor. Det är dessutom billigare att serieproducera reaktorer då kostnaden går ned för varje producerad reaktor. De flesta reaktorer idag använder lättvatten som en moderator och för att kyla ned reaktorn, reaktorerna kallas för lätt vatten reaktorer, LWR. Det finns två vanliga designer, en där vatten kokas inuti reaktorn och driver sedan en turbin, reaktorn kallas för kokvattenreaktor, BWR. Den andra vanliga reaktordesignen är tryckvattenreaktorn, PWR där det är ett högre tryck som gör att vattnet inte kokar i reaktorn, i stället kokar det varma vattnet från reaktorn vatten i en sekundär vattenloop i en ånggenerator. Det är ångan i sekundär loopen som sedan driver turbinen. Det finns även flera reaktorkoncept som inte använder lättvatten. De SMR koncept som är närmast att påbörja konstruktion är alla LWR eftersom det är där den största erfarenheten från tidigare reaktordesigner finns. Genom att undersöka sju SMR koncept, sex PWR och en BWR är bilden att många är väldigt lika reaktorerna som finns idag, däremot så har många tagit bort komplicerade system och infört passiva säkerhetssystem som bland annat naturlig cirkulation för att få en passiv kylning. Materialen som används är också m, One problem with building new nuclear reactors for electricity production is the large investment costs and the long time needed for permissions and construction. Most recently is the Olkiluoto nuclear power plant in Finland where a third reactor was built, it took 18 years to finalize the reactor, and this is not including the time of handling the licencing application. Small modular nuclear reactors, SMR which is a smaller reactor with a reduced effect has been proposed to reduce the cost of investment and the time it takes from license application to finalized reactor. The SMR reactors have many advantages. It will be fabricated in factories reducing the time of construction, since reactor units are the same, the same reactor design only needs one licencing for all reactors. Compared to large reactors built today, where every single reactor needs a new licencing. Smaller reactors lead to shorter construction times and lower investment. It is also less expensive to produce reactors in series where the cost per unit decreases for every unit produced. Most reactors in operation today use light water as a moderator and coolant and are called light water reactors, LWR. Two designs are common, one where the water is boiled in the reactor and goes directly to the turbine, this reactor is called a boiling water reactor, BWR. The other common reactor is a pressurized water reactor, PWR where a higher pressure does not allow the water to boil. Instead, it is heated and boils water in a steam generator that then turns the turbine blades. There are other reactor concepts which do not use light water as a moderator and coolant, The SMR concepts that are the closest to construction are all LWR because it is where most experience from previous reactor designs is. By investigating seven SMR reactor concepts, six PWR and one BWR, it was concluded that they are similar to reactors operating today, but with some simplification and passive safety systems like natural circulation for

Dams play an important role in our society, but their negative impacts on aquatic ecosystems have led to a need for conservation efforts to mitigate the negative effects. In some instances, dam removal has been suggested to be the most economically and ecologically beneficial restoration method to improve longitudinal connectivity. This, however, has increased the need of more research about the effects dam removal have on aquatic ecosystems, since the outcomes of this restoration method can be unpredictable. In this study, I investigated ecological impacts of dam removals in Swedish inland waters. I collected field data from five different lakes in Värmland and Dalarna, two lakes with dam removal in 2017/2018 and three without. I studied how dam removal affected different trophic levels of the aquatic ecosystem, where I predicted that a top-down effect would increase abundances of piscivorous European perch (Perca fluviatilis) and zooplankton, but decrease phytoplankton, whereas a bottom-up effect would lead to increases in biomass at all trophic levels (with most pronounced effects on nutrient concentration). If both top-down and bottom-up effects would operate in parallel, all the above mentioned effects could occur. I also predicted that if dam removal affected the fish community, there would be a change in species diversity and fish biomass. Moreover, if perch demography was affected, there would be a change in perch length and abundance of different age classes. To investigate this, I collected data on fish, plankton, nutrients (P, N), DOC, pH and conductivity in the five lakes and compared this with already existing historical data using a BACI design. Two-way ANOVAs were used to study the effects of dam removals on these variables. There were not enough historical data on P concentration or zoo-and phytoplankton to be analyzed statistically. I did, however, conduct correlation analyses with zoo- and phytoplankton. Contradictory to my prediction, the results, Dammar spelar en viktig roll i vårt samhälle, men deras negativa påverkan på akvatiska ekosystem har ökat behovet av bevarandeinsatser för att minska de negativa effekterna. I somliga fall har dammutrivning föreslagits vara den mest ekonomiskt och ekologiskt gynnsamma bevarandemetoden för att förbättra longitudinell konnektivitet. Detta har dock ökat behovet av mer forskning gällande dammutrivningars effekter på akvatiska ekosystem, eftersom utfallen av denna bevarandemetod kan vara oförutsägbara. I denna studie undersökte jag dammutrivningars ekologiska effekter i svenska inlandsvatten. Jag samlade data i fält från fem olika sjöar i Värmland och Dalarna, två sjöar med dammutrivningar under 2017/2018 och tre utan. Jag undersökte hur dammutrivning påverkade olika trofiska nivåer i det akvatiska ekosystemet, med förväntningarna att en top-down-effekt skulle öka abundansen av fiskätande abborre (Perca fluviatilis) samt djurplankton, men minska växtplankton, medan en bottom-up-effekt skulle leda till ökad biomassa inom samtliga trofiska nivåer (men med mest effekter på näringskoncentration). Om både top-down- och bottom-up-effekter skulle verka parallellt kunde samtliga ovanstående nämnda effekter förekomma. Jag förväntade även att om dammutrivning påverkade fisksamhället skulle det ske en förändring i artdiversitet och fiskbiomassa. Därtill bör en effekt på demografi hos abborre leda till förändringar i abborrlängd- och abundans i olika åldersklasser. För att undersöka detta samlade jag in data över fisk, plankton, näringsämnen (P, N), DOC, pH och konduktivitet i de fem sjöarna och jämförde detta med redan existerande historiska data med en BACI design. Tvåvägs-ANOVAs användes för att studera effekterna av dammutrivningar på dessa variabler. Det fanns inte tillräckligt med historiska data över P-koncentration eller djur- och växtplankton för att analyseras statistiskt. Jag utförde dock korrelationsanalyser med djur- och växtplankton. I kontrast till min förväntan visad

