- 90615415
Rolf D Vogt
NIVA, Catchment processes, Department Member
We present long‐term changes in Norwegian lake water quality across regional gradients in atmospheric pollution, air temperature, hydrology, and vegetation using (a) a national representative lake survey carried out in 1995 and 2019... more
We present long‐term changes in Norwegian lake water quality across regional gradients in atmospheric pollution, air temperature, hydrology, and vegetation using (a) a national representative lake survey carried out in 1995 and 2019 (ThousandLakes), and (b) an annual lake survey from acid‐sensitive catchments (78 lakes, TrendLakes) from 1990 to 2020. Our analysis encompasses all major chemical constituents, for example, anions and cations, dissolved organic matter (DOM), nutrients, iron (Fe), and silicate (SiO2). During these decades, environmental changes included declines in sulfur (S) and nitrogen (N) deposition, climate warming, and increase in forest biomass. Strong chemical recovery from acidification is found, attributed to large reductions in atmospheric deposition, moderated by catchment processing from land use and climate change. Browning counteracted chemical recovery in some regions, while Ca increased unexpectedly. We suggest that increased weathering, from enhanced te...
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Spatially resolved atmospheric gaseous elemental mercury (GEM) concentrations from an urban area in the Southern Hemisphere are reported for the first time.
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Environmental effects of microplastic are rather due to their adsorption capacity of contaminants than themselves. Aging is a key factor influencing adsorption properties of environmental microplastics. In order to clarify this influence,... more
Environmental effects of microplastic are rather due to their adsorption capacity of contaminants than themselves. Aging is a key factor influencing adsorption properties of environmental microplastics. In order to clarify this influence, polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) microplastics with particle sizes of <0.9 mm, 0.9–2 mm, and 2–5 mm were artificially aged in seawater for 12 months. This enabled an assessment of the change in Cu(II) adsorption capacity to the microplastics particles under aging. According to the FTIR spectra, fresh microplastics were oxidized during the UV induced aging process. The adsorption capacities of microplastic were positively correlated with their aging time. After 12-months aging, the amount of Cu(II) adsorbed to the aged microplastics was 1.45–2.92 times higher than on the fresh microplastic particles. For PP and PET, the aging effect increased with decreasing size of the microplastic particles. In the cas...
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Research Interests: Environmental Science, Climate Change, Saline Lake, Tibet, Environmental Monitoring, and 15 moreRivers, Water Chemistry, Medicine, Multidisciplinary, Heavy Metal, Water balance, Trace Elements, Anthropogenic impact, Tibetan Plateau, Spatial Variation, Trace element, Chemical Composition, Evaporite, Ions, and Drainage basin
Sediments act as a sink and a secondary source of contaminants, accounting for a central part of coastal and marine biogeochemical cycles. Phosphorus (P) is a macronutrient that governs primary productivity and phytoplankton growth, but... more
Sediments act as a sink and a secondary source of contaminants, accounting for a central part of coastal and marine biogeochemical cycles. Phosphorus (P) is a macronutrient that governs primary productivity and phytoplankton growth, but excess P influx results in algae bloom and deteriorates aquatic ecosystems. This study assesses seasonal fluctuations, spatial distribution and fractions of P in the sediments of the southern Caspian Sea. In this study, at eight sampling points, composite samples of the surface (from 0 to 10 cm) seabed sediments were collected at 10 and 30 m water depths. The sampling campaigns were carried out in the four seasons and a total of 64 sediment samples were obtained. Total organic matter (TOM), total P (TP) concentration and particle size distribution were determined. Then, P was fractionated using a four-step sequential procedure to quantify the loosely bound P (LP), the reductant soluble P (FeP), the metallic oxide-bound P (AlP) and the calcium carbonate (CaCO3) bound P (CaP). The inorganic P (IP) pool refers to the sum of LP, FeP, AlP and CaP, while the organic P (OP) was calculated by subtracting IP from TP.The results show that seasonal fluctuations of mean TP were statistically insignificant (p-value &gt; 0.05). Still, the highest levels were recorded in autumn (1555 mg kg-1), followed by winter (1405 mg kg-1), spring (1378 mg kg-1) and summer (1130 mg kg-1). These minor temporal variations in P levels are associated with the seasonal differences in the amount of runoff and the intensity of rivers discharging into the Caspian Sea, and thereby their sediment load and the physicochemical characteristics. The large riverine influx resulted in TP contamination hotspots in the river deltas of Anzali wetland, Babolrood and Sefidrud (northern Iran), where high loadings of suspended particles are discharged into the sea. The spatial TP distribution is thus site-specific and uneven. The main P fraction was CaP, reflecting the phosphate (PO43-) strong affinity for, and association with, calcium-bearing minerals. Only a minor fraction of P was determined as LP. The fraction of the mud-size particles was the main explanatory factor for the spatial distribution of overall low levels of non-residual (or bioavailable) P forms (i.e., LP, FeP and AlP) during spring and summer, while the sand fraction had the greatest explanatory value for the distribution of residual (non-bioavailable) P form (CaP) during autumn and winter. This study demonstrates that P bioavailability in sediments is mostly controlled by the physicochemical characteristics of the sediment material, which again is steered by seawater chemistry. A low content of bioavailable P fractions could therefore be related to the relatively low content of fine-grained (i.e. below 63 µm) particles in sediments of the southern Caspian Sea.
