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  • 1.
    Berglund, Björn
    et al.
    Linköping University, Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping, Sweden.
    Khan, Ghazanfar Ali
    Department of Chemistry, Umeå University, Umeå, Sweden.
    Weisner, Stefan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Fick, Jerker
    Department of Chemistry, Umeå University, Umeå, Sweden.
    Lindgren, Per-Eric
    Linköping University, Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping, Sweden.
    Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 476-477, p. 29-37Article in journal (Refereed)
    Abstract [en]

    Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng x 1(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes. (c) 2014 Elsevier B.V. All rights reserved.

  • 2.
    Bodin, Hristina
    et al.
    Division of Natural Sciences, Kristianstad University, Kristianstad, Sweden.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Attenuation of Pharmaceutical Substances: Phytoremediation using Constructed Wetlands2018In: 13th Society of Wetland Scientists (SWS) Europe Chapter Meeting: Management of Wetland Ecosystem Services: Issues, Challenges and Solutions, 2018, p. 19-22Conference paper (Refereed)
    Abstract [en]

    Introduction: Currently, wastewater treatment plants (WWTPs) do not efficiently remove pharmaceutical substances (PS). Thus, such substances are now frequently found in aquatic ecosystems worldwide. Also, concentrations of some PS in treated effluents exceed Environmental Quality Standards proposed by EU legislation. One resource-efficient option for increasing PS removal in WWTP effluents is to use constructed wetlands (CWs) as an attenuation step (Breitholtz et al. 2012; Li et al. 2014). However, very little research has been done on how to maximize the PS attenuation capacity of CWs. Therefore, a project with the aim to investigate reduction of different pharmaceutical substances in CWs with different vegetation compositions and water depths, was performed at the Experimental Wetland Area (EVA) located 20 km north of Halmstad, Sweden. 

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  • 3.
    Bodin, Hristina
    et al.
    Linköping University, Linköping, Sweden.
    Mietto, Anna
    University of Padova, Legnaro, Italy.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Persson, Jesper
    Swedish University of Agricultural Sciences, Alnarp, Sweden.
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Tracer behaviour and analysis of hydraulics in experimental free water surface wetlands2012In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 49, p. 201-211Article in journal (Refereed)
    Abstract [en]

    Effects of inlet design and vegetation type on tracer dynamics and hydraulic performance were investigated using lithium chloride in 18 experimental free water surface wetlands. The wetlands received similar water flow but had different vegetation types: 6 emergent vegetation wetlands (EVWs), 6 submerged vegetation wetlands (SVWs) and 6 free development wetlands (FDWs). Two types of inlet designs were applied: half of each wetland vegetation type had a barrier near the inlet to help distribute incoming tracer solution, while the rest had no barrier. Residence time distribution (RTD) functions were calculated from tracer data using two techniques: method of moments and a novel Gauss modelling approach. RTD functions were used to quantify hydraulic parameters: active wetland volume (e-value), water dispersion (N-value) and hydraulic efficiency (lambda-value). For wetlands without barrier, significantly lower tracer mass recoveries were found from EVWs compared to FDWs and SVWs, signifying a risk of tracer methodological problems in small densely vegetated wetlands. These problems were minimized in wetlands with an inflow construction promoting distribution of incoming tracer solution. Compared to the method of moments, Gauss modelling seemed to produce more reliable lambda-values but less reliable N-values. Data for precise hydraulic quantification were lost by Gauss modelling, as indicated by overall lower variance in these data sets and lower mass recoveries. However, Gauss modelling may minimize uncertainties associated with lithium immobilization/mobilization. Parameters were significantly affected by the RTD data analysis method, showing that the choice of method could affect evaluation of wetland hydraulics. The experimental wetlands in this study exhibited relatively high e-values and low N-values. This was probably caused by the small size of the wetlands and low water flow velocities, emphasizing that hydraulic parameter values obtained in small experimental wetlands may not be applicable to hydraulics in larger wetlands. The method of moments revealed lower e-values from EVWs compared to SVWs and FDWs. It was indicated that lower e-values were mainly caused by vegetation volumes. This highlighted a need for regular maintenance to secure efficient treatment volume in wetlands with dense vegetation. © 2012 Elsevier B.V.

