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Im Zuge der Anfänge der Verhaltenstherapie (VT) und der “kognitiven Wende” wurde der aktiven Beziehungsgestaltung und damit verbundenen Faktoren zunächst nur zweitrangig Beachtung geschenkt, obwohl die Bedeutung der Beziehung zwischen Therapeut und Patient auch in der VT bereits relativ früh erkannt wurde. Seitdem hat sich die VT substanziell weiterentwickelt. Insbesondere die aktive Gestaltung der therapeutischen Beziehung in Abhängigkeit verschiedener Variablen ist mittlerweile fester Bestandteil einer jeden VT. In dieser Übersichtsarbeit werden Konzepte der Beziehungsgestaltung dargestellt, welche der VT zugerechnet und im Rahmen der Ausbildung im deutschsprachigen Raum gelehrt werden. Fokussiert wird auf folgende drei Ansatzpunkte: Die Ausrichtung der Beziehung an (1) Therapiephasen, (2) Bedürfnissen, Motiven und Erwartungen sowie (3) frühen traumatisierenden Bezie­hungserfahrungen. Die aktuelle Studienlage legt nahe, dass pauschalisierte Handlungsempfehlungen zur aktiven Gestaltung der therapeutischen Beziehung zu kurz greifen. Ausgehend von der individuellen Problematik des einzelnen Patienten wird die Realisierung der therapeutischen Beziehung im Sinne einer differentiellen Beziehungsgestaltung beschrieben und diskutiert.

International audience; The knowledge of the sources of base cations in stream water is a prerequisite to assess potential effects of changing environmental conditions such as changing rainfall, weathering or groundwater flows on cation export with stream water. This study use stable Mg isotopes to identify potential sources in the well-studied catchment of Krycklan located on gneissic bedrock covered by quaternary sediments in Sweden. Samples were collected from open filed rain, throughfall, stream, soil, rock and litterfall. The δ26Mg values of these samples was determined and the contributions of different sources to Mg fluxes in the stream were determined from the variation of the Mg isotope and Sr / Mg ratios.The results show an overall variation of 1.10‰ between all samples. In addition, Magnesium isotope ratios varied little in the streamwater and in soil solution, except during snowmelt periods during which a large portion of the annual runoff occurs. Magnesium in the streamwater is explained as a mixture of three pools (open field rain, soil solution and groundwater) with the latter two influenced by catchment processes. Outside the snowmelt period, Mg in streamwater mainly derived from the groundwater, assumed to be mineral weathering signature in this catchment, with a contribution ranging from 12 to 63% to Mg fluxes. Open field rain dominates Mg fluxes in streamwater during spring flood (0 to 78%) and may contribute significantly during larger summer and autumn rainfall events. Soil solution input to streamwater range from 16 to 59% of Mg fluxes in streamwater. Our results demonstrate that δ26Mg values together with Mg concentrations and Sr/Mg ratios can be used to constrain the Mg sources of stream water and quantify weathering release rates.

Concentrations of lanthanides (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Lu) were measured in soils and soil water from a hillslope transect in the Krycklan catchment in northern Sweden. Soil water was collected at different depths and at different distances from the draining stream – from the uphill Podzol to the peaty riparian zone – throughout the course of a year. Combined with soil profiles from the same sites this provided a comprehensive dataset to study the fractionation and transport of lanthanides from boreal forest soils to streams. The soil water was characterised by high concentrations of lanthanides in the riparian zone, more than an order of magnitude higher than in the uphill mineral soil, and when normalised against local unweathered till the soil water exhibited distinctly negative Eu anomalies, particularly in deeper soil layers. The soil samples displayed both positive and negative Eu anomalies, but positive Eu anomalies were primarily associated with strongly weathered soils, whereas negative soil Eu anomalies were observed in organic soils at depths were large amounts of lanthanides are transported towards the stream. Since reduction of Eu seems unlikely to occur in this transect, we propose that the Eu anomalies in soils and soil water are caused by the partial occurrence of Eu in more weathering-resistant minerals than the other lanthanides. Based on the collected data and the hydrological and biogeochemical understanding of the studied transect we therefore propose a conceptual model for how Eu anomalies arise and how they can be used to interpret the Holocene transport and accumulation of lanthanides in soils. The results suggest that Eu anomalies have the potential to become a powerful tracer for studying weathering and soil development.

Carbon dioxide is known as an important agent in aqueous media to induce chemical attack on building materials. The leaching behavior of pea gravels, which are used as backfill material in continuous tunneling, is not entirely resolved until now. Evaluating the durability and economical advantage of individual backfill materials requires a proper experimental design to survey the dissolution reactions and to develop a useful modelling approach to calculate dissolution for carbonate bearing pea gravels. In this study a combined flow through reactor unit was developed, where conditions for chemical attack on gravel material can be simulated by changing flow rate and/or CO2 partial pressure. The addition of CO2(gas) was adjusted by pHstat conditions. Solution chemistry was monitored in-situ and by analyzing samples throughout experimental runs. For 5 natural gravels with different calcite(dolomite)/quartz ratios, the dissolution rates of Ca2+ for carbonates (RCa_cc; normalized on exposed carbonate surfaces) were found to reflect mineralogy, carbonate content, flow rates and thus saturation state conditions. RCa_dol values for dolomite are significantly lower (10−12

Zusammenfassung Bei einem nicht einwilligungsfähigen Patienten mit schwerer psychischer Störung besteht zwar häufig die Notwendigkeit einer raschen Diagnostik und Therapie, das Symptombild führt jedoch nicht selten zu einer Ablehnung solcher Maßnahmen. In der täglichen Praxis stellt sich dann die Frage, inwieweit der geäußerte Wille des Patienten die Behandlungsschritte vorgibt oder ob eine Entscheidung gegen den Willen des Patienten medizinisch sinnvoll, ethisch vertretbar oder sogar geboten und rechtlich zulässig ist. Autoimmune Enzephalitiden – wie die N‑Methyl-D-Aspartat-Rezeptor(NMDAR)-Enzephalitis – sind aufgrund ihrer relativen Häufigkeit, vielgestaltigen Symptomatik und guten Therapierbarkeit neuerdings wichtige Differenzialdiagnosen, da die zugrunde liegenden Autoantikörper besonders häufig zu organischen Psychosen führen. Am Beispiel eines komplexen Falles einer Patientin mit im Verlauf gesicherter NMDAR-Enzephalitis erläutern wir die praxisrelevanten ethisch-juristischen Abwägungen von der initialen invasiven Diagnostik bis zur Unterbringung und Zwangsbehandlung. Die Bewertung soll konkrete Hilfestellungen geben, die Autonomie des Patienten zu respektieren, potenzielle Widersprüche zwischen dem freien Willen und dem geäußerten Willen zu ermessen, individuelle ärztliche Überzeugungen (hinsichtlich Autonomiefähigkeit und Zwangsbehandlung) anhand der Rechtslage zu überprüfen, die Indikation für eine vorübergehende Behandlung gegen den natürlichen Willen zu stellen, Analogien zu anderen schweren Hirnerkrankungen herzustellen und erfolgreich gegenüber dem Betreuungsgericht zu argumentieren.