Ditch cleaning (DC) is recommended by authorities to Swedish landowners to maintain forest productivity after forest harvest by lowering groundwater tables of catchment soils. Knowledge regarding the impact of this practice on surface water quality is limited, and results from previous research vary. Therefore, this master thesis aims to contribute to the knowledge gap by evaluating the impact of DC in relation to the impact of clear-cutting (CC) on ditch water quality. Additionally, I attempt to investigate whether impacts of DC on water quality can be predicted from catchment characteristics. The study was based on synoptic sampling of water chemistry conducted according to a paired design with 25 cleaned and 25 uncleaned reference ditches located along the east coast of mid-Sweden. The sites were further selected to investigate effects of CC forest harvest, with 25 sites located in direct connection to CC areas and 25 sites located in forested areas (unpaired). Sampling was conducted at three different occasions for 25 chemical variables including standard water chemistry, mercury and dissolved greenhouse gases. The results showed that six out of the 25 chemical variables analysed were significantly different between DC and reference (R) sites, namely pH, sulphate (SO4), SUVA254, carbon dioxide (CO2-C), methane (CH4-C), and nitrous dioxide (N2O-N). A lowered groundwater table and more deeper flow paths following DC is suggested as the main cause for the obsereved differences in chemical composition. In contrast, following CC higher concentrations of many chemical variables could be linked to more superficial groundwater flow with many of the variables typically linked to organic matter and nutrients. No interaction effect was observed between treatments, meaning that DC does not enhance the impact of CC. However, CO2-C was significantly lower in DC compared to R, but significantly higher in CC compared to F, indicating that DC counteracts CC in some respects. Fin

197 p., Metal-organic Frameworks (MOFs) are crystalline porous materials built up from metal ions or clusters connected with organic linkers through strong coordination bonds. Among the most outstanding properties their high porosity, large surface areas and tunable structures arise. In the chapters that make up this thesis, the three most relevant points in Materials Science converge: the synthesis, characterization and applicability of MOFs. On the one hand, the different parameters that affect the shape and shape of some well-known MOFs have been studied. In addition, a new characterization technique named Magnetic Sustentation has been developed for the quantification of adsorption processes taking place in solution, which allows a rapid and direct determination of the mass of captured targeted compounds by a paramagnetic MOF. Moreover, the behaviour of the high flexible MIL-88A(Fe) in the removal of short-chain alcohols from water has been theoretically and experimentally studied as well as the synergetic effect between the polymeric PVDF and MIL-88A(Fe) in prepared membranes. Finally, the first scientific effort to explore the true potentials of diverse kinds of MOFs for capturing CO2 in water has been done in order to set a benchmark in the field.

Rock glaciers are the most prominent permafrost-related mountain landforms. This study investigates the effects of the discharge from an intact rock glacier on the hydrological, thermal and chemical dynamics of a high-elevation stream in the NW Italian Alps. Despite draining only 39 % of the watershed area, the rock glacier sourced a disproportionately large amount of discharge to the stream, with the highest relative contribution to the catchment streamflow occurring in late summer - early autumn (up to 63 %). However, ice melt was estimated to be only a minor component to the discharge of the rock glacier, due to its insulating coarse debris mantle. The sedimentological characteristics and internal hydrological system of the rock glacier played a major role in its capability to store and transmit relevant amounts of groundwater, especially during the baseflow periods. Besides the hydrological influence, the cold and solute-enriched discharge from the rock glacier significantly lowered the stream water temperature (especially during warm atmospheric periods) as well as increased the concentrations of most solutes in the stream. Furthermore, in the two lobes forming the rock glacier, different internal hydrological systems and flowpaths, likely driven by different permafrost and ice content, caused contrasting hydrological and chemical behaviours. Indeed, higher hydrological contributions and significant seasonal trends in solute concentrations were found in the lobe with higher permafrost and ice content. Our results highlight the relevance of rock glaciers as water resources, despite the minor ice melt contribution, also suggesting their potential, increasing hydrological importance in the light of climate warming.

Study region: Our study region extends over 450 stream km of the German part of the Elbe River, an ecologically and economically important first order river, between Schöna and Wittenberge. Study focus: Diffuse groundwater born nutrients are major contributors to increased algae growth in rivers, leading to eutrophication with serious consequences for water quality and ecosystem health. Therefore, knowledge of the spatial and temporal dynamics of diffuse groundwater discharge are required since groundwater often remains as a ‘black box’ for the identification of nutrient sources by managers. The multi-method approach, based on the inverse geochemical and tritium modelling, a flux balance, a darcy approach and hydraulic gradients, showed complex spatiotemporal dynamics along the studied reach of the Elbe River. Groundwater inflow was variable but occurred along the entire river. Areas of high groundwater fluxes were located in the upstream mountainous catchment areas and decreasing downstream. New hydrological insights for the region: The multi-method approach provides a blueprint for the assessment of other large river systems. No single method was able to create conclusive results and most other approaches are only applicable in smaller stream systems. First time an estimation of groundwater flux rates, that can be used to quantify matter inputs, was made. In addition, we showed a way to detect and assess the impact of drainage channels in a heterogenous river system.

A laboratory exercise for undergraduates., Assessing the ecological impact of deicing roadways is a well-documented high school and undergraduate toxicology laboratory experiment. Most commonly, this experiment has been done using different concentrations of rock salt (NaCl) as the toxicant/deicer and buttercrunch lettuce seeds for the bioassay. However, as we are becoming a more environmentally conscious society, people, businesses, and city governments have explored substituting NaCl as a deicer for more eco-friendly alternatives, although the impact of these rock salt alternatives have not been well explored in the literature or in the classroom. Thus, the aim of this article is to update the common deicer experiment by having students compare the toxicity of rock salt to that of two different rock salt alternatives (beet salt and calcium chloride, CaCl2). The students then have to provide a recommendation for which deicer to use under different scenarios (for a homeowner, for a business, and for a city) and defend their choices based on an extensive literature search. By designing this experiment to have the students defend their recommendations, they will be utilizing higher-level thinking per Bloom’s Taxonomy, and they will be getting additional hands-on laboratory training in making solutions and performing serial dilutions by examining three deicers rather than just one. Thus, we believe that our update to this laboratory exercise should be considered for faculty interested in having their students conduct toxicology-based laboratory experiments., This project was partially funded through SUNY Discovery Challenge award and the Center for Environmental Medicine and Informatics at SUNY ESF.