  • 4.
    Ehde, Per Magnus
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Nutrient retention in constructed wetlands in an agricultural landscape in southwest Sweden2007In: 2nd International Symposium on Wetland Pollutant Dynamics and Control - WETPOL 2007: extended abstracts, Tartu: University of Tartu, 2007, p. 91-92Conference paper (Other academic)
  • 5.
    Ehde, Per Magnus
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Weisner, Stefan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    The influence of vegetation on nitrogen retention in a long-term experimental wetland study2009In: Proceedings of the 3rd Wetland Polluntat Dynamics and Control - WETPOL 2009 - Barcelona / [ed] Josep M. Bayona & Joan García, 2009, p. 197-198Conference paper (Refereed)
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  • 6.
    Eller, Franziska
    et al.
    Department of Biology, Aarhus University, Aarhus, Denmark.
    Ehde, Per Magnus
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Oehmke, Claudia
    Institute of Botany and Landscape Ecology, Partner in the Greifswald Mire Center, University of Greifswald, Greifswald, Germany.
    Ren, Linjing
    Department of Biology, Aarhus University, Aarhus, Denmark & Biocenter Klein Flottbek, Hamburg University, Hamburg, Germany.
    Brix, Hans
    Department of Biology, Aarhus University, Aarhus, Denmark.
    Sorell, Brian K.
    Department of Biology, Aarhus University, Aarhus, Denmark.
    Weisner, Stefan
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Biomethane yield from different European Phragmites australis genotypes, compared with other herbaceous wetland species grown at different fertilization regimes2020In: Resources, ISSN 2079-9276, Vol. 9, no 5, article id 57Article in journal (Refereed)
    Abstract [en]

    Phragmites australis, Typha latifolia, T. angustifolia and Arundo donax are tall wetland graminoids with the potential to replace fossil fuels under sustainable cultivation conditions. We investigated the biomethane (CH4) production of these four species, including four different genotypes of P. australis, which represent the high intraspecific diversity of European reed. All plants were grown under three different macronutrient supplies (no nutrients added, an equivalent of 75 kg N ha−1 year−1 added and an equivalent of 500 kg N ha−1 year−1 added). Biomethane production was measured in four independent batch digestion tests. Across all experiments, fertilization regime had little effect on CH4 yield, which was on average 222 ± 31 L kg−1 volatile solids (VS). The lowest yield was produced by T. angustifolia (140 L kgVS−1) receiving no nutrients, while the highest yield was produced by A. donax (305 L kgVS−1) in the highest nutrient treatment. The intraspecific diversity of P. australis did not affect biomethane production. All P. australis genotypes produced on average 226 ± 19 L CH4 kgVS−1, which, although high, was still lower than conventional biogas species. The biomass production of P. australis was less increased by fertilization than that of Typha sp. and A. donax, but all species had similar biomass without fertilization.

  • 7.
    Johannesson, Karin M.
    et al.
    IFM Biology, Linköping University, Linköping, Sweden.
    Tonderski, Karin S.
    IFM Biology, Linköping University, Linköping, Sweden.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan E. B.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Temporal phosphorus dynamics affecting retention estimates in agricultural constructed wetlands2017In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 103, no Part B, p. 436-445Article in journal (Refereed)
    Abstract [en]

    Data from seven constructed wetlands (CWs) in the south of Sweden were analyzed to investigate the effects of water flow and season on inflow phosphorus (P) concentrations and temporal P retention variations in CWs receiving runoff from arable land. The form of P (dissolved or particulate) during different water flows (high and low) and seasons (warm and cold) was investigated using the results of total P (TP) and phosphate analyzed in grab samples that had been collected regularly or occasionally during two to nine years, along with continuous water flow measurements.