Conventional drinking water treatment is inefficient in removing a large fraction of known organic micropollutants (OMPs). Therefore more efficient treatment approaches are needed to limit exposure to OMPs via drinking water. Here, the OMP removal performance of a combination of ozonation/no ozonation and two types of granular activated carbon (GAC) was tested in a one-year pilot-scale study, alongside a study of full-scale treatment. The raw water was lake water with low ambient concentrations of OMPs. In total, 29 of 99 targeted OMPs (per- and polyfluoroalkyl substances (PFASs), pharmaceuticals and other OMPs) were detected (mean n-ary sumation OMPs = 57 +/- 16 ng L-1). Only a few OMPs were consistently removed in the full-scale process, while ozonation in the pilot experiment effectively removed 72% of detected compounds to levels

The removal of per- and polyfluoroalkyl substances (PFASs) presents a challenge for drinking water providers. Guidelines for PFAS concentrations in final drinking water are regularly updated to ever-decreasing values, and conventional drinking water treatment plants are not designed to remove PFASs. Currently, the most frequently used removal technique, adsorption to granular activated carbon (GAC), is often considered challenging. High-pressure membranes, such as nanofiltration (NF), have been shown to remove PFASs efficiently. However, the creation of a waste stream comprised of at least 10% of the feedwater volume is recognized as a major drawback of this technique. In this study, a NF pilot plant was operated at a drinking water treatment plant in the city of Uppsala, Sweden, for six months. NF removed up to >98% of PFASs and fulfilled other water quality targets, such as the removal of uranium-238, dissolved organic carbon (DOC), and mineral hardness from the raw water. The concentrate from the pilot plant was treated with two different GAC materials and two different anion exchange (AIX) resins in column tests, where the superior performance of AIX over GAC was observed in terms of PFAS removal. PFAS adsorption curves for GAC were found to superimpose each other for the two water types if normalized to the specific throughput of DOC. The application of the freely available PHREEQC model revealed improvement possibilities in terms of resin properties. A cost analysis using the column test results compared GAC filtration to the combination of NF with adsorption materials. Treatment costs were found to be largely dependent on the PFAS drinking water treatment goals and concentrate discharge requirements, which highlight the economic consequences of prevailing guidelines for drinking water and discharge to the environment. The results of this study provide both the scientific community as well as drinking water providers with important insights into the application of NF for PFAS removal during drinking water treatment as well as that mechanistic and economic aspects of NF treatment and the management of the resulting concentrate.

The Arctic terrestrial environment harbors a complex mosaic of mercury (Hg) and carbon (C) reservoirs, some of which are rapidly destabilizing in response to climate warming. The sources of riverine Hg across the Mackenzie River basin (MRB) are uncertain, which leads to a poor understanding of potential future release. Measurements of dissolved and particulate mercury (DHg, PHg) and carbon (DOC, POC) concentration were performed, along with analyses of Hg stable isotope ratios (incl. ∆199Hg, δ202Hg), radiocarbon content (∆14C) and optical properties of DOC of river water. Isotopic ratios of Hg revealed a closer association to terrestrial Hg reservoirs for the particulate fraction, while the dissolved fraction was more closely associated with atmospheric deposition sources of shorter turnover time. There was a positive correlation between the ∆14C-OC and riverine Hg concentration for both particulate and dissolved fractions, indicating that waters transporting older-OC (14C-depleted) also contained higher levels of Hg. In the dissolved fraction, older DOC was also associated with higher molecular weight, aromaticity and humic content, which are likely associated with higher Hg-binding potential. Riverine PHg concentration increased with turbidity and SO4 concentration. There were large contrasts in Hg concentration and OC age and quality among the mountain and lowland sectors of the MRB, which likely reflect the spatial distribution of various terrestrial Hg and OC reservoirs, including weathering of sulfate minerals, erosion and extraction of coal deposits, thawing permafrost, forest fires, peatlands, and forests. Results revealed major differences in the sources of particulate and dissolved riverine Hg, but nonetheless a common positive association with older riverine OC. These findings reveal that a complex mixture of Hg sources, supplied across the MRB, will contribute to future trends in Hg export to the Arctic Ocean under rapid environmental changes.

Peat stored in large wetlands plays an important role in the carbon cycle and strongly influences water quality of terrestrial surface water bodies. At the same time, peat is also stored in the direct vicinity of many boreal forest streams. From this strategic position, peat can receive and chemically reset hillslope water before it reaches the stream network. Yet, in contrast to large wetlands, only little spatial information is available on the lateral extent of near-stream peat and even less about its vertical variation. Here, we present field data on peat depth and lateral extent collected from approximately 200 transects (with 12 soil profiles taken per transect) distributed across the entire stream network of the Krycklan boreal catchment in Northern Sweden. This soil profile data revealed a considerable heterogeneity of peat and organic horizon thicknesses. By combining the field data with morphological and geological maps, we show how parent material, stream order and local topography influence near stream peat structures. Furthermore, we discuss potential consequences on surface water quality by linking the detailed peat data set to estimates of lateral, shallow groundwater inflows derived from hydrometric measurements and digital terrain analysis.

The occurrence and distribution of 111 organic micropollutants (OMPs) were evaluated in water and sediment samples from Lake Malaren, Sweden, using a liquid chromatography-tandem mass spectrometry method. The partitioning of contaminants between lake compartments was estimated using solid water distribution coefficients (K-d) and organic carbon-water partitioning coefficients (K-OC). In total, 30 and 24 OMPs were detected in lake water and sediment, respectively. Concentrations ranged from low ng/L to 89 ng/L (lamotrigine) in lake water and from low ng/g dry weight (dw) to 28 ng/g dw (citalopram) in sediment. Carbamazepine, lamotrigine, caffeine, and tolyltriazole were the dominant compounds in Lake Malaren samples (both water and sediment). Seventeen OMPs were detected in both water and sediment samples, including carbamazepine, DEET, tolyltriazole, bicalutamide, caffeine, lamotrigine, and cetirizine. Log K-d values varied between 0.84 for lamotrigine and 4.4 for citalopram, while log K-OC values varied between 2.1 for lamotrigine and 5.9 for citalopram. These results indicate that sorption to sediment plays a minor role in removal of all OMPs analyzed in the aqueous phase except for citalopram and cetirizine, which showed high sorption potential. The environmental risks of OMPs were assessed based on the RQ values. The worst-case scenario for environmental risk assessment was conducted using the maximum measured environment concentration. For most of the target OMPs, including tolyltriazole, bicalutamide, fexofenadine, oxazepam, cetirizine, and diclofenac, the RQ values were below 0.01, indicating low or no risk to lake ecosystems. (C) 2020 Elsevier Ltd. All rights reserved.

Per- and polyfluoroalkyl substances (PFASs) have been ubiquitously detected in drinking water which poses a risk for human exposure. In this study, the treatment efficiency for the removal of 15 PFASs was examined in a full-scale drinking water treatment plant (DWTP) in the City of Uppsala, Sweden, over a period of two years (2015–2017). Removal of the five frequently detected PFASs was influenced by the total operation time of granular activated carbon (GAC) filters, GAC type and surface loading rate. The average removal efficiency of PFASs ranged from 92 to 100% for “young” GAC filters and decreased to 7.0–100% for “old” GAC filters (up to 357 operation days, 29 300 bed volumes (BV) treated). Flow-rates were adjusted in two full-scale GAC filters of different operational age to examine the removal of PFAS and organic matter depending on GAC operational age and operating flow. The decrease in flow-rate by 10 L s−1 from 39 to 29 L s−1 led to an average increase of 14% and 6.5% in total PFAS removal efficiency for an “old” (264 operation days, 21 971 BV treated) and a “young” GAC filter (63 operation days, 5 725 BV treated), respectively. A cost-analysis for various operation scenarios illustrated the dominating effect of treatment goals and costs for GAC regeneration on overall GAC operation costs. The unit costs for GAC filters ranged from 0.08 to 0.10 € m−3 water treated and 0.020-0.025 € m−3 water treated for a treatment goal of 10 ng L−1 and 85 ng L−1, respectively, for ∑ 11 PFAS. Furthermore, it was concluded that prolonging the GAC service life by lowering the flow-rates after reaching the treatment goal could lead to a 26% cost-deduction. The results and methods presented in this study give drinking water providers valuable tools for the operation of a full-scale treatment train for the removal of PFAS in contaminated raw water.