The opportunistic pathogen Legionella is the leading cause of reported waterborne disease outbreaks in the United States. Legionella can thrive under the warm, stagnant, low-disinfectant conditions characteristic of premise (i.e., building) plumbing systems, making it challenging to identify effective interventions for its control. Copper (Cu) is a promising antimicrobial that can be dosed directly to water via copper-silver ionization systems or released naturally via corrosion of Cu pipes to help control growth of Legionella and other pathogens. However, prior research has shown that Cu does not always reliably control Legionella and sometimes seems to even stimulate its growth. A deeper understanding of the mechanistic effects of Cu on Legionella, at both pure-culture and real-world scales, is critical in order to inform effective controls for Legionella. The overarching objective of the research embodied by this dissertation was aimed at elucidating the chemical and microbial interactions in premise plumbing that govern efficacy of Cu for Legionella control through a series of complementary bench-, pilot-, and field-scale studies. A critical review and synthesis of the literature identified important knowledge gaps in relation to antimicrobial effects of Cu. In particular, changes in the pH, phosphate corrosion control, and rising levels of natural organic matter (NOM) in distributed water are predicted to be important controlling factors. The type of sacrificial anode rod material employed in water heaters was also identified as an underappreciated factor, which directly affects pH, evolution of hydrogen gas as a microbial nutrient, and release of metals (such as aluminum) that bind copper. Microbiological factors: including growth phase of Legionella (e.g., exponential or stationary), strain-specific Cu tolerance, background microbiome composition, and the possibility that viable but non-culturable (VBNC) Legionella might still cause human disease, were also i

Historically, approximately 25% of Sweden's wetlands have been ditched and drained in favour of agriculture, forestry, infrastructure and peat extraction. Major investments have been made in recent years to recreate the natural and environmental benefits that have been lost. Among other things, this has given rise to Falkenberg municipality's plans to apply for funding to rewet Hakamosse. The purpose of the study is to provide Falkenberg municipality with data through analysis of the current situation regarding water chemical parameters and give suggestions on sampling points and suitable parameters to monitor for Hakamosse. The study is limited to hydrology, water chemistry and greenhouse gases. The water chemistry study was performed by sampling and analysis from three sampling points on five occasions. Scientific information and knowledge gained from other rewetting projects has been collected from scientific literature, reports and semi-structured interviews. The chemical water analysis results show variations between the sampling points and the sampling occasions but with few deviating values. The control program's water chemical monitoring should build on the current situation analysis in this study. Based on the literature study, hydrological measurements should include measurements of groundwater levels and water flow. Greenhouse gas emissions can be measured with instruments or calculated using the IPCC's emission factors. A limiting factor in the implementation of monitoring programs is often the availability of time and financial resources, which often leads to a balance between sampling frequency and the number of sampling points depending on the parameter and method. The results also highlight that a risk analysis is needed as the rewetting of Hakamosse may have a major impact on the surrounding environment., Historiskt har cirka 25% av Sveriges våtmarker dikats och torrlagts till förmån för jordbruk, skogsbruk, infrastruktur och torvtäkter. Stora satsningar har på senare år gjorts för att återskapa de natur- och miljönyttor som gått förlorade. Det har bland annat har gett upphov till Falkenberg kommuns planer på ansökan om bidrag till att återväta Hakamosse. Syftet med studien är att förse Falkenbergs kommun med underlag genom nulägesanalys av vattenkemiska parametrar samt underlag till ett kontrollprogram för Hakamosse. Kontrollprogrammet är avgränsat till hydrologi, vattenkemi och växthusgaser. Den kvantitativa vattenkemiska undersökningen utfördes genom provtagning och analys från tre provtagningspunkter under fem tillfällen. Underlag till utformning av kontrollprogram har insamlats från vetenskaplig litteratur, rapporter och semistrukturerade intervjuer. Det vattenkemiska analysresultatet visar variationer mellan provtagningspunkterna och provtagningstillfällena men med få avvikande värden. Kontrollprogrammets vattenkemiska övervakning bör bygga vidare på nulägesanalysen i denna studie. Baserat på litteraturstudien ska hydrologiska mätningar inkludera mätningar av grundvattennivåer samt vattenflöde. Växthusgasgasavgången kan förslagsvis mätas med provtagningsinstrument eller beräknas med hjälp av IPCC:s emissionsfaktorer. En begränsande faktor vid utformningen av kontrollprogram är ofta tillgången till tidsmässiga och ekonomiska resurser, vilket ofta leder till avvägning mellan provtagningsfrekvens och antalet provtagningspunkter beroende på parameter och metod. Resultatet belyser även att en riskanalys behövs då en återvätning av Hakamosse kan ha en stor påverkan på omgivningen.

Catchment-scale assessments of nitrogen retention and loss rarely account for soil and landscape heterogeneity and are, thus, unable to account for the suite of nitrogen cycling processes that ultimately affect the export of nitrate via stream water. Long-term study at the Hubbard Brook Experimental Forest, NH has generated a unique data set that facilitates spatially explicit examination of interactions among hydrology, soil development, and nitrogen cycling processes. Using high-frequency streamwater chemistry data with intensive subsurface hydrology and solute monitoring, we tracked areas of the catchment that are hydrologically active under different flow conditions to identify the source area of streamwater nitrate. We hypothesize that as the drainage network expands, increasing hydrologic connection to bedrock outcrop-associated soils, streamwater nitrate concentration, and flux at the catchment outlet increase. Most nitrate export (>80%) occurred during high flows when high nitrate, bedrock-controlled areas of the catchment were most connected hydrologically to the drainage network (∼15% of the time). End-member mixing analysis demonstrated that the bedrock-controlled upper part of the catchment influences nitrate concentration at the outlet and contributes most to catchment nitrate export compared to the near-stream soil units and seeps. Most of the time, nitrate at the catchment outlet comes from seeps and the near-stream zone; under high flow conditions, bedrock-controlled hotspots for nitrate production contribute more to export of nitrate. This analysis demonstrates how the source area of streamwater nitrate varies under different flow conditions, suggesting that long-term nitrate dynamics may be driven primarily by a relatively small part of the catchment.

A laboratory exercise for undergraduates., Assessing the ecological impact of deicing roadways is a well-documented high school and undergraduate toxicology laboratory experiment. Most commonly, this experiment has been done using different concentrations of rock salt (NaCl) as the toxicant/deicer and buttercrunch lettuce seeds for the bioassay. However, as we are becoming a more environmentally conscious society, people, businesses, and city governments have explored substituting NaCl as a deicer for more eco-friendly alternatives, although the impact of these rock salt alternatives have not been well explored in the literature or in the classroom. Thus, the aim of this article is to update the common deicer experiment by having students compare the toxicity of rock salt to that of two different rock salt alternatives (beet salt and calcium chloride, CaCl2). The students then have to provide a recommendation for which deicer to use under different scenarios (for a homeowner, for a business, and for a city) and defend their choices based on an extensive literature search. By designing this experiment to have the students defend their recommendations, they will be utilizing higher-level thinking per Bloom’s Taxonomy, and they will be getting additional hands-on laboratory training in making solutions and performing serial dilutions by examining three deicers rather than just one. Thus, we believe that our update to this laboratory exercise should be considered for faculty interested in having their students conduct toxicology-based laboratory experiments., This project was partially funded through SUNY Discovery Challenge award and the Center for Environmental Medicine and Informatics at SUNY ESF.