    The form of inflow and outflow P (particulate or dissolved P) differed between CWs, and also varied with season and flow. For instance, in three of the CWs, particulate P (PP) dominated the inflow during the cold period with high flow, while during the other periods the proportion of PP was approximately 50%. In one CW situated in a catchment with high clay content, PP dominated both inflow and outflow at all times. The average clay content in catchment top soils was positively correlated to the flow-weighted inflow TP concentrations.

    In three CWs receiving runoff through drainage pipes, the relationship between TP concentrations (TPin) and water flow was positive, both during high and low flow, and during warm and cold period. However, in four CWs that received surface water runoff, the relationship between TPin and water flow was positive during high flow periods (i.e. the 25% sampling occasions with the highest flow), and during low flow and warm period, the relationship was negative in these four wetlands, indicating either anoxic stagnant water upstream or influence from rural wastewater.

    The temporal dynamics of P concentrations mean that in some of the CWs, the main part of the annual P retention may occur during a few days with high water flows. The correlation between concentration and water flow suggests that the water sampling strategy may have a considerable impact on retention estimates, as exemplified by some calculation examples. © 2015 Elsevier B.V.

  • 8.
    Johannesson, Karin
    et al.
    Institutionen för fysik, kemi och biologi, Ekologi, Linköpings universitet, Linköping, Sverige.
    Tonderski, Karin
    Institutionen för fysik, kemi och biologi, Ekologi, Linköpings universitet, Linköping, Sverige.
    Wedding, Bengt
    Ekologgruppen i Landskrona AB, Landskrona, Sverige.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Phosphorus load variations and retention in non-point source wetlands in southern Sweden2011Manuscript (preprint) (Other academic)
    Abstract [en]

    Data from seven constructed wetlands receiving runoff from agricultural catchments in the south of Sweden were investigated with respect to phosphorus (P) retention. The seven wetlands differed in size (0.22-2 ha), design, land use and catchment characteristics. The hydraulic load varied between 7 and 725 m yr-1, which reflect the different geographical and hydrological conditions. The overall aim of this study was to increase the understanding of how water flow and inflow P concentration varations affect the P retention in constructed wetlands receiving runoff from arable land. Water flow was measured continuously, and time or flow proportional water samples were taken. Grab samples were taken during high flow periods and also to supplement the automatic water sampling. P retention varied between wetlands, from 1 to 58 kg ha-1 yr-1, and was correlated to the P load (R2=0.9, p<0.05). P retention in the wetlands varied strongly between years, and negative retention was recorded for some years and wetlands. When investigating monthly retention for each wetland, release of P corresponded to either high flow or possible anoxic conditions during low-flow periods in summer or during winter when ice covered the wetlands. Analyses of grab samples revealed a relationship between TP concentration and water flow for most wetlands. In some wetlands, P was transported mainly as particulate P (PP), but in other wetlands, soluble P was the dominating form in both inflow and outflow. Incoming concentrations varied greatly between wetlands (1-2000 μg l-1) which reflected the different catchment characteristics, e.g. land use, soil type and topography.

  • 9.
    Kallner Bastviken, Sofia
    et al.
    IFM Biology, Linköping University, Campus Valla, Sweden.
    Weisner, Stefan E.B.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Thiere, Geraldine
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Svensson, Jonas M.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Tonderski, Karin S.
    IFM Biology, Linköping University, Campus Valla, Sweden.
    Effects of vegetation and hydraulic load on seasonal nitrate removal in treatment wetlands2009In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 35, no 5, p. 946-952Article in journal (Refereed)
    Abstract [en]

    Optimising nitrate removal and identifying critical factors for nitrate removal in wetlands is an important environmental task in the effort to achieve better surface water quality. In this study, eighteen free water surface wetlands with similar shape and size (22 m2 each) received groundwater with a high nitrate-N concentration (about 11 mg l−1). The effects of two hydraulic loads, 0.13 m d−1 and 0.39 m d−1, and three vegetation types – emergent, submersed and freely developing vegetation – on the nitrate-N removal were investigated through mass inflow and outflow measurements.