Deteriorated concrete and interstitial solutions (IS) were collected from Austrian tunnels to elucidate potential connections between de-dolomitization caused by coupled alkali carbonate reactions (ACR) and thaumasite form of sulfate attack (TSA). A conceptual reaction model for the portlandite–CSH phases–dolomite–calcium sulfate–calcite–brucite–thaumasite system was developed based on experimental data, hydrochemical modelling, IS chemistry and apparent concrete compositions. During the initial stage of sulfate attack, ettringite and gypsum formation weakened the concrete's microstructure and initiated ACR. Leaching of hydrated cement phases resulted in IS with a pH ~ 12-13, which promoted incongruent dolomite dissolution. Infiltration of Ca–SO4–type ground water into the de-dolomitization zone facilitated calcite and brucite neo-formations at 13 > pH > 10.5 during advanced states of concrete deterioration and subsequently resulted in thaumasite precipitation at pH ~ 8.7. In this contribution, the reaction mechanisms and environmental controls of de-dolomitization are discussed in relation to the durability of concrete under sulfate attack.

The boreal ecoregion supports about one-third of the world's forest. Over 90% of boreal forest streams are found in headwaters, where terrestrial-aquatic interfaces are dominated by organic matter (OM)-rich riparian zones (RZs). Because these transition zones are key features controlling catchment biogeochemistry, appropriate RZ conceptualizations are needed to sustainably manage surface water quality in the face of a changing climate and increased demands for forest biomass. Here we present a simple, yet comprehensive, conceptualization of RZ function based on hydrological connectivity, biogeochemical processes, and spatial heterogeneity. We consider four dimensions of hydrological connectivity: (1) laterally along hillslopes, (2) longitudinally along the stream, (3) vertically down the riparian profile, and (4) temporally through event-based and seasonal changes in hydrology. Of particular importance is the vertical dimension, characterized by a 'Dominant Source Layer' that has the highest contribution to solute and water fluxes to streams. In addition to serving as the primary source of OM to boreal streams, RZs shape water chemistry through two sets of OM-dependent biogeochemical processes: (1) transport and retention of OM-associated material and (2) redox-mediated transformations controlled by RZ water residence time and availability of labile OM. These processes can lead to both retention and release of pollutants. Variations in width, hydrological connectivity, and OM storage drive spatial heterogeneity in RZ biogeochemical function. This conceptualization provides a useful theoretical framework for environmental scientists and ecologically sustainable and economically effective forest management in the boreal region and elsewhere, where forest headwaters are dominated by low-gradient, OM-rich RZs.

Cation release rates to catchment runoff from chemical weathering were assessed using an integrated catchment model that included the soil's unsaturated, saturated and riparian zones. In-situ mineral dissolution rates were calculated in these zones as a function of pH, aluminum and dissolved organic carbon (DOC) concentrations along a hillslope in Northern Sweden where soil water was monitored over nine years. Three independent sets of mineral dissolution equations of varying complexity were used: PROFILE, Transition-State Theory (TST), and the Palandri & Kharaka database. Normalization of the rate-coefficients was necessary to compare the equations, as published rate-coefficients gave base cation release rates differing by several orders of magnitude. After normalizing the TST- and Palandri & Kharaka-rate coefficients to match the base cation release rates calculated from the PROFILE-equations, calculated Ca2 + and Mg2 + release rates are consistent with mass balance calculations, whereas those of Na+ and K+ are overestimated. Our calculations further indicate that a significant proportion of base cations are released from the organic soils in the near-stream zone, in part due to its finer texture. Of the three sets of rate equations, the base cation release rates calculated from the normalized TST-equations were more variable than those calculated using the other two sets of equations, both spatially and temporally, due to its higher sensitivity to pH. In contrast, the normalized Palandri & Kharaka-equations were more sensitive to variations in soil temperature.

The study evaluates the biogeochemical model ForSAFE-2D, designed to simulate water and chemical transport from the forest to the stream, by simulating the hydrology and the transport of the chemical tracer chloride (Cl−) along a forest hillslope in Northern Sweden. The simulated Cl− exports were in balance with the simulated inputs but measurements suggested a net release of Cl− from the catchment. Underestimated deposition inputs (deposition peaks and possibly dry deposition) were probably and partially responsible for this mismatch. However, we could not exclude that other soil biogeochemical processes omitted in ForSAFE-2D could also contribute to Cl− exports from the catchment. The study showed that ForSAFE-2D is a promising tool to better understand the factors that regulate the chemical export from the forest to the stream. The results also confirmed that there are limitations in using Cl− as a tracer in forest ecosystems.

Symbiotic ectomycorrhizal fungi mobilise nutrients from both organic and inorganic substrates and supply them to their host plants. Their role in mobilising base cations and phosphorus from mineral substrates through weathering has received increasing attention in recent years but the processes involved remain to be elucidated. We grew selected ectomycorrhizal and nonmycorrhizal fungi in axenic systems containing mineral and organic substrates and examined their capacity to fractionate and assimilate stable isotopes of magnesium. The mycorrhizal fungi were significantly depleted in heavy isotopes with the lowest Δ26Mg values (the difference between δ26Mg in fungal tissue and δ26Mg in the substrate) compared with nonmycorrhizal fungi, when grown on mineral substrates containing granite particles. The ectomycorrhizal fungi accumulated significantly higher concentrations of Mg, K and P than the nonmycorrhizal fungi. There was a highly significant statistical relationship between δ26Mg tissue signature and mycelial concentration of Mg, with a clear separation between most ectomycorrhizal fungi and the nonmycorrhizal fungi. These results are consistent with the idea that ectomycorrhizal fungi have evolved efficient mechanisms to mobilise, transport and store Mg within their mycelia. This article is protected by copyright. All rights reserved.