The effect of copper on Legionella pneumophila in potable water plumbing systems is dependent on its dose and water chemistry. For instance, prior research demonstrated that the presence of aluminum hydroxide from anode rods in water heaters can bind copper and render high doses non-toxic. On this basis it was also hypothesized that iron hydroxide would have similar effects and that lower levels of copper may act as a nutrient encouraging Legionella growth. Here we conducted complementary experiments at bench, microcosm and pilot-scale to evaluate the effect of copper speciation and dose on L. pneumophila. At bench-scale, the addition of 5 mg/L as Fe iron hydroxide to a solution with 1 mg/L copper decreased soluble copper from > 90% down to < 20% at pH 6.5-7. The reduction in soluble copper caused ~3-logs higher L. pneumophila culturability when iron was added with copper when compared to a condition with copper alone. In a 9-month microcosm test using simulated glass water heaters with PEX pipe, a complete range of copper doses (0, 4, 30, 250 and 2000 g/L) were tested in triplicate. Over the first phase of research covered herein, the L. pneumophila levels were low at the four lowest doses of copper, and non-detectable at the highest dose. Moreover, total cell counts were highest at 250 g/L copper, lowest at 2000 g/L copper, and in between these extremes at the lower copper doses. This ongoing experiment will continue for months after this thesis was complete. Pilot-scale experiments were conducted with anode rods removed from tank water heaters, to examine the effects of unprotected corrosion of the steel on iron release and Legionella pneumophila levels in systems with 1) added copper (WH-Cu), 2) copper and phosphate corrosion inhibitor (WH-Cu+PO4-3), 3) phosphate corrosion inhibitor alone (WH-PO4-3) and 4) a control with neither copper nor inhibitor (WH-Control). While there were slight differences in iron between the conditions, the iron concentration in the

The opportunistic pathogen Legionella is the leading cause of reported waterborne disease outbreaks in the United States. Legionella can thrive under the warm, stagnant, low-disinfectant conditions characteristic of premise (i.e., building) plumbing systems, making it challenging to identify effective interventions for its control. Copper (Cu) is a promising antimicrobial that can be dosed directly to water via copper-silver ionization systems or released naturally via corrosion of Cu pipes to help control growth of Legionella and other pathogens. However, prior research has shown that Cu does not always reliably control Legionella and sometimes seems to even stimulate its growth. A deeper understanding of the mechanistic effects of Cu on Legionella, at both pure-culture and real-world scales, is critical in order to inform effective controls for Legionella. The overarching objective of the research embodied by this dissertation was aimed at elucidating the chemical and microbial interactions in premise plumbing that govern efficacy of Cu for Legionella control through a series of complementary bench-, pilot-, and field-scale studies. A critical review and synthesis of the literature identified important knowledge gaps in relation to antimicrobial effects of Cu. In particular, changes in the pH, phosphate corrosion control, and rising levels of natural organic matter (NOM) in distributed water are predicted to be important controlling factors. The type of sacrificial anode rod material employed in water heaters was also identified as an underappreciated factor, which directly affects pH, evolution of hydrogen gas as a microbial nutrient, and release of metals (such as aluminum) that bind copper. Microbiological factors: including growth phase of Legionella (e.g., exponential or stationary), strain-specific Cu tolerance, background microbiome composition, and the possibility that viable but non-culturable (VBNC) Legionella might still cause human disease, were also i

Catchment-scale assessments of nitrogen retention and loss rarely account for soil and landscape heterogeneity and are, thus, unable to account for the suite of nitrogen cycling processes that ultimately affect the export of nitrate via stream water. Long-term study at the Hubbard Brook Experimental Forest, NH has generated a unique data set that facilitates spatially explicit examination of interactions among hydrology, soil development, and nitrogen cycling processes. Using high-frequency streamwater chemistry data with intensive subsurface hydrology and solute monitoring, we tracked areas of the catchment that are hydrologically active under different flow conditions to identify the source area of streamwater nitrate. We hypothesize that as the drainage network expands, increasing hydrologic connection to bedrock outcrop-associated soils, streamwater nitrate concentration, and flux at the catchment outlet increase. Most nitrate export (>80%) occurred during high flows when high nitrate, bedrock-controlled areas of the catchment were most connected hydrologically to the drainage network (∼15% of the time). End-member mixing analysis demonstrated that the bedrock-controlled upper part of the catchment influences nitrate concentration at the outlet and contributes most to catchment nitrate export compared to the near-stream soil units and seeps. Most of the time, nitrate at the catchment outlet comes from seeps and the near-stream zone; under high flow conditions, bedrock-controlled hotspots for nitrate production contribute more to export of nitrate. This analysis demonstrates how the source area of streamwater nitrate varies under different flow conditions, suggesting that long-term nitrate dynamics may be driven primarily by a relatively small part of the catchment.

Study regionVltava River basin, South Bohemian Region of the Czech Republic, Central EuropeStudy focusTo understand the dynamics of nutrients (nitrogen, phosphorus, and organic carbon) in streams, we combined hydrometeorological, hydrochemical and isotopic data (stable water and nitrate isotopes) from three catchments with different predominant land-use effects (forest, agricultural and settlement).New hydrological insights for the study regionOur study underlines that current climate change and associated hydrological changes, such as decrease in flow, play an important role in the transport and dynamics of nutrients in the catchment. We have found that due to the different origins and pathways, individual nutrients had diverse behaviour patterns in streams and responded differently to changing climate. Hydrological patterns in streams became clear when systematic and continuous monitoring under a changing climate was applied, highlighting the need for such data to better understand the impact of hydrological drivers, particularly for long-term dynamics. In three studied catchments, streamflow showed a decreasing trend in line with rising air temperature, declining snow cover and increasing evapotranspiration. Time series analyses of nitrate concentrations revealed decreasing trends, whereas dissolved organic carbon increased in all catchments regardless of land use. Long-term trends of total phosphorus concentrations were positive in anthropogenically impacted streams. Stable nitrate isotopes indicated distinct nitrate sources and processes, but also their seasonality in relation to hydrological patterns and land use.