    No significant difference in nitrate removal between the different hydraulic loads could be detected. Significantly higher area-specific nitrate removal and first-order area-based rate coefficients were found in the basins with emergent vegetation, with no difference between the basins with submersed and freely developing vegetation. The nitrate-N removal increased as the wetlands matured and the vegetation grew denser, emphasizing the role of dense emergent vegetation for nitrate removal at high nitrate concentrations.

  • 10.
    Martens, Mireille
    et al.
    Water Technology Group, HZ University of Applied Sciences, Vlissingen, the Netherlands.
    Karlsson, Niklas
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Ehde, Per Magnus
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Mattsson, Marie
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    The greenhouse gas emission effects of rewetting drained peatlands and growing wetland plants for biogas fuel production2021In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 277, article id 111391Article in journal (Refereed)
    Abstract [en]

    Efforts to mitigate greenhouse gas (GHG) emissions are receiving increased attention among governmental and commercial actors. In recent years, the interest in paludiculture, i.e. the use of rewetted peatlands, has grown because of its potential to reduce GHG emissions by stopping soil decomposition. Moreover, cultivating wetland plants on rewetted peatlands for  bioenergy production that replaces fossil fuels in the transport sector, can contribute to additional GHG emission reductions. In this study, an analysis of literature data was conducted to obtain data on GHG emissions (CO2 and CH4) and biomass production from rewetted peatlands cultivated with two different wetland plant species: Phragmites australis (Pa) and Typha latifolia (Tl). In  addition, a  biogas experiment was carried out to investigate the biomethane yield of Pa and Tl biomass, and the reduction of global warming potential (GWP) by using biomethane as vehicle fuel. The results show that peatland rewetting can be an important measure to mitigate the GWP as it reduces GHG emissions from the soil, particularly on a 100-year timescale but also to some extent on a 20-year timescale. More specifically, rewetting of 1 km2 of peatland can result in  a  GWP reduction corresponding to  the  emissions from ±2600 average sized petrol cars annually. Growing Pa on rewetted peatlands reduces soil GHG emissions more than growing Tl, but Pa and Tl produced similar amounts of biomass and biomethane per land area. Our study concludes that Pa, because of a more pronounced GWP reduction, is the most suitable wetland plant to cultivate after peatland rewetting. © 2020 The Author(s). Published by Elsevier Ltd.

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  • 11.
    Nilsson, Josefin E.
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS). Linnaeus University, Kalmar, Sweden.
    Liess, Antonia
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Will planting of surface-flow wetlands improve nitrogen removal in the long run?2019In: Book of Abstracts: 8th International Symposium on Wetland Pollutant Dynamics and Control. 17 – 21 June, 2019. Aarhus University, Denmark / [ed] Carlos A. Arias, Carlos A. Ramírez-Vargas, Lorena Peñacoba-Antona & Hans Brix, Aarhus: Aarhus Universitetsforlag, 2019, p. 340-340Conference paper (Other academic)
    Abstract [en]

    Initial planting of created wetlands is common practice in order to, for instance, improve nitrogen (N) removal. It has been shown that vegetated surface-flow wetlands remove more N than non-vegetated surface-flow wetlands. However, changes in N removal as differently vegetated wetlands progress from an early successional stage to a mature system are less investigated.

    In our study, we followed three different wetland types of initial planting over the course of 12 years, with the aim to examine how planting of newly created wetlands affects long-term N removal. All our data were collected in the experimental wetland facility near Halmstad in south-western Sweden. The facility consist of 18 small (ca. 25 m2) surface-flow wetlands, equal in age, shape and size. At the time of creation, the 18 wetlands were randomly divided into three types. One type was then planted with emergent vegetation, one was planted with submerged vegetation and the last type was left unplanted for free development. Succession of vegetation was thereafter allowed to progress uninhibited in all wetlands.