Per- and polyfluoralkyl substances (PFASs) are a major concern in pollution of drinking water sources and aquatic environments. This study investigated the sorption behavior of 17 PFASs of varying chain lengths and functional groups to 44 conventional and novel inorganic and organic sorbents with potential in treatment of PFAS-contaminated water or soil. For the first time, a large number of sorbents were tested for a wide variety of PFASs in batch sorption experiments under controlled experimental set-up. Also, the sorption behavior of four different dyes (methylene blue, crystal violet, indigo carmine, rose bengal) was also determined, to assess whether dyes can be used as a proxy for PFAS sorption. Of the 44 sorbents tested, PFASs sorbed best (mean >99.9 %) to activated carbons (granulated and pulverized (n = 5)). Sorption of PFASs to magnesium chloride-fortified biochar, Moringa seed, and pyrolytic carbon waste was 17- to 25-fold higher than to sand. Sorption generally increased with increasing perfluorocarbon chain length and based as follows on functional group: fluorotelomer sulfonic acids (FTSAs)

The main objective of this study was to comprehensively investigate the occurrence of organic micropollutants (OMPs) in the surface water in Lake Malaren over a period of one year and assess the spatial (horizontal and vertical) distribution and seasonal trends of OMPs. The applied multi-residue method comprised 111 OMPs covering compounds with wide range of physicalal–chemical properties. In total, 46 OMPs were detected at least once above limit of quantification (LOQ). DEET (diethyltoluamide), lamotrigine, bicalutamide, tolyltriazole, caffeine, carbamazepine, metoprolol, oxazepam, cetirizine, fexofenadine, lidocaine and tramadol were detected in more than 75% of the sampling points. The highest detected concentration was found for lamotrigine with 140 ng/L. The locations Ekoln and Vasterasfjarden were identified to be most affected by OMPs pollution. In the surface water (0.5 m depth) most highest concentrations of OMPs were observed in spring and lower concentrations in summer. Antihistamine demonstrated a seasonal trend that can be related to seasonal consumption patterns. The investigation of the vertical distribution of OMPs demonstrated that thermal lake stratification can lead to different concentrations within the water column. For instance, in February the highest concentration for most OMPs was observed in the deepest sampled water depth (30 m). Two industrial chemicals, tolyltriazole and tris(2-butoxylethyl)phosphate were detected frequently and it is recommended to incorporate these compounds more regularly in future analysis. To the best of our knowledge, this study is the first one to report the occurrence and distribution of OMPs representing such wide physico-chemical properties, including industrial chemicals, in a Swedish lake.

Using a 15 year stream record from a northern boreal catchment, we demonstrate that the inter-annual variation in dissolved organic carbon (DOC) concentrations during snowmelt was related to discharge, winter climate and previous DOC export. A short and intense snowmelt gave higher stream water DOC concentrations, as did long winters, while a high previous DOC export during the antecedent summer and autumn resulted in lower concentrations during the following spring. By removing the effect of discharge we could detect that the length of winter affected the modeled soil water DOC concentrations during the following snowmelt period, which in turn affected the concentrations in the stream. Winter climate explained more of the stream water DOC variations than previous DOC export during the antecedent summer and autumn.

Photochemical and microbial processing of dissolved organic matter in streams and soilwater

Management actions often need to be taken in the absence of ecological information to mitigate the impact of pressing environmental problems. Managers counteracted the detrimental effects of cultural acidification on aquatic ecosystems during the industrial era using liming to salvage biodiversity and ecosystem services. However, historical contingencies, i.e., whether lakes were naturally acidic or degraded because of acidification, were largely unknown and therefore not accounted for in management. It is uncertain whether liming outcomes had a potentially detrimental effect on naturally acidic lakes. Evidence from paleolimnological reconstructions allowed us to analyze community structure in limed acidified and naturally acidic lakes, and acidified and circumneutral references. We analyzed community structure of phytoplankton, zooplankton, macroinvertebrates (littoral, sublittoral, profundal), and fish between 2000 and 2004. Naturally acidic limed lakes formed communities that were not representative of the other lake types. The occurrence of fish species relevant for ecosystem service provisioning (fisheries potential) in naturally acidic limed lakes were confounded by biogeographical factors. In addition, sustained changes in water quality were conducive to harmful algal blooms. This highlights a pathological outcome of liming lakes when their naturally acidic conditions are not accounted for. Because liming is an important social-ecological system, sustained ecological change of lakes might incur undesired costs for societies in the long term.

Patient satisfaction with psychiatric treatment has emerged as an important factor with respect to the quality of health care.Patient satisfaction using the Zurich Satisfaction Questionnaire (ZUF-8) as well as symptom severity (measured with the Hamilton Depression Scale [HRSD], Brief Psychiatric Rating Scale and Clinical Global Impression Scale) was assessed at admission and discharge of inpatient treatment in patients with a major depressive episode (MDD, N = 217) and schizophrenia (N = 75). Differences between the two diagnostic groups (using T-tests) and correlations of patient satisfaction with different social and treatment variables were calculated (Pearson product-moment correlation).The mean score of patient satisfaction was 26.8 points (ZUF-8; range 8-32 points), without differences between MDD and schizophrenia (t = 0.45, p = 0.78). Patients with MDD and personality disorder showed lower satisfaction than patients with MDD without personality disorder (t = 2.31, p = 0.03). Patient satisfaction correlated negatively with severity of depressive symptoms at discharge (HRSD: r = - 0.38; p0.01) and number of comorbidities (r = - 0.42; p0.01) in MDD. Number of prescribed drugs correlated negatively with patient satisfaction in both groups (depression: r = - 0.28, p = 0.02; schizophrenia: r = - 0.24; p = 0.03).Patient satisfaction was high without differences between MDD and schizophrenia. Severity of disease and comorbidites in MDD and number of prescribed drugs in both groups were related with reduced patient satisfaction.

Drinking water treatment plants (DWTPs) are constantly adapting to a host of emerging threats including the removal of micro-pollutants like perfluoroalkyl substances (PFASs), while concurrently considering how background levels of dissolved organic matter (DOM) influences their removal efficiency. Two adsorbents, namely anion exchange (AE) and granulated active carbon (GAC) have shown particular promise for PFAS removal, yet the influence of background levels of DOM remains poorly explored. Here we considered how the removal efficiency of 13 PFASs are influenced by two contrasting types of DOM at four concentrations, using both AE (Purolite A-600®) and GAC (Filtrasorb 400®). We placed emphasis on the pre-equilibrium conditions to gain better mechanistic insight into the dynamics between DOM, PFASs and adsorbents. We found AE to be very effective at removing both PFASs and DOM, while largely remaining resistant to even high levels of background DOM (8 mg carbon L−1) and surprisingly found that smaller PFASs were removed slightly more efficiently than longer chained counterparts, In contrast, PFAS removal efficiency with GAC was highly variable with PFAS chain length, often improving in the presence of DOM, but with variable response based on the type of DOM and PFAS chain length.

Forest biofuel is a main provider of energy in Sweden and the market is expected to grow even further in the future. Removal of logging residues via harvest can lead to short-term acidification but the long-term effects are largely unknown. The objectives of this study were to 1) model the long-term effect of whole-tree harvest (WTH) on soil and stream water acidity and 2) perform sensitivity analyses by varying the amounts of logging residues, calcium (Ca 2 + ) concentrations in tree biomass and site productivity in nine alternate scenarios. Data from three Swedish forested catchments and the Model of Acidification of Groundwater in Catchments (MAGIC) were used to simulate changes in forest soil exchangeable Ca 2 + pools and stream water acid neutralizing capacity (ANC) at Gammtratten, Kindla and Aneboda. Large depletions in soil Ca 2 + supply and a reversal of the positive trend in stream ANC were predicted for all three sites after WTH. However, the magnitude of impact on stream ANC varied depending on site and the concentration of mobile strong acid anions. Contrary to common beliefs, the largest decrease in modelled ANC was observed at the well-buffered site Gammtratten. The effects at Kindla and Aneboda were much more limited and not large enough to offset the general recovery from acidification. Varying the tree biomass Ca 2 + concentrations exerted the largest impact on modelled outcome. Site productivity was the second most important variable whereas changing biomass amounts left on site only marginally affected the results. The outcome from the sensitivity analyses pointed in the same direction of change as in the base scenario, except for Kindla where soil Ca 2 + pools were predicted to be replenished under a given set of input data. The reliability of modelled outcome would increase by using site-specific Ca 2 + concentrations in tree biomass and field determined identification of site productivity.