Water chemistry and its ecological implications have been extensively investigated in temperate high-mountain lakes because of their role as sentinels of global change. However, few studies have considered the drivers of water chemistry in tropical mountain lakes underlain by volcanic bedrock. A survey of 165 páramo lakes in the Cajas Massif of the Southern Ecuador Andes identified 4 independent chemical variation gradients, primarily characterized by divalent cations (hardness), organic carbon, silica, and iron levels. Hardness and silica factors showed contrasting relationships with parent rock type and age, vegetation, aquatic ecosystems in the watershed, and lake and watershed size. Geochemical considerations suggest that divalent cations (and related alkalinity, conductivity, and pH) mainly respond to the cumulative partial dissolution of primary aluminosilicates distributed throughout the subsurface of watersheds, and silica and monovalent cations are associated with the congruent dissolution of large amounts of secondary aluminosilicates localized in former hydrothermal or tectonic spots. Dissolved organic carbon was much higher than in temperate high-mountain lakes, causing extra acidity in water. The smaller the lakes and their watersheds, the higher the likelihood of elevated organic carbon and metals and low hardness. The watershed wetland cover favored metal levels in the lakes but not organic carbon. Phosphorus, positively, and nitrate, negatively, weakly correlated with the metal gradient, indicating common influence by in-lake processes. Overall, the study revealed that relatively small tropical lake districts on volcanic basins can show chemical variation equivalent to that in large mountain ranges with a combination of plutonic, metamorphic, and carbonate rock areas

Historically, approximately 25% of Sweden's wetlands have been ditched and drained in favour of agriculture, forestry, infrastructure and peat extraction. Major investments have been made in recent years to recreate the natural and environmental benefits that have been lost. Among other things, this has given rise to Falkenberg municipality's plans to apply for funding to rewet Hakamosse. The purpose of the study is to provide Falkenberg municipality with data through analysis of the current situation regarding water chemical parameters and give suggestions on sampling points and suitable parameters to monitor for Hakamosse. The study is limited to hydrology, water chemistry and greenhouse gases. The water chemistry study was performed by sampling and analysis from three sampling points on five occasions. Scientific information and knowledge gained from other rewetting projects has been collected from scientific literature, reports and semi-structured interviews. The chemical water analysis results show variations between the sampling points and the sampling occasions but with few deviating values. The control program's water chemical monitoring should build on the current situation analysis in this study. Based on the literature study, hydrological measurements should include measurements of groundwater levels and water flow. Greenhouse gas emissions can be measured with instruments or calculated using the IPCC's emission factors. A limiting factor in the implementation of monitoring programs is often the availability of time and financial resources, which often leads to a balance between sampling frequency and the number of sampling points depending on the parameter and method. The results also highlight that a risk analysis is needed as the rewetting of Hakamosse may have a major impact on the surrounding environment., Historiskt har cirka 25% av Sveriges våtmarker dikats och torrlagts till förmån för jordbruk, skogsbruk, infrastruktur och torvtäkter. Stora satsningar har på senare år gjorts för att återskapa de natur- och miljönyttor som gått förlorade. Det har bland annat har gett upphov till Falkenberg kommuns planer på ansökan om bidrag till att återväta Hakamosse. Syftet med studien är att förse Falkenbergs kommun med underlag genom nulägesanalys av vattenkemiska parametrar samt underlag till ett kontrollprogram för Hakamosse. Kontrollprogrammet är avgränsat till hydrologi, vattenkemi och växthusgaser. Den kvantitativa vattenkemiska undersökningen utfördes genom provtagning och analys från tre provtagningspunkter under fem tillfällen. Underlag till utformning av kontrollprogram har insamlats från vetenskaplig litteratur, rapporter och semistrukturerade intervjuer. Det vattenkemiska analysresultatet visar variationer mellan provtagningspunkterna och provtagningstillfällena men med få avvikande värden. Kontrollprogrammets vattenkemiska övervakning bör bygga vidare på nulägesanalysen i denna studie. Baserat på litteraturstudien ska hydrologiska mätningar inkludera mätningar av grundvattennivåer samt vattenflöde. Växthusgasgasavgången kan förslagsvis mätas med provtagningsinstrument eller beräknas med hjälp av IPCC:s emissionsfaktorer. En begränsande faktor vid utformningen av kontrollprogram är ofta tillgången till tidsmässiga och ekonomiska resurser, vilket ofta leder till avvägning mellan provtagningsfrekvens och antalet provtagningspunkter beroende på parameter och metod. Resultatet belyser även att en riskanalys behövs då en återvätning av Hakamosse kan ha en stor påverkan på omgivningen.

В статье рассмотрено современное состояние вопроса о выявлении изменений, происходящих в воде в результате различных физических воздействий, приведена классификация методов индикации, проанализированы их главные достоинства и недостатки, обсуждены наиболее часто применяемые на практике индикаторы и оценена перспективность их дальнейшего использования для контроля качества воды. Приведены необходимые сведения для проведения лекционных и практических занятий по химии воды, посвященных затронутой теме., The article discusses the current state of the issue about identifying changes in water as a result of various physical influences. The paper provides a classification of indication methods, analyzes their main advantages and disadvantages, discusses the most commonly used indicators, and assesses the prospects of their further usage for water quality control. The necessary information for lecturing and practical trainings on the water chemistry is given.

403 p., Ura bizitzarako baliabide sozioekonomiko urria eta ezinbestekoa da. Baliabide preziatu honek gero eta eskaera handiagoa du, eta, aldi berean, mundu mailako arazo bihurtu dira haren eskasia eta poluzioa. Hori dela eta, ezinbestekoa da ur-baliabideak era estrategiko eta jasangarrian kudeatzea eta tratatzea. Hondakin-uretan dauden poluitzaileen aniztasuna handia denez, industriako hondakin-uren poluzio-kasu adierazgarrienak, bereziki 4-klorofenola, fenola, anilina eta bentzotiazola, eta etxeetako hondakin-ureei arreta berezia jarriz kezka sortzen duten kutsatzaileei, hala nola farmazia-produktuak, norberaren zaintzarako produktuak eta disruptore endokrinoak, besteak beste aztertu dira lan honetan, oxidazio-teknologia aurreratu esanguratsuenak eta egokienak izan daitezkeenak erabiliz, UV/H2O2, fotokatalisi heterogeneoa, ozonizazio katalitikoa eta ultrasoinuak, aurkezten dira lan honetan. Horretarako, prozesu fotokimikoen ezagutzan eta ozonoan oinarritutako prozesu ez-fotokimikoen ezagutzan sakondu da, eta tratamendu-teknologia eraginkorrenak garatzeko abantailatsuenak diren kondizioak eta konfigurazioak aztertu dira, haien ereduak lortzeko. Horrez gain, ekipamendu eta material katalitiko berriak diseinatu dira, prozesu fotokatalitikoetan eta ozonoan oinarritutako teknologietan erabiltzeko, oxidazio-prozesu aurreratuen intentsitatea indartzeko asmoz, eta industriako eta etxeetako hondakin-ur adierazgarrietan aplikatzeko.