    Our results confirmed that emergent vegetation wetlands initially removed more N than submerged vegetation and free development wetlands. In addition, our results showed that N removal in submerged vegetation and free development wetlands increased with ecosystem age, whereas N removal in emergent vegetation wetlands did not. N removal in all three wetland vegetation types converged when the wetlands reached a more mature state, around year 9 after wetland creation. However, although all wetlands contained emergent vegetation in year 9, proportion cover of emergent vegetation and vegetation composition still differed substantially between wetland types.

    We therefore conclude planting of created surface-flow wetlands with emergent vegetation will have a positive effect on N removal, but only during an early successional stage. Our study indicates it is not the emergent vegetation per se which results in higher N removal in more mature wetlands, but the maturation process in itself, since mature wetlands with different emergent vegetation cover achieved similar N removal. Initial planting will not result in higher N removal once the system has reached maturity.

  • 12.
    Nilsson, Josefin E.
    et al.
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Liess, Antonia
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Ehde, Per Magnus
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan E.B.
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Mature wetland ecosystems remove nitrogen equally well regardless of initial planting2020In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 716, article id 137002Article in journal (Refereed)
    Abstract [en]

    Restored and constructed semi-natural wetlands are increasingly used in the agricultural landscape to intercept nutrients from surface waters. Vegetated surface-flow wetlands remove more nitrogen (N) than those without vegetation. However, changes in N removal over time as differently vegetated wetlands progress from early successional stages to mature systems are less investigated. We monitored three different types of initial planting over the course of 12 years, with the aim to examine how planting of newly constructed wetlands affects long-term N removal. All our data were collected in an experimental wetland facility in south-western Sweden. The facility consists of 18 identical small (ca. 25 m2) surface-flow wetlands, simulating semi-natural wetlands in an agricultural landscape. Initially, the 18 wetlands were randomly divided into three treatments (vegetation types) with six replicates each and planted with (1) emergent vegetation, (2) submerged vegetation and (3) no vegetation for free development. Vegetation succession afterwards progressed uninhibited in all wetlands. Emergent vegetation wetlands initially removed more N than both submerged vegetation and free development wetlands. We found that N removal in submerged vegetation and free development wetlands increased with ecosystem age, whereas N removal in emergent vegetation wetlands did not. N removal in all three vegetation types converged when the wetlands reached a more mature state, around 8 years after wetland construction. However, although all wetlands contained emergent vegetation in year 8, the proportion of emergent vegetation cover and vegetation composition still differed substantially between wetland types. Our study indicates that it is not the cover of emergent vegetation per se which promotes higher N removal in more mature wetlands, but the maturation process itself; mature wetlands despite differing emergent vegetation coverage achieved equally high N removal. In conclusion, once wetlands reach maturity, beneficial effects of initial planting on N removal disappear. © 2020 The Authors. Published by Elsevier B.V.

  • 13.
    Song, Xiaojun
    et al.
    Halmstad University, School of Business, Engineering and Science. School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, China.
    Ehde, Per Magnus
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Weisner, Stefan
    Halmstad University, School of Business, Innovation and Sustainability, The Rydberg Laboratory for Applied Sciences (RLAS).
    Effects of Water Depth and Phosphorus Availability on Nitrogen Removal in Agricultural Wetlands2019In: Water, E-ISSN 2073-4441, Vol. 11, no 12, article id 2626Article in journal (Refereed)
    Abstract [en]