Health-related quality of life (HRQoL) is important for long-term social functioning. It is considerably reduced in patients with depression. We studied the impact of HRQoL on treatment outcome in patients with unipolar depression. Furthermore, we analysed factors associated with HRQoL in inpatients with unipolar depression. One hundred and eighty patients suffering from major depressive disorder were evaluated during their inpatient treatment by assessing admission and discharge depression severity and their HRQoL, using the Medical Outcomes Study 12-item Short Form (SF-12). Baseline and treatment variables associated with HRQoL were examined by regression analysis. Primary outcome measures were the Hamilton Rating Scale and the Beck Depression Inventory. HRQoL improved significantly during inpatient treatment. Lower HRQoL outcomes were strongly associated with higher age, somatic comorbidities, a recurrent depressive disorder and stronger depressive symptoms at admission. Additionally, patients with a complex treatment situation (high number of medications, antidepressant switch) showed stronger impairment of HRQoL. Personality disorders and additional psychotherapy did not predict HRQoL. The inpatient treatment resulted in an increase of the SF-12 scores, although to a lower extent than depressive symptoms. Several factors negatively influence HRQoL, such as the presence of somatic and axis I psychiatric comorbiditites and a recurrent or severe depressive episode. Targeting somatic comorbidities in patients with unipolar depression seem to play an important role for HRQoL.

The boreal forest carbon balance is predicted to be particularly sensitive to climate change. Carbon balance estimates of these biomes stem mainly from eddy-covariance measurements of net ecosystem exchange (NEE). However, a full net ecosystem carbon balance (NECB) must include the lateral carbon export (LCE) through discharge. We show that annual LCE at a boreal forest site ranged from 4 to 28%, averaging 11% (standard deviation of 8%), of annual NEE over 13 years. Annual LCE and NEE are strongly anticorrelated; years with weak NEE coincide with high LCE. The decreased NEE in response to increased precipitation is caused by a reduction in the amount of incoming radiation caused by clouds. If our finding is also valid for other sites, it implies that increased precipitation at high latitudes may shift forest NECB in large areas of the boreal biome. Our results call for future analysis of this dual effect of precipitation on NEE and LCE.

Saharan paleo-groundwater from the Hasouna area of Libya contains up to 1.8 mM of nitrate, which exceeds the World Health Organization limit for drinking water, but the origin is still disputed. Herein we show that a positive 17O excess in NO3− (Δ17ONO3 = Δ17ONO3 − 0.52 δ18ONO3) is preserved in the paleo-groundwater. The 17O excess provides an excellent tracer of atmospheric NO3−, which is caused by the interaction of ozone with NOx via photochemical reactions, coupled with a non-mass-dependent isotope fractionation. Our Δ17ONO3 data from 0.4 to 5.0 ‰ (n = 28) indicate that up to 20 mol % of total dissolved NO3- originated from the Earth's atmosphere (x[NO3−]atm), where the remaining NO3− refers to microbially induced nitrification in soils. High Δ17ONO3 values correspond to soils that are barren in dry periods, while low Δ17ONO3 values correspond to more fertile soils. Coupled high Δ17ONO3 and high x[NO3−]atm values are caused by a sudden wash-out of accumulated disposition of atmospheric NO3− on plants, soil surfaces and in vadose zones within humid–wet cycles. The individual isotope and chemical composition of the Hasouna groundwater can be followed by a binary mixing approach using the lowest and highest mineralised groundwater as end members without considering evaporation. Using the δ34SSO4 and δ18OSO4 isotope signature of dissolved SO42−, no indication is found for a superimposition by denitrification, e.g. involving pyrite minerals within the aquifers. It is suggested that dissolved SO42− originates from the dissolution of CaSO4 minerals during groundwater evolution.

In this study we present data from a seven-year time series from 15 nested streams within a 68 km(2) catchment, covering a pH gradient of almost three units. We demonstrate that the two landscape t ...

The riparian zone is the narrow strip of land, which lines lakes and watercourses. In the boreal region the riparian zone of headwaters often tends to be -wetland-like with high concentrations of organic matter, low pH and more or less reducing conditions. This means that riparian soils in many respects are different from the podzols and other types of mineral soils that dominate the boreal landscape. In this study a large number of major and trace elements (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Si, Sr, Th, Ti, U, V, Zn, Zr) and other parameters such as sulphate, total organic carbon (TOC) and pH were analysed in groundwater and soil water in a boreal hillslope. The objective was to investigate how the chemistry changes as the groundwater passes through the riparian zone and enters the stream. Most of the investigated elements displayed substantially higher (up to 60 times) concentrations in the riparian soils than in the uphill mineral soils. There were also examples of nearly uniform concentrations throughout the transect (e.g. Na and Si), but in only a few cases were lower concentrations observed in the riparian zone (e.g. K, Mg and Ca). The degree of enrichment in the riparian soils could be linked to the affinity for organic matter, indicating that the pattern with strongly elevated concentrations in riparian soils is typical for organophilic elements. However, the elevated concentrations of many elements in the riparian zone could not be linked to increased uptake in biota (bilberry leaves and spruce shoots). In summary, the results confirmed that the riparian zone plays a central role for regulating the stream water quality and the transfer of a wide range of elements from terrestrial to aquatic ecosystems. Hence, riparian soils are essential for understanding the fate of nutrients, pollutants and other substances in the boreal landscape.

Despite the high clinical and epidemiological relevance of persistent depression, little is known about its specific psychopathology and whether it is distinct from recurrent depression. Depression in general has been associated with blunted affective reactivity but the evidence from previous studies is inconsistent. Here, we asked whether affective reactivity might differ between persistent and recurrent depression.Twenty patients with persistent depression, 20 patients with recurrent depression and 20 healthy controls (HC) were recruited. Both patient groups showed moderate symptom severity. All participants underwent a sad mood induction procedure. Affective reactivity was assessed with the Positive and Negative Affect Schedule (PANAS) before and after mood induction.We found a striking difference in affective reactivity between patient groups. While the persistent group showed blunted reactivity to mood induction, the recurrent group demonstrated an affective response that was comparable to HC, with an increase in negative and a decrease in positive affect. Blunted affective reactivity was thus specifically associated with persistent in contrast to recurrent depression.These results highlight affective reactivity as an important psychopathological feature that differs between the two patient groups. Preserved affective reactivity to emotional stimuli in the recurrent group might reflect a resilience factor against persistence of depression.

This study examines the relationship of personality disorders (PDs) with the outcome of an inpatient treatment for depression. One hundred sixty-eight inpatients with unipolar depression (41% with PD according to SCID-II) were assessed at admission, discharge, and 1-year follow-up. Patients without as well as with PD showed a significant and comparable intake-to-discharge symptom reduction in all inventories. At posttreatment, patients with PD scored higher in self-report measures of symptom severity (Brief Symptom Inventory, Beck Depression Inventory) than patients without PD, due to their higher symptom levels at intake. However, there was no difference in clinician-rated therapy outcome (Hamilton Rating Scale for Depression [17-item version], Global Assessment of Functioning Scale, Clinical Global Impression Scale) between both patient groups at discharge. At 1-year follow-up, patients without PD maintained their treatment outcome, whereas patients with PD showed a slight increase in symptom severity, compared to discharge. The results suggest that a difference in acute treatment outcome between depressed patients with and without PD may be found using self-ratings but not expert ratings of symptom severity. Furthermore, the importance of subsequent outpatient treatment that takes into account the special needs of depressed patients with comorbid PD is highlighted.