The water quality of urban runoff is significant to arid and semiarid regions, such assouthern Arizona, which count urban runoff among the limited renewable resources for a continued water supply. Despite the essential nature of this resource, the hydrochemical evolution of urban runoff over the course of a storm and a rainy season overall is less well understood. Improved understanding would help researchers and resource managers alike in addressing water quality issues. Nitrogen species constitute a high priority water quality concern. This research addresses the evolution and transport of nitrogen during eight individual storm events that occurred over three summer monsoon seasons (2016-2018) in an urban catchment in the semiarid city of Tucson, Arizona. Hysteretic storm behavior was analyzed for the solute concentrations of nitrogen species and a conservative tracer (Cl-) to provide insight into the catchment processes between the upstream and downstream sampling locations. Of the 94 performed analyses, 49 hysteresis analyses display clockwise behavior. Thirty-six analyses result in counterclockwise loops, and 9 are linear (i.e., no hysteresis). All 9 of the linear responses are total organic nitrogen (TON). In general, the upstream site has a more consistent clockwise response, and the downstream site has a more varied response among the measured solutes. The results indicate that solute flushing is the primary response of the gravel lined urban wash during monsoon events, with some complexity in the response resulting from limited biogeochemical processing and/or additional runoff/solute sources resulting from the managed nature of the watershed. The linear TON response of many storms indicates that the nitrogen species moving through the system are inorganic. The downstream site displays more varied hysteresis responses due to the presence of a concrete lined section of the channel under a two- lane residential road, which increases the discharge rate and alt

403 p., Ura bizitzarako baliabide sozioekonomiko urria eta ezinbestekoa da. Baliabide preziatu honek gero eta eskaera handiagoa du, eta, aldi berean, mundu mailako arazo bihurtu dira haren eskasia eta poluzioa. Hori dela eta, ezinbestekoa da ur-baliabideak era estrategiko eta jasangarrian kudeatzea eta tratatzea. Hondakin-uretan dauden poluitzaileen aniztasuna handia denez, industriako hondakin-uren poluzio-kasu adierazgarrienak, bereziki 4-klorofenola, fenola, anilina eta bentzotiazola, eta etxeetako hondakin-ureei arreta berezia jarriz kezka sortzen duten kutsatzaileei, hala nola farmazia-produktuak, norberaren zaintzarako produktuak eta disruptore endokrinoak, besteak beste aztertu dira lan honetan, oxidazio-teknologia aurreratu esanguratsuenak eta egokienak izan daitezkeenak erabiliz, UV/H2O2, fotokatalisi heterogeneoa, ozonizazio katalitikoa eta ultrasoinuak, aurkezten dira lan honetan. Horretarako, prozesu fotokimikoen ezagutzan eta ozonoan oinarritutako prozesu ez-fotokimikoen ezagutzan sakondu da, eta tratamendu-teknologia eraginkorrenak garatzeko abantailatsuenak diren kondizioak eta konfigurazioak aztertu dira, haien ereduak lortzeko. Horrez gain, ekipamendu eta material katalitiko berriak diseinatu dira, prozesu fotokatalitikoetan eta ozonoan oinarritutako teknologietan erabiltzeko, oxidazio-prozesu aurreratuen intentsitatea indartzeko asmoz, eta industriako eta etxeetako hondakin-ur adierazgarrietan aplikatzeko.

Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community. © Copyright © 2021 Cherbunina, Karaevskaya, Vasil’chuk

Nitrate pollution in groundwater is a serious problem in Shimabara Peninsula, Nagasaki, Japan. A better understanding of the hydrogeochemical evolution of groundwater in vulnerable aquifers is important for health and environment. In this study, groundwater samples were collected at 12 residential and 57 municipal water supply wells and springs in July and August 2018. Nitrate (NO3-N) concentration at eight sampling sites (12%) exceeded Japanese drinking water standard for NO3 + NO2-N (10 mg L-1). The highest nitrate concentration was 19.9 mg L-1. Polluted groundwater is distributed in northeastern, northwestern, and southwestern areas, where land is used for intensive agriculture. Correlation analysis suggests that nitrate sources are agricultural fertilizers and livestock waste. Dominant groundwater chemistry is (Ca+Mg)-HCO3 or (Ca+Mg)-(SO4+NO3) type. Groundwater with higher nitrate concentration is of (Ca+Mg)-(SO4+NO3) type, indicating nitrate pollution affecting water chemistry. Principal component analysis extracted two important factors controlling water chemistry. The first principal component explained dissolved ions through water-rock interaction and agricultural activities. The second principal component explained cation exchange and dominant agricultural effects from fertilizers. Hierarchical cluster analysis classified groundwater into four groups. One of these is related to the dissolution of major ions. The other three represent nitrate pollution., Water, 13(4), art.no.426; 2021

Precipitation of solids in plumbing systems (i.e., scaling) is a major problem in both traditional tank (electric and gas) and tank-less building hot water systems. Scaling can cause energy inefficiencies, flow reduction, pressure loss, and erosion corrosion damage. Consumers are also concerned with unsightly soap scum, cloudy water, discolored glassware, and failing infrastructure including appliances and fixtures. There are many treatments available that claim to ameliorate scaling problems, and several efforts have been made to develop standardized test protocols to verify and quantify their performance. This work critically evaluated previous testing efforts and revealed limitations in terms of reproducibility and a need to measure all key aspects of scale deposition including quantity, location, aesthetic and other issues. A Standardized Scaling Test Protocol (SSTP) was conceived and vetted to address these deficiencies and measure key parameters of calcium carbonate scaling throughout a model premise plumbing system, while using a synthesized test water that could provide reproducible results in any laboratory. This synthetic water and methodology was able to produce significant scaling in a model hot water system within the targeted 5-day experimental time frame. The average amount of scale recovered for the triplicate control tests (with no scale reduction device) was 25.1 grams of calcium carbonate with a 95% confidence interval of 20.3-29.8 grams of calcium carbonate. The approach also worked in recreating scaling in natural waters and was used to verify the performance of a wide array of scale reduction technologies including cation exchange softeners, electrochemical deionization, physical magnets or electric field generators, media induced precipitation, sacrificial media (phosphate), and sacrificial media (citric acid). While calcium carbonate precipitation within a water distribution system is generally undesirable; it was recently discovered that cal