    Excess nitrogen (N) from agricultural runoff is a cause of pollution inaquatic ecosystems. Created free water surface (FWS) wetlands can be used as buffering systems to lower the impacts of nutrients from agricultural runoff. The purpose of this paper was to evaluate critical factors for N removal in FWSwetlands receiving high nitrate (NO3) loads from agriculture. The study was performed in 12 experimental FWS wetlands in southern Sweden, receiving drainage water from an agricultural field area. The effects of water depth (mean depth of 0.4 m and 0.6 m, respectively) and phosphorus (P) availability (with or without additional P load) were investigated from July to October. The experiment was performed in a two-way design, with three wetlands of each combination of depth and P availability. The effects of P availability on the removal of NO3 and total N were strongly significant, with higher absolute N removal rates per wetland area (g m−2 day−1) as well as temperature-adjusted first-order area-based removal rate coefficients (Kat) in wetlands with external P addition compared to wetlands with no addition. Further, higher N removal in deep compared to shallow wetlands was indicated by statistically significant differences in Kat. The results show that low P availability may limit N removal in wetlands receiving agricultural drainage water. Furthermore, the results support that not only wetland area but also wetland volume may be important for N removal. The results have implications for the planning, location, and design of created wetlands in agricultural areas. © 2019 by the authors

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  • 14.
    Waara, Sylvia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Gajewska, Magdalena
    Gdańsk University of Technology, Gdańsk, Poland.
    Dvarioniene, Jolanta
    Kaunas University of Technology, Kaunas, Lithuania.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Gajewski, Ryszard
    Gdańska Infrastructura Wodociągowo-Kanalizacyjna, Gdańsk, Poland.
    Grabowski, Pawel
    Grupa Lotos, Gdańsk, Poland.
    Hansson, Anna
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Kaszubowski, Jacek
    Gdańska Infrastructura Wodociągowo-Kanalizacyjna, Gdańsk, Poland.
    Obarska-Pempkowiak, Hanna
    Gdańsk University of Technology, Gdańsk, Poland.
    Przewlócka, Maria
    Gdańsk University of Technology, Gdańsk, Poland.
    Pilecki, Adam
    Grupa Lotos, Gdańsk, Poland.
    Nagórka-Kmiecik, Dagmara
    City Hall of Gdańsk, Environment Department , Gdańsk, Poland.
    Skarbek, Jacek
    Gdańska Infrastructura Wodociągowo-Kanalizacyjna, Gdańsk, Poland.
    Tonderski, Karin
    Linköping University, Linköping, Sweden.
    Weisner, Stefan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Wojciechowska, Ewa
    Gdańsk University of Technology, Gdańsk, Poland.
    Towards Recommendations for Design of Wetlands for Post-Tertiary Treatment of Waste Water in the Baltic Sea Region – Gdańsk Case Study2014Conference paper (Other academic)
    Abstract [en]

    There are many challenges that need to be addressed if the far reaching objectives on high environmental status as required in the EU Water Framework Directive and the Marine Strategy Framework Directive will be met in the Baltic Sea Region within the next decade. For wastewater treatment plants (WWTP) this implies, in spite of the many improvements made during the last decade, development and introduction of new technology to further reduce eutrophying compounds, hazardous chemicals and pharmaceuticals. Constructed wetlands when properly designed and operated have been shown to be robust systems with low energy requirements that may not only reduce many types of pollutants but may also provide many additional ecosystem services beyond requirements generally imposed by authorities. For example, they may support and enhance biodiversity and be used to convert brownfield areas in urban landscapes to recreational areas. Reduced cost is possible if treated water is reused in industry or for irrigation. In a project, supported by the Swedish Institute, a group of scientists, a water company and water using industry has together with local authorities through workshops, field studies and literature studies worked on finding a general first recommendation on design and operation. In this paper we will present the scientific rational and legal constraints for the general design and operation of a wetland system for post-tertiary treatment of waste water from WWTPs using Gdańsk as an example. The proposal includes a first part, which mainly will be focusing on pollutant and pathogen removal using particle traps and a HSSF wetland on land owned by the WWTP and a second part consisting of a FWS wetland which, in addition to further polishing the water, will enhance biodiversity and provide recreational areas on derelict land owned by the city.