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Research Interests: Chemistry, Calcium, China, Acid Rain, Medicine, and 15 moreMultidisciplinary, Aluminum, Magnesium, Environmental monitoring and assessment, Acid Soil, Fresh water, Early Terrestrial Ecosystems, Acid Deposition, Cation Exchange Capacity, Forest Soil Ecology, Molar Ratio, Environmental, Acids, Partial Least Square, and Molar
We present long‐term changes in Norwegian lake water quality across regional gradients in atmospheric pollution, air temperature, hydrology, and vegetation using (a) a national representative lake survey carried out in 1995 and 2019... more
We present long‐term changes in Norwegian lake water quality across regional gradients in atmospheric pollution, air temperature, hydrology, and vegetation using (a) a national representative lake survey carried out in 1995 and 2019 (ThousandLakes), and (b) an annual lake survey from acid‐sensitive catchments (78 lakes, TrendLakes) from 1990 to 2020. Our analysis encompasses all major chemical constituents, for example, anions and cations, dissolved organic matter (DOM), nutrients, iron (Fe), and silicate (SiO2). During these decades, environmental changes included declines in sulfur (S) and nitrogen (N) deposition, climate warming, and increase in forest biomass. Strong chemical recovery from acidification is found, attributed to large reductions in atmospheric deposition, moderated by catchment processing from land use and climate change. Browning counteracted chemical recovery in some regions, while Ca increased unexpectedly. We suggest that increased weathering, from enhanced terrestrial productivity, is an important driver of increased Ca—substantiated by widespread, substantial increases in SiO2. Light‐ and nutrient‐limitation has become more prevalent, indicated by higher DOM, lower nitrate (NO3), and lower NO3to total phosphorous ratios. Declines in lake NO3 occurred independently of N deposition, suggesting increased catchment N retention, possibly from increased terrestrial productivity. We conclude that decreased air pollution continues to be a dominant driver of long‐term trends in lake chemistry, but climate‐induced increase in terrestrial weathering processes, governed by increased biomass, is likely to have an increasing impact on future lake acidity, nutrient, and light status, that may cascade along the aquatic continuum from rivers to the coast.
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This study assesses the occurrence of trace elements (TEs) in sediments of the southern Caspian Sea. A total of 16 shoreline sediment samples and 15 seabed sediment samples along five coastal transects were studied. The mean concentration... more
This study assesses the occurrence of trace elements (TEs) in sediments of the southern Caspian Sea. A total of 16 shoreline sediment samples and 15 seabed sediment samples along five coastal transects were studied. The mean concentration of TEs follows the order of Zn > V > Cr > Ni > Cu > Pb > Co > As > Sb > Mo > Cd. The TEs had an uneven, heterogeneous distribution within the shoreline and seabed sampling sites. This is due to that the study area comprises a large number of different pollution sources, also different sediment physicochemical characteristics. Levels of individual TEs within the seabed sediment transects were higher where their shoreline sites had higher concentrations, reflecting that the coastal sites play an important role in diffusing the contaminants towards the sea. The main anthropogenic source of TEs in this highly populated region, especially in the western part, is likely a large number of discharge points of greywater entering the sea. In addition, dominant fishing industry, tourism, intense agriculture, and textile and paper industry, as well as several other commercial activities, contribute significantly to the overall loading of TEs. Based on the statistical analyses, the organic matter and mud fraction had a strong explanatory value for the spatial variation of Cu, while oxyhydroxides of Fe and Mn had good explanatory factors to govern the spatial variation of other TEs. Pb and Zn had a relatively high partition coefficient (Kd), reflecting the affinity of these elements to be sorbed to the sediment phase. Cd and Sb had lower Kd, tending to remain in the aqueous phase. Geochemical indices indicated high enrichment of Cd, Sb, Zn, and Pb at a number of sampling sites, reflecting potential local sources of contamination. The Sisangan recreational area was identified as the most contaminated site. From a public health perspective, the non-carcinogenic risk of TEs was significant only at this site. The carcinogenic risks of Pb(II) and As(III) in adults, and Pb(II), Cd(II), and As(III) in children, were tolerable.