The “Fonts del Montseny Project” has chemically and minerally analyzed more than two hundred sources from the Montseny Biosphere Reserve. To check the multivariable influence on water, during 2020 a research was carried out at the School of Engineering of Barcelona East, to study a statistical treatment with a view to finding similarities and differences of the analyzed parameters. The proposed analyzes have been able to find out hydro-mineralogical differences in the waters of the springs of each area of the Montseny and it has been verified that the developed geographical areas have been selected correctly by differentiating between North, East and West. The analyses of the main components and clusters have determined the parameters that distinguish each zone. The western Montseny has a high mineralization due to the large amount of limestone present and also has bicarbonate and calcium waters of high mineral content. The eastern and northern areas of the Montseny have weak mineralogical waters. Their differentiation has been made by the altitude of the samples., Objectius de Desenvolupament Sostenible::6 - Aigua Neta i Sanejament, Postprint (published version)

Trace metals found in the calcified structures of fish (i.e. otolith, scales and vertebrae) serve as proxies for the ambient water composition at the time of mineralization, and these trace metals are increasingly used as a tool for assessing population structure and the migratory patterns of fish. However, the appropriate scale (e.g. resolution) for such applications can be uncertain because of a poor understanding of the spatiotemporal variations of metal-to-calcium ratios (Me:Ca) in the studied watersheds. This study aims to assess Me:Ca spatiotemporal variability within the St. Lawrence River and nine major tributaries and evaluate the ability of random-forest models to correctly identify rivers on the basis of their elemental composition. We tested the influence of daily discharge on four measured ratios (Sr:Ca, Ba:Ca, Mg:Ca and Mn:Ca) to document local and regional trace element sources and dynamics. The four element ratios displayed a low spatiotemporal variation, reflecting a marked stability over time. We observed that most element- and tributary-specific concentration–discharge relationships were either not significant or showed a weak influence, thereby confirming a stable point source dynamic. The classification performance based on a four-element model (Sr:Ca, Ba:Ca, Mg:Ca and Mn:Ca) produced a classification accuracy of 92.5%, which correspond to a small decrease of accuracy compared to the full model (25 elements, 96.6% of correct classification). A classification based on two elements (Sr:Ca and Ba:Ca) produced a lower classification accuracy (72.6%). Classification errors related mainly to tributaries in close proximity, a problem tempered by grouping these geochemically similar watersheds. Our results show that surveys of the elemental fingerprint of regional tributaries within a given region can provide critical information to determine the appropriate scale (tributary or watershed) for trace metal analysis of the hard-calcified parts of fish.

403 p., Ura bizitzarako baliabide sozioekonomiko urria eta ezinbestekoa da. Baliabide preziatu honek gero eta eskaera handiagoa du, eta, aldi berean, mundu mailako arazo bihurtu dira haren eskasia eta poluzioa. Hori dela eta, ezinbestekoa da ur-baliabideak era estrategiko eta jasangarrian kudeatzea eta tratatzea. Hondakin-uretan dauden poluitzaileen aniztasuna handia denez, industriako hondakin-uren poluzio-kasu adierazgarrienak, bereziki 4-klorofenola, fenola, anilina eta bentzotiazola, eta etxeetako hondakin-ureei arreta berezia jarriz kezka sortzen duten kutsatzaileei, hala nola farmazia-produktuak, norberaren zaintzarako produktuak eta disruptore endokrinoak, besteak beste aztertu dira lan honetan, oxidazio-teknologia aurreratu esanguratsuenak eta egokienak izan daitezkeenak erabiliz, UV/H2O2, fotokatalisi heterogeneoa, ozonizazio katalitikoa eta ultrasoinuak, aurkezten dira lan honetan. Horretarako, prozesu fotokimikoen ezagutzan eta ozonoan oinarritutako prozesu ez-fotokimikoen ezagutzan sakondu da, eta tratamendu-teknologia eraginkorrenak garatzeko abantailatsuenak diren kondizioak eta konfigurazioak aztertu dira, haien ereduak lortzeko. Horrez gain, ekipamendu eta material katalitiko berriak diseinatu dira, prozesu fotokatalitikoetan eta ozonoan oinarritutako teknologietan erabiltzeko, oxidazio-prozesu aurreratuen intentsitatea indartzeko asmoz, eta industriako eta etxeetako hondakin-ur adierazgarrietan aplikatzeko.

The water quality of urban runoff is significant to arid and semiarid regions, such assouthern Arizona, which count urban runoff among the limited renewable resources for a continued water supply. Despite the essential nature of this resource, the hydrochemical evolution of urban runoff over the course of a storm and a rainy season overall is less well understood. Improved understanding would help researchers and resource managers alike in addressing water quality issues. Nitrogen species constitute a high priority water quality concern. This research addresses the evolution and transport of nitrogen during eight individual storm events that occurred over three summer monsoon seasons (2016-2018) in an urban catchment in the semiarid city of Tucson, Arizona. Hysteretic storm behavior was analyzed for the solute concentrations of nitrogen species and a conservative tracer (Cl-) to provide insight into the catchment processes between the upstream and downstream sampling locations. Of the 94 performed analyses, 49 hysteresis analyses display clockwise behavior. Thirty-six analyses result in counterclockwise loops, and 9 are linear (i.e., no hysteresis). All 9 of the linear responses are total organic nitrogen (TON). In general, the upstream site has a more consistent clockwise response, and the downstream site has a more varied response among the measured solutes. The results indicate that solute flushing is the primary response of the gravel lined urban wash during monsoon events, with some complexity in the response resulting from limited biogeochemical processing and/or additional runoff/solute sources resulting from the managed nature of the watershed. The linear TON response of many storms indicates that the nitrogen species moving through the system are inorganic. The downstream site displays more varied hysteresis responses due to the presence of a concrete lined section of the channel under a two- lane residential road, which increases the discharge rate and alt