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  • 15.
    Weisner, Stefan E.B
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Bastviken Kallner, Sofia
    Department of Biology, Linköping University.
    Thiere, Geraldine
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Tonderski, Karin S.
    Department of Biology, Linköping University.
    Influence of alternative states on nitrogen removal in experimental wetlands2007In: 2nd International Symposium on Wetland Pollutant Dynamics and Control - WETPOL 2007: extended abstracts / [ed] Mander Ülo, Koiv Margi, Vohla Chrisitna, Tartu: Institute of Geography, University of Tartu , 2007, p. 357-359Conference paper (Other academic)
    Abstract [en]

    Denitrification is the main process that remove nitrate from the water in wetlands. Plants can supply denitrifying bacteria with organic carbon and suitable attachment surfaces (Weisner et al. 1994). They also promote the development of anaerobic conditions through litter accumulation and decomposition, which would favour denitrification. The presence of plants has been shown to enhance nitrate removal in field studies (Bachand and Horne 2000). Toet et al. (2005) found a higher nitrogen removal in wetland compartments with emergent plants than with submersed plants. Results from microcosm studies have shown that the potential for denitrification is specific for different plant species (Bastviken et al. 2005).

    Wetlands may typically exist in alternative states, dominated by different kinds of vegetation. The purpose of this study was to investigate the effect of alternative state on nitrogen removal under controlled conditions in experimental wetlands.

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  • 16.
    Weisner, Stefan E.B.
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Strand, John A.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Sahlén, Göran
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Thiere, Geraldine
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Svensson, Jonas M.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Combating eutrophication and biodiversity loss in Sweden: importance of constructed wetlands in the agricultural landscape2007In: Multifunctions of wetland systems, Padua: PAN , 2007, p. 60-61Conference paper (Other academic)
    Abstract [en]

    The results of this evaluation show that constructed wetlands in the agricultural landscape are capable of a substantial reduction of the nutrient transport to downstream recipients, but only if properly located. These wetlands will also contribute to an increased biodiversity even if not planned primarily for this purpose. The use of wetlands for multiple functions needs to be developed to motivate large-scale wetland construction.

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  • 17.
    Weisner, Stefan
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Johannesson, Karin
    IFM Biology, Linköping University, Linköping, Sweden.
    Thiere, Geraldine
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Svengren, Henrik
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Ehde, Per Magnus
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Tonderski, Karin S.
    IFM Biology, Linköping University, Linköping, Sweden.
    National Large-Scale Wetland Creation in Agricultural Areas—Potential versus Realized Effects on Nutrient Transports2016In: Water, E-ISSN 2073-4441, Vol. 8, no 11, article id 544Article in journal (Refereed)
    Abstract [en]

    During 2007–2013, the Swedish Board of Agriculture granted support within a national program to about 1000 wetlands, corresponding to a 5300-hectare wetland area, with the dual goal to remove nutrients from water and to improve biodiversity in agricultural landscapes. The aim of the present study was to compare the effects on nutrient transports that are realized within the national program to what could be obtained with the same area of wetlands if location and design of wetlands were optimized. In single, highly nutrient-loaded wetlands, a removal of around 1000 kg nitrogen and 100 kg phosphorus per hectare wetland area and year was estimated from monitoring data. Statistical models were developed to estimate the overall nutrient removal effects of wetlands created within the national program. Depending on model, the effect of the national program as a whole was estimated to between 27 and 38 kg nitrogen and between 2.7 and 4.5 kg phosphorus per hectare created wetland area and year. Comparison of what is achieved in individual wetlands to what was achieved in the national program indicates that nutrient removal effects could be increased substantially in future wetland programs by emphasising location and design of wetlands.

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  • 18.
    Weisner, Stefan
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Mietto, Anna
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Persson, Jesper
    Swedish University of Agricultural Sciences, Alnarp, SWEDEN.
    Influence of vegetation on hydraulics in experimental surface-flow wetlands2009In: 3rd Wetland Pollutant Dynamics and Control - WETPOL 2009 - Barcelona / [ed] Josep M. Bayona & Joan García, 2009, p. 179-180Conference paper (Refereed)
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