Research Interests: Environmental Science, Ecotoxicology, Environmental Monitoring, Environmental Chemistry, Environmental Pollution, and 13 moreMedicine, Biological Sciences, Environmental Sciences, Environmental Geochemistry, Transect, Sediment, Contamination, Sediment Contamination, Trace Elements, CHEMICAL SCIENCES, Shore, Seabed, and Aquatic Geochemistry
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Research Interests: Geography, Environmental Science, Oceanography, Chemistry, Earth, and 11 moreEnvironmental Chemistry, Medicine, Microplastics in the Oceans, Environmental Sciences, Sediment, CHEMICAL SCIENCES, Chemical Composition, Elsevier, Second Language Composition, Microplastics, and Medical and Health Sciences
Research Interests: Chemistry, Soil, Chromatography, Comparative Study, Medicine, and 15 moreMultidisciplinary, Sample Preparation, Environmental science and technology, Quantitative analysis, Aluminum, EDTA Chelation, Iron, Chemical Analysis, Fractionation, Inductively Coupled Plasma, Quantitative Analysis, Ion Exchange, Ion Exchange Resin, Elution, and cartridge
Research Interests: Environmental Science, Chemistry, Environmental Monitoring, China, Environmental Chemistry, and 15 moreAcid Rain, Medicine, Multidisciplinary, Atmospheric deposition, Damage Assessment, Cycling, Potassium, Ammonium, Soil Acidification, Forest Floor, Quaternary Ammonium Compounds, Soil Pollutants, Forest Canopy, Dry Deposition, and Field Measurement
Research Interests: Water, Biomass, Biology, Cyanobacteria, China, and 9 moreMedicine, Multidisciplinary, Water Supply, Drinking Water, ODOR, Nutrient, Odors, Ecosystem, and Seasons
Research Interests: Environmental Science, Bioaccumulation, China, Environmental Chemistry, Medicine, and 15 moreBiological Sciences, Cities, Environmental Sciences, Humans, Hair, Animals, Fishes, CHEMICAL SCIENCES, Megacity, Food Contamination, Environmental Toxicology and Chemistry, Food Chain, Geologic Sediments, Environmental Exposure, and Air Pollutants
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Research Interests: Chemistry, Soil, BIOCHAR, Environmental Chemistry, Medicine, and 13 moreMultidisciplinary, Adsorption, Charcoal, Sorption, Dissolved organic matter, Solubility, Dissolved Organic Carbon, Cation Exchange Capacity, Organic Matter, Amendment, Hydrogen-Ion Concentration, Soil Water, and Organic Chemicals
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Absorbency of UV and visible light by dissolved natural organic matter (DNOM) is used in proxies (sUVa, SAR) to assess its physiochemical characteristics and thereby removability of the DNOM by waterworks. The ongoing browning of surface... more
Absorbency of UV and visible light by dissolved natural organic matter (DNOM) is used in proxies (sUVa, SAR) to assess its physiochemical characteristics and thereby removability of the DNOM by waterworks. The ongoing browning of surface waters is partly due to increased concentration and change in characteristics of DNOM. However, it is also likely that the browning is partly due to the increased iron complexation by DNOM. The significance of absorbency by the Fe-DNOM complex needs to be assessed in order to distinguish between the drivers of brownification. key words – DNOM; Iron complex, adsorbency, sUVa, SAR
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Research Interests: Chemistry, Archives, Environmental Monitoring, China, Environmental Chemistry, and 15 moreMedicine, Multidisciplinary, Aluminum, Sequential Extraction, Field Study, Aluminium, Bayer Process, soil pH, Aqueous Solution, Forest Soil Ecology, Experimental Data, Field Data, Soil Water, Soil Pollutants, and gibbsite
Abstract Effects of mitigation measures in agriculture on abating eutrophication are difficult to evaluate by assessments of catchment monitoring data. Estimates of improved water quality by specific agricultural Best Management Practices... more