Riparian zones (RZ) are a major factor controlling water chemistry in forest streams. Base cations' (BC) concentrations, fluxes, and cycling in the RZ merit attention because a changing climate and increased forest harvesting could have negative consequences, including re-acidification, for boreal surface waters. We present a two-year study of BC and silica (Si) flow-weighted concentrations from 13 RZ and 14 streams in different landscape elements of a boreal catchment in northern Sweden. The spatial variation in BC and Si dynamics in both RZ and streams was explained by differences in landscape element type, with highest concentrations in silty sediments and lowest concentrations in peat-dominated wetland areas. Temporal stability in BC and Si concentrations in riparian soil water, remarkably stable Mg/Ca ratios, and homogeneous mineralogy suggest that patterns found in the RZ are a result of a distinct mineralogical upslope signal in groundwater. Stream water Mg/Ca ratios indicate that the signal is subsequently maintained in the streams. Flow-weighted concentrations of Ca, Mg, and Na in headwater streams were represented by the corresponding concentrations in the RZ, which were estimated using the Riparian Flow-Concentration Integration Model (RIM) approach. Stream and RZ flow-weighted concentrations differed for K and Si, suggesting a stronger biogeochemical influence on these elements, including K recirculation by vegetation and retention of Si within the RZ. Potential increases in groundwater levels linked to forest harvesting or changes in precipitation regimes would tend to reduce BC concentrations from RZ to streams, potentially leading to episodic acidification.

Riverine transport of iron (Fe) and arsenic (As) is affected by their associations with natural organic matter (NOM) and suspended iron (oxy)hydroxides. Speciation has a strong influence on element transport from the headwaters to the ocean because NOM may be transported over longer distances compared to iron (oxy)hydroxides. We show that Fe speciation changes along the flow path of a boreal watercourse, as water moves from NOM-rich, acidic first-order streams with pH as low as 3.9 to less acidic higher-order systems (up to pH 6.4). Analysis by Flow Field-Flow Fractionation and chemical equilibrium modeling revealed that Fe from wetland-dominated headwaters was mainly exported as Fe-NOM complexes; in catchments with a stream order1 and with higher pH, Fe was present in Fe-NOM complexes and precipitated as nanoparticulate iron(oxy)hydroxides which aggregated as the pH increased, with their size eventually exceeding the membrane filters cutoff (0.2 μm). The measured NOM-bound Fe decreased with increasing pH, from 0.38 to 0.16 mmol Fe·g(NOM)(-1). The high concentrations of NOM-bound Fe emphasize the importance of boreal catchments to Fe export to the oceans. Concentrations of As in the0.2 μm fraction but larger than what is usually considered "truly dissolved" (1000 g·mol(-1)), decreased from 75% to 26% with increasing pH. The As in this size range was mainly associated with NOM but at pH4.5 became associated with iron(oxy)hydroxides, and its transport thus became more coupled to that of the iron(oxy)hydroxides downstream in the circumneutral streams.

Natural organic matter (NOM) serve as precursors for disinfection byproducts (DBPs) in drinking water production making NOM removal essential in predisinfection treatment processes. We identified molecular formulas of chlorinated DBPs after chlorination and chloramination in four Swedish surface water treatment plants (WTPs) using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chlorine-containing formulas were detected before and after disinfection and were therefore classified to identify DBPs. In total, 499 DBPs were detected, of which 230 have not been reported earlier. The byproducts had, as a group, significantly lower ratio of hydrogen to carbon (H/C) and significantly higher average carbon oxidation state (COS), double bond equivalents per carbon (DBE/C) and ratio of oxygen to carbon (O/C) compared to Cl-containing components present before disinfection and CHO formulas in samples taken both before and after disinfection. Electrophilic substitution, the proposed most significant reaction pathway for chlorination of NOM, results in carbon oxidation and decreased H/C while O/C and DBE/C is left unchanged. Because the identified DBPs had significantly higher DBE/C and O/C than the CHO formulas we concluded that chlorination of NOM during disinfection is selective toward components with relatively high double bond equivalency and number of oxygen atoms per carbon. Furthermore, choice of disinfectant, dose, and predisinfection treatment at the different WTPs resulted in distinct patterns in the occurrence of DBP formulas.

The formation of anhydrous CaCO 3 polymorphs is very common and widespread in low-temperature inorganic and biogenic environments. An increase in aqueous carbonate concentration frequently induces CaCO 3 formation in nature. Nevertheless, no systematic experiment has assessed the impact of the continuous accumulation of aqueous carbonate ions on CaCO 3 formation. Also, the coupled influences of temperature, inorganic and organic additives, and rates of aqueous carbonate accumulation and supersaturation to induce CaCO 3 polymorph formation have been poorly investigated. The latter two factors comprise reaction times that are required for nucleation and subsequently affect the precipitation kinetics through ongoing CaCO 3 formation. To address these issues, CaCO 3 formation was experimentally studied at a variety of aqueous carbonate accumulation rates (10 − 1.5 ≤ ACAR ≤ 10 1.8 μmol h − 1 l − 1 ) between 6 and 40 °C using a CO 2 diffusion technique at conditions that were analogous to sea water (pH 8.3; [Ca 2 + ] = 10 mmol l − 1 ). The impacts of an inorganic and organic constituent on CaCO 3 formation were investigated using Mg 2 + and polyaspartic acid (Pasp) at concentrations up to 55 mmol l − 1 and 3.4 mg l − 1 , respectively. The experimental data clearly reveal that the time for CaCO 3 nucleation depends strongly on ACAR, T, [Mg 2 + ] (> 0.5 mmol l − 1 ), and [Pasp] (> 0.1 mg l − 1 ) but not on the formation of different CaCO 3 polymorphs. Elevated ACAR results in earlier CaCO 3 formation and causes Mg 2 + to have less of an impact on the retardation of nucleation. The ion activity product (IAP) required for CaCO 3 nucleation is positively correlated to the subsequent CaCO 3 precipitation rates but is independent of whether aragonite or calcite formation is induced. The type of CaCO 3 polymorph from the primary nuclei is controlled by the influences of Mg 2 + and Pasp, which are coupled to ACAR and T. Elevated ACAR, T, and [Mg 2 + ] promote the formation of aragonite, and high [Mg 2 + ] levels suppress the formation of vaterite. In contrast, [Pasp] > 0.02 mg l − 1 inhibits aragonite and favours vaterite formation. Thus, if both Mg 2 + and Pasp are present, the formation of calcite is favoured. The precipitation rates for ongoing calcite and aragonite formation are nearly the same at analogous conditions and particularly for a given IAP. According to our experimental results, the combined impacts of ACAR, T, [Mg 2 + ], and [Pasp] must be considered to identify distinct conditions of CaCO 3 polymorph formation and precipitation kinetics.