Många vattenkraftverk i Sverige är uppbyggda med dammar som är designade för att läcka en viss mängd vatten baserat på materialet de är byggda med. Flödet av läckagevattnet mäts för att säkerställa dammens funktion, men vid många kraftverksdammar är mätbrunnarna och dräneringsrör fyllda med en rödbrun sörja som kallas rödslam. Rödslammet gör det omöjligt att mäta flödet korrekt, och kan i värsta fall sätta igen dränagesystemet helt och hållet. Ett tidigare examensarbete fastställde att specifika järnbakterier var ansvariga för rödslammet, bakterier som utvinner energi genom att oxidera vattenlösligt tvåvärt järn i vattnet till olösligt trevärt järn. För att bekämpa uppbyggnaden av järnbakterierna analyserades föreslagna lösningar från studier om andra branscher som också har problem med rödslam i dränagesystemen. Lösningar som förändrar syrenivåerna, sprider ut kalk, använder inorganiska eller organiska baktericider samt mekaniska lösningar analyserades baserat på deras effektivitet och miljöpåverkan jämfört med den lösning som kraftverk applicerar idag, spolning med högtryckstvätt. Den mest lämpliga lösningen var att sprida ut sågspån och bark från barrträd i dräneringsdiken vid kraftdammen, då denna metod har dokumenterad effekt inom jordbrukssektorn och studier visar att den har liten miljöpåverkan. Dessutom är metoden kostnadseffektiv då sågspån är en restprodukt från skogsbruket. Genom att kombinera denna lösning med spolning när det behövs finns det goda chanser att man kan säkerställa att flödesmätningarna fungerar samt minska den totala kostnaden för underhållet., Many hydroelectric plants in Sweden are built using dams that are designed to leak a certain amount of water based on the material they are built with. The flow of the leakage water is measured to ensure proper function of the dams, but at several dams the measuring wells and drainage pipes are clogged with a red-brown sludge called Iron Ochre. The build-up of iron ochre is caused by specific bacteria that oxidize soluble iron(II) in the water to insoluble iron(III). The iron ochre forms a thick sludge that can make flow measurements impossible, and at worst can clog up the drainage system completely. In this thesis, methods to combat the growth of bacteria were analyzed based on their efficiency and environmental impact with the aim of finding methods that can be applied at Swedish hydroelectric dams. The methods include changing the oxygen levels, applying lime, using inorganic or organic bactericides and physical solutions. The methods were compared to the existing solution of high-pressure washing with water. According to the evaluation, the most well-suited solution is to apply conifer sawdust and bark in the drainage ditches surrounding the dams. This solution has a documented effect in the agricultural sector and there are studies that suggest it has a low environmental impact. Sawdust and bark are waste products from logging industries, making the solution cost-efficient as well. By combining this solution with high-pressure washing when necessary, it is possible to ensure that proper flow measurements can be taken while decreasing the overall cost of maintenance.

La liofilització és un procés mitjançant el qual s’aconsegueix que un producte, normalment alimentari o sanitari, perdi la seva aigua, de manera que pugui conservar-se més temps. Això sense perdre les seves propietats i de forma que quan es torni a aportar aigua, aquest producte quedi com estava al principi. En aquest treball no només s’explica en què consisteix la liofilització, sinó també en què es basa, com es mesura l’activitat d’aigua, per a què serveix i algunes de les seves aplicacions, fent mencions a articles actuals. A la part pràctica d’aquest projecte, es posarà en marxa un liofilitzador Telstar Cryodos i es liofilitzaran diferents mostres alimentàries per tal de comprovar que l’aparell funciona de forma correcta., Freeze-drying is a process by which a product, usually food or sanitary, loses its water, so that it can be stored longer. All of this without losing its properties and the condition that when water is returned, this product stay as it was at the beginning. This paper not only explains what lyophilization is, but also in which is based on, how the amount of water is checked, for what is used for and some of its applications, mentioning current articles. In the practical part of this project, a Telstar Cryodos lyophilizer will be set up and different food samples will be lyophilized in order to check that the device is working properly.

During recent decades, increasing anthropogenic activities have affected natural ionic composition, including the strongest and most common relationship between ionic concentrations in the majority of natural global freshwaters, i.e., the Ca2+-ANC (acid neutralizing capacity) equilibrium. Using long-term monitoring data and MAGIC modelling, we evaluated effects of major present environmental stressors (synthetic fertilizers, liming, acidic deposition, forest disturbances, and climate change) on the Ca2+-ANC equilibrium. We evaluated the effects for three different types of terrestrial ecosystems, a circumneutral lowland agricultural catchment, two acid sensitive mountain forest catchments differing in forest health, and one acid sensitive alpine catchment. All catchments are in a region with the world-largest changes in fertilizing rates and acidic deposition in the 20th century, with increasing impacts until the late 1980s, and their subsequent abrupt, dramatic decreases. These strong changes resulted in a substantial disruption, followed by continuing re-establishment of the Ca2+-ANC relationship in all study waters. The shape of the disruption and the following re-establishment of its new value were dependent on the intensity, duration, and combination of stressors, as well as on catchment characteristics (bedrock composition, soil amount and composition, vegetation status, and hydrology). We conclude that a new equilibrium may deviate from its natural value due to the (1) legacy of fertilizing, acidic deposition and liming, affecting the soil Ca(2+ )pools, (2) forest disturbances and management practices, and (3) climate change. (C) 2020 Elsevier B.V. All rights reserved.

Water molecule contains one oxygen and two hydrogen atoms, making it a potential oxygen and hydrogen source. Electrocatalytic organic reduction and oxidation using water as oxygen and/or hydrogen donors provide an environmentally friendly and sustainable strategy to replace traditional chemical-driven stoichiometric reactions that use sacrificial reagents. Furthermore, the development of electrochemical synthesis provides a potential application for low tension photoelectricity, which is not cost-effective during boosted voltage and application. In the last decade, electrocatalytic redox reactions of organic molecules in aqueous media had shown progress owing to the development of electrode materials and water-splitting technology. This paper highlights several electrocatalytic systems and corresponding mechanisms for both hydrogenation and oxidative transformation of representative compounds. The activation process of protons and water on the working electrode surface has received special focus. Furthermore, paired electrolysis using water as the oxygen and hydrogen source has been demonstrated. This paired system combines hydrogenation and oxidation half-reactions in one cell using water as the hydrogen and oxygen source, resulting in high atomic and electron utilization rates., QC 20201217

[EN] We first report the systematic control of the reactivity of H2O vapor in metal-organic frameworks (MOFs) with Pt nanocrystals (NCs) through ligand functionalization. We successfully synthesized Pt NCs covered with a water-stable MOF, UiO-66 (Pt@UiO-66), having different metal ions or functionalized ligands. The ligand functionalization of UiO-66 significantly affected the catalytic performance of the water-gas shift reaction, and the replacement of Zr4+ ions with Hf4+ ions in UiO-66 had no impact on the catalytic activity. The introduction of a -Br group lowered the reactivity of Pt@UiO-66 by nearly half, whereas the substitution of -Br with a -Me2 group triply enhanced the activity. The origin of the enhanced catalytic activity was found to be the change in H2O activity in the UiO-66 pores by the ligand functionalization, which was investigated using H2O sorption, solid-state NMR, X-ray photoelectron spectroscopy, and in situ IR measurements. This work opens a new prospect to develop MOFs as a platform to activate H2O.