Abstract Effects of mitigation measures in agriculture on abating eutrophication are difficult to evaluate by assessments of catchment monitoring data. Estimates of improved water quality by specific agricultural Best Management Practices (BMPs) are therefore often dependent on simulation modeling. A main objective was thus to assess the probable reductions in total phosphorus (TP) loading achieved by implemented agricultural mitigation measures. The case-study site was a catchment in southeastern Norway. Simulation modeling was conducted by use of The Soil and Water Assessment Tool (SWAT). The aim of this present study was to understand the model uncertainty associated both with calibration/validation (baseline) and TP loading scenarios based on BMP. The modeled decrease in TP loading by the set of implemented BMPs was assessed by comparing simulated baseline output with output where the set of abatement actions were removed. The model was set up for the years 2006–2010 and calibrated against observed monitoring data, including daily discharge, sediment- and TP fluxes. Model simulations were performed including and excluding the implemented set of mitigation measures. The simulated set of mitigation measures include decrease in amount of phosphorus fertilization, establishment of vegetated buffer strips along streams and constructed wetlands in the water courses, no autumn tilling and removal of point TP sources from scattered dwellings. Model calibration and uncertainty estimation are performed using an algorithm for Sequential Uncertainty Fitting (SUFI2; ver. 2). Probabilistic risk for given magnitudes of increased TP loading if existing BMPs were not implemented was assessed. Using this novel approach it was possible to state, with a 80th percentile confidence level, that the average annual TP loading would have been about 26% higher if no mitigation measures were implemented in the catchment. This was possible to assess even though the difference between baseline and BMP scenario was not significant.
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... CATCHMENTS WITH DIFFERENT ACID DEPOSITION AND SITE CHARACTERISTICS NILS CHRISTOPHERSEN1, COLIN NEAL2, ROLF VOGT3, JACQUELINE M. ESSER4 and ... This brook is disturbed by beaver ponds which have created small marshes along the stream.... more
... CATCHMENTS WITH DIFFERENT ACID DEPOSITION AND SITE CHARACTERISTICS NILS CHRISTOPHERSEN1, COLIN NEAL2, ROLF VOGT3, JACQUELINE M. ESSER4 and ... This brook is disturbed by beaver ponds which have created small marshes along the stream. ...
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Research Interests: Environmental Science, Geochemistry, Chemistry, China, Methylmercury, and 15 moreEnvironmental Chemistry, Applied Geochemistry, Concentration, Far East, Flow, Discharge, Mercury, Contamination, Environmental Impact, Chine, Fresh water, Cinnabar, Fractionation, ENVIRONMENTAL SCIENCE AND MANAGEMENT, and Geometric mean
The occurrence of microplastic (MP) particles in shoreline sediments from the coastal region of the southern Caspian Sea, Mazandaran province, Iran, was investigated. A total of 312 MP items were visually detected in 17 sediment samples.... more
The occurrence of microplastic (MP) particles in shoreline sediments from the coastal region of the southern Caspian Sea, Mazandaran province, Iran, was investigated. A total of 312 MP items were visually detected in 17 sediment samples. The mean abundance of MP particles was 18 items kg-1. The MP particles were mainly fibers, and black color dominated. The dominant size class of MP particles was between 250 and 500 μm. Polyethylene terephthalate (PET), polystyrene (PS), and nylon (NYL) were the major polymers and/or copolymers comprising MP particles in both sediment samples. The number of MP particles in sediment samples showed a general decrease from west to east in the study area. This may be reflecting the spreading of MP loading from the outlets of Sefidrud, Tonekabon, Chalus, the major rivers entering the Caspian Sea just west of the study area, and the overall decrease in the spatial distribution of touristic and fishery activity.