Long-term data series (1996–2009) for eleven acidic headwater streams (< 10 km2) in Sweden were analyzed to determine factors controlling concentrations of trace metals. In-stream chemical data as well climatic, flow, and deposition chemistry data were used to develop models predicting concentrations of chromium (Cr), lead (Pb), and zinc (Zn). Data were initially analyzed using partial least squares to determine a set of variables that could predict metal concentrations across all sites. Organic matter (as absorbance) and iron related positively to Pb and Cr, while pH related negatively to Pb and Zn. Other variables such as conductivity, manganese, and temperature were important as well. Multiple linear regression was then used to determine minimally adequate prediction models which explained an average of 35% (Cr), 52% (Zn), and 72% (Pb) of metal variation across all sites. While models explained at least 50% of variation in the majority of sites for Pb (10) and Zn (8), only three sites met this criterion for Cr. Investigation of variation between site models for each metal revealed geographical (altitude), chemical (sulfate), and land-use (silvaculture) influences on predictive power of the models. Residual analysis revealed seasonal differences in the ability of the models to predict metal concentrations as well. Expected future changes in model variables were applied and results showed the potential for long-term increases (Pb) or decreases (Zn) for trace metal concentrations at these sites.

The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream comparable to measurements. The most relevant differences compared to streamflow measurements are that the model simulates a higher base flow in winter and lower flow peaks after snowmelt. These differences are mainly caused by the assumptions made to regulate the percolation at the bottom of the simulated soil columns. The capability for simulating lateral flows and a saturated zone in ForSAFE can greatly improve the simulation of chemical exchange in the soil and export of elements from the soil to watercourses. Such a model can help improve the understanding of how environmental changes in the forest landscape will influence chemical loads to surface waters.

Rising organic matter concentrations in surface waters in many Nordic countries require current drinking water treatment processes to be adapted. Accordingly, the use of a novel nanofiltration (NF) membrane was studied during a nine month period in pilot scale at a large drinking water treatment plant in Stockholm, Sweden. A chemically resistant hollow-fibre NF membrane was fed with full scale process water from a rapid sand filter after aluminum sulfate coagulation. The combined coagulation and NF process removed more than 90% of the incoming lake water dissolved organic carbon (DOC) (8.7mgCL(-1)), and 96% of the absorbance at 254nm (A254) (0.28cm(-1) incoming absorbance). Including granulated active carbon GAC) filter, the complete pilot plant treatment process we observed decreases in DOC concentration (8.7-0.5mgCL(-1)), SUVA (3.1-1.7mg(-1)Lm(-1)), and the average nominal molecular mass (670-440Da). Meanwhile, water hardness was practically unaffected (

Surface waters are the main source of drinking water in many regions. Increasing organic carbon concentrations are a cause for concern in Nordic countries since both dissolved and particulate organic carbon can transport contaminants and adversely affect drinking water treatment processes. We present a long-term study of dynamics of total (particulate and dissolved) organic carbon (TOC) concentrations in the River Fyris. This river supplies drinking water to approximately 200000 people in Uppsala, Sweden. The River Fyris is a main tributary to Lake Malaren, which supplies drinking water to approximately 2 million people in the greater Stockholm area. Utilities responsible for drinking water supply in both Uppsala and Stockholm have expressed concerns about possible increases in TOC. We evaluate organic carbon dynamics within the Fyris catchment by calculating areal mass exports using observed TOC concentrations and modeled flows and by modeling dissolved organic carbon (as a proxy for TOC) using the dynamic, process based INCA-C model. Exports of TOC from the catchment ranged from 0.8 to 5.8 g m − 2 year − 1 in the period 1995–2010. The variation in annual exports was related to climatic variability which influenced seasonality and amount of runoff. Exports and discharge uncoupled at the end of 2008. A dramatic increase in TOC concentrations was observed in 2009, which gradually declined in 2010–2011. INCA-C successfully reproduced the intra- and inter-annual variation in concentrations during 1996–2008 and 2010–2011 but failed to capture the anomalous increase in 2009. We evaluated a number of hypotheses to explain the anomaly in 2009 TOC values, ultimately none proved satisfactory. We draw two main conclusions: there is at least one unknown or unmeasured process controlling or influencing surface water TOC and INCA-C can be used as part of the decision-making process for current and future use of rivers for drinking water supply.

Surface water concentrations of dissolved organic carbon ([DOC]) are changing throughout the northern hemisphere due to changes in climate, land use and acid deposition. However, the relative importance of these drivers is unclear. Here, we use the Integrated Catchments model for Carbon (INCA-C) to simulate long-term (1996-2008) streamwater [DOC] at the four Swedish integrated monitoring (IM) sites. These are unmanaged headwater catchments with old-growth forests and no major changes in land use. Daily, seasonal and long-term variations in streamwater [DOC] driven by runoff, seasonal temperature and atmospheric sulfate (SO₄(2-)) deposition were observed at all sites. Using INCA-C, it was possible to reproduce observed patterns of variability in streamwater [DOC] at the four IM sites. Runoff was found to be the main short-term control on [DOC]. Seasonal patterns in [DOC] were controlled primarily by soil temperature. Measured SO₄(2-) deposition explained some of the long-term [DOC] variability at all sites.

Concentrations of organic acids in freshwaters have increased significantly during recent decades across large parts of Europe and North America. Different theories of the causes (e.g., recovery from acidification, climate change, land use) have different implications for defining the preindustrial levels for dissolved organic carbon (DOC), which are crucial for assessing acidification and other aspects of water quality. We demonstrate this by classifying the acidification status of 66 lakes with long-term observations, representative of about 12,700 acid-sensitive lakes in nemoral and boreal Sweden. Of these lakes, 47% are classified as significantly acidified (Delta pH >= 0.4), assuming preindustrial DOC levels were equal to those observed in 1990. But if instead, the higher DOC levels observed in 2009 define preindustrial conditions, half as many lakes are acidified (24%). This emphasizes the need to establish reference levels for DOC and casts new light on the classic controversy about natural versus anthropogenic acidification.

Long term data series (1996 through 2009) for trace metals were analyzed from a large number of streams and rivers across Sweden varying in tributary watershed size from 0.05 to 48 193 km2. The final data set included 139 stream sites with data for arsenic (As), cobalt (Co), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and vanadium (V). Between 7 % and 46 % of the sites analyzed showed significant trends according to the seasonal Kendall test. However, in contrast to previous studies and depositional patterns, a substantial portion of the trends were positive, especially for V (100 %), As (95 %), and Pb (68 %). Other metals (Zn and Cr) generally decreased, were mixed (Ni and Zn), or had very few trends (Co) over the study period. Trends by region were also analyzed and some showed significant variation between the north and south of Sweden. Regional trends for both Cu and Pb were positive (60 % and 93 %, respectively) in the southern region but strongly negative (93 % and 75 %, respectively) in the northern region. Kendall's τ coefficients were used to determine dependence between metals and potential in-stream drivers including total organic carbon (TOC), iron (Fe), pH, and sulphate (SO42−). TOC and Fe correlated positively and strongly with As, V, Pb, and Co while pH and SO42− generally correlated weakly, or not at all with the metals studied.

We bring together three decades of research from a boreal catchment to facilitate an improved mechanistic understanding of surface water dissolved organic carbon (DOC) regulation across multiple scales. The Krycklan Catchment Study encompasses 15 monitored nested research catchments, ranging from 3 to 6900 ha in size, as well as a set of monitored transects of forested and wetland soils. We show that in small homogenous catchments, hydrological functioning provides a first order control on the temporal variability of stream water DOC. In larger, more heterogeneous catchments, stream water DOC dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. As a consequence, streams with heterogeneous catchments undergo a temporal switch in the DOC source. In a typical boreal catchment covered by 10-20% wetlands, DOC originates predominantly from wetland sources during low flow conditions. During high flow, the major source of DOC is from forested areas of the catchment. We demonstrate that by connecting knowledge about DOC sources in the landscape with detailed hydrological process understanding, an improved representation of stream water DOC regulation can be provided. The purpose of this study is to serve as a framework for appreciating the role of regulating mechanisms, connectivity and scaling for understanding the pattern and dynamics of surface water DOC across complex landscapes. The results from this study suggest that the sensitivity of stream water DOC in the boreal landscape ultimately depends on changes within individual landscape elements, the proportion and connectivity of these affected landscape elements, and how these changes are propagated downstream.

Are current estimates of silicate minerals weathering rates precise enough to predict whether nutrient pools will recover after forest harvesting? Answering this question seems crucial for sustaina ...

The fate of hydrophobic organic compounds (HOCs) in soils and waters in a northern boreal catchment was explored through the development of a chemical fate model in a well-characterised catchment system dominated by two land types: forest and mire. Input was based solely on atmospheric deposition, dominated by accumulation in the winter snowpack. Release from soils was governed by the HOC concentration in soil, the soil organic carbon fraction and soil-water DOC content. The modelled export of selected HOCs in surface waters ranged between 11 and 250 ng day(-1) during the snow covered period, compared to 200 and 9600 ng/d during snow-melt; highlighting the importance of the snow pack as a source of these chemicals. The predicted levels of HOCs in surface water were in reasonable agreement to a limited set of measured values, although the model tended to over predict concentrations of HOCs for the forested sub-catchment, by over an order of magnitude in the case of hexachlorobenzene and PCB 180. This possibly reflects both the heterogeneity of the forest soils and the complicated and changing hydrology experienced between the different seasons.

Stable oxygen isotopic fractionation during inorganic calcite precipitation was experimentally studied by spontaneous precipitation at various pH (8.3 R − 2 h − 1 ) and temperatures (5, 25, and 40 °C) using the CO 2 diffusion technique. The results show that the apparent stable oxygen isotopic fractionation factor between calcite and water ( α calcite–water ) is affected by temperature, the pH of the solution, and the precipitation rate of calcite. Isotopic equilibrium is not maintained during spontaneous precipitation from the solution. Under isotopic non-equilibrium conditions, at a constant temperature and precipitation rate, apparent 1000ln α calcite–water decreases with increasing pH of the solution. If the temperature and pH are held constant, apparent 1000ln α calcite–water values decrease with elevated precipitation rates of calcite. At pH = 8.3, oxygen isotopic fractionation between inorganically precipitated calcite and water as a function of the precipitation rate ( R ) can be described by the expressions 1000 ln α calcite – water = - 1.102 log R + 34.56 1000 ln α calcite – water = - 1.094 log R + 30.87 1000 ln α calcite – water = - 0.534 log R + 26.80 at 5, 25, and 40 °C, respectively. The impact of precipitation rate on 1000ln α calcite–water value in our experiments clearly indicates a kinetic effect on oxygen isotopic fractionation during calcite precipitation from aqueous solution, even if calcite precipitated slowly from aqueous solution at the given temperature range. Our results support Coplen's work [Coplen T. B. (2007) Calibration of the calcite–water oxygen isotope geothermometer at Devils Hole, Nevada, a natural laboratory. Geochim. Cosmochim. Acta 71, 3948–3957], which indicates that the equilibrium oxygen isotopic fractionation factor might be greater than the commonly accepted value.

This paper defines landscape-scale patterns in the character of natural organic matter (NOM) and tests for relationships to catchment soil, vegetation and topography. The drainage network of a boreal catchment, subcatchment size 0.12–78 km2, in Northern Sweden was sampled in August 2002 during a period of stable low water flow. The NOM was characterized with UV/Vis spectroscopy, fluorescence, XAD-8 fractionation (%humic substances), gel permeation chromatography (apparent molecular weight), and elemental composition (C:N). The largest spatial variation was found for C:N, absorbance ratio, and specific visible absorptivity. The lowest variation was in fluorescence index, %humic substances and molecular retention time. But the variation in total organic carbon (TOC), iron and aluminium concentration was more than twice that of C:N. Between headwater and downstream sites no significant changes were distinguished in the NOM character. At stream reaches, junctions and lakes little change (

The adverse impacts of the inorganic labile monomeric Al (Al-i) fraction on aquatic organisms have meant that Al (Al-tot) determination and even speciation has become a routine part of environmenta ...

Otavite, witherite, calcite, strontianite, hydrozincite and hydrocerussite nucleation was induced by CO 2 diffusion through a polyethylene membrane into a metal bearing solution. Nucleation and ongoing precipitation was followed at 25 ± 1 °C by the chemical evolution of the solution and the consumption of sodium hydroxide (pH-stat conditions). X-ray diffraction patterns as well as FT-infrared and Raman spectra confirmed the formation of well crystallized solids, except for less crystalline hydrozincite. In several experiments simonkolleite and laurionite precipitated concurrently with hydrozincite and hydrocerussite. The carbonate end-member minerals, smithsonite and cerussite, however were not formed. Carbonate minerals crystallized as spherical aggregates of thin layered otavite, spherical orientated witherite needles, rhombohedral calcite, pseudo-hexagonal strontianite laths, fibrous lumps of hydrozincite and planar hexagonal hydrocerussite crystals. Crystal and aggregate sizes range between 1 and 100 μm. Nucleation occurred at well defined reaction times and distinct critical supersaturation indices (SI crit ). The time for nucleation at constant pH decreased as the initial metal concentration increased for a given solid. The SI crit values decreased in the order of hydrocerussite (3.2), otavite (2.5), strontianite (1.6), witherite (0.9) and calcite (0.7).

Summary Two different but complementary modelling approaches for reproducing the observed dynamics of total organic carbon (TOC) in a boreal stream are presented. One is based on a regression analysis, while the other is based on riparian soil conditions using a convolution of flow and concentration. Both approaches are relatively simple to establish and help to identify gaps in the process understanding of the TOC transport from soils to catchments runoff. The largest part of the temporal variation of stream TOC concentrations (4–46 mg L−1) in a forested headwater stream in the boreal zone in northern Sweden may be described using a four-parameter regression equation that has runoff and transformed air temperature as sole input variables. Runoff is assumed to be a proxy for soil wetness conditions and changing flow pathways which in turn caused most of the stream TOC variation. Temperature explained a significant part of the observed inter-annual variability. Long-term riparian hydrochemistry in soil solutions within 4 m of the stream also captures a surprisingly large part of the observed variation of stream TOC and highlights the importance of riparian soils. The riparian zone was used to reproduce stream TOC with the help of a convolution model based on flow and average riparian chemistry as input variables. There is a significant effect of wetting of the riparian soil that translates into a memory effect for subsequent episodes and thus contributes to controlling stream TOC concentrations. Situations with high flow introduce a large amount of variability into stream water TOC that may be related to memory effects, rapid groundwater fluctuations and other processes not identified so far. Two different climate scenarios for the region based on the IPCC scenarios were applied to the regression equation to test what effect the expected increase in precipitation and temperature and resulting changes in runoff would have on stream TOC concentrations assuming that the soil conditions remain unchanged. Both scenarios resulted in a mean increase of stream TOC concentrations of between 1.5 and 2.5 mg L−1 during the snow free season, which amounts to approximately 15% more TOC export compared to present conditions. Wetter and warmer conditions in the late autumn led to a difference of monthly average TOC of up to 5 mg L−1, suggesting that stream TOC may be particularly susceptible to climate variability during this season.