| 1. |
- Bodin, Hristina, et al.
(författare)
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Attenuation of pharmaceutical substances : phytoremediation using constructed wetlands
- 2018
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Ingår i: 13th Society of Wetland Scientists (SWS) Europe Chapter Meeting. ; , s. 19-22
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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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| 2. |
- Cardoso Chrispim, Mariana, Postdoktor, 1990-, et al.
(författare)
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A framework for resource recovery from wastewater treatment plants in megacities of developing countries
- 2020
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Ingår i: Environmental Research. - Maryland Heights : Academic Press. - 0013-9351 .- 1096-0953. ; 188
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Tidskriftsartikel (refereegranskat)abstract
- In developing countries, there is often a lack of a comprehensive data set that supports the development of coherent policies on resource recovery from wastewater treatment. This paper aims to contribute to the elaboration of resource recovery projects by providing accurate and updated data from wastewater treatment plants such as those located in the region of the Macrometropolis of Sao Paulo. The authors discuss possibilities of improvement of resource recovery for this illustrative example. Comprehensive analyses were performed based on data from 143 municipal wastewater treatment plants to understand the situation regarding resource recovery implementation in this region. The results show that just 26% of the plants perform at least one resource recovery practice. The predominant resource recovery practice is internal water reuse, and recovery is concentrated more in large plants than in medium and small ones. The sludge is disposed in landfills except for three plants, which perform sludge recycling for compost. Some plant managers reported interest in recovering energy from biogas, in expanding water reuse and in recovering sludge for fertilizer production or for building materials. Several aspects that have been regarded as relevant to the implementation of resource recovery processes in previous literature are discussed, such as the size of the plant, related legislation as well as treatment technologies and configurations. Finally, the authors propose a generic framework with several steps that can help to achieve resource recovery implementation. Therefore, the results can provide support for planning of resource recovery projects for large cities in developing countries. © 2020 Elsevier Inc.
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| 3. |
- Cardoso Chrispim, Mariana
(författare)
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Resource recovery from wastewater treatment: challenges, opportunities and guidance for planning and implementation
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Considering the current resources scarcity, Wastewater Treatment Plants (WWTP) should be adapted to become more sustainable. For example, it is possible to recover resources present in municipal wastewater. However, regional studies about integration of resource recovery processes at different scales or about the main barriers to implementation in developing countries are missing in the literature. Also, there is a need for planning methodologies to identify the most sustainable solution in each context. Understanding the current situation is an essential step to support planning and accelerate resource recovery implementation. To address these issues this thesis aims to guide planning, technology and policy development towards resource recovery from municipal WWTP in large cities of developing countries. This thesis presents a comprehensive knowledge base for wastewater treatment plant managers and decision-makers leading to a better understanding of resource recovery solutions and the actions needed to facilitate implementation. The methodology comprised critical literature reviews and two case studies. Secondary data from literature and primary data (obtained through questionnaires) were collected and analysed. Megacities in developing countries are analysed in the papers, with the focus on the Macrometropolis of Sao Paulo, which is the most populous area in the Southern Hemisphere. The current situation shows a low implementation of resource recovery practices in the region, and local conditions affect the implementation of water reuse, and nutrients and energy recovery. A framework consisting of eleven steps is proposed to support planning and decision-making on resource recovery from wastewater. This new tool was tested and can be applied by decision-makers in wastewater sector for better operation and management. Market, legislation, local economic development, and cooperation with stakeholders are relevant aspects covered in the analysis. There is a great potential to expand wastewater treatment integrated with nutrient and energy recovery strategies in developing countries. Potentials for phosphorus and energy recovery were estimated and some recovery scenarios are recommended. In conclusion, the findings can help planning and elaboration of resource recovery projects in wastewater treatment in urban areas and stimulate creation of public policies. The main research gaps identified in this thesis can guide further research and technological development in this field.
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| 4. |
- Johannesson, Karin, 1982-, et al.
(författare)
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Temporal phosphorus dynamics affecting retention estimates in agricultural constructed wetlands
- 2017
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Ingår i: Ecological Engineering. - Amsterdam : Elsevier. - 0925-8574 .- 1872-6992. ; 103, s. 436-445
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 5. |
- Song, Xiaojun, et al.
(författare)
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Effects of Water Depth and Phosphorus Availability on Nitrogen Removal in Agricultural Wetlands
- 2019
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Ingår i: Water. - Basel : MDPI. - 2073-4441. ; 11:12
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Tidskriftsartikel (refereegranskat)abstract
- 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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| 6. |
- Waara, Sylvia, 1958-, et al.
(författare)
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Distribution and removal efficiency of heavy metals in two constructed wetlands treating landfill leachate
- 2011
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Ingår i: Water Science and Technology. - London : IWA Publishing. - 0273-1223 .- 1996-9732. ; 64:8, s. 1597-1606
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Tidskriftsartikel (refereegranskat)abstract
- The results of heavy metals (Fe, Mn, Zn, Ni, Cu, Cr, Pb, Cd) removal and partitioning between aqueous and solid phases at two treatment wetlands (TWs) treating municipal landfill leachates are presented. One of the TWs is a surface flow facility consisting of 10 ponds. The other TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal sub-surface flow. The metals concentrations were analysed in leachate (both TWs) and bottom sediments (surface flow TW). Very high (90.9-99.9%) removal rates of metals were observed in a mature surface flow TW. The effectiveness of metals removal in a newly constructed pilot-scale sub-surface flow wetland were considerably lower (range 0-73%). This is attributed to young age of the TW, different hydraulic conditions (sub-surface flow system with much shorter retention time, unoxic conditions) and presence of metallic complexes with refractory organic matter
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| 7. |
- Waara, Sylvia, et al.
(författare)
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Performance of a constructed wetland system for treatment of landfill leachate.
- 2008
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Ingår i: Waste 2008. Waste and Resource management-A shared responsibility. - Stanton-on-the-Wolds : Waste Conference Ltd.. ; , s. 655-667, s. 655-667
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Konferensbidrag (refereegranskat)abstract
- The performance of a constructed wetland for treatment of landfill leachate has been evaluated based upon data obtained during 4 years (2003-2006). It consists of a series of 10 ponds with a total capacity of 52.000 m3 covering 8 ha. Using univariate and multivariate statistics (PCA) the reduction pattern of a large number of chemical parameters including heavy metals has been investigated in 3 parts of the wetland with equal volume. Analyses show that many parameters are removed to the greatest extent in the first part of the system (e.g. many heavy metals, total suspended solids) or the second part of the system (N-NH4) while other parameters such as total nitrogen are more gradually reduced (10 ton/year removed). Toxicity testing with 5 bioassays showed that toxicity was sometimes observed at the inlet but no toxicity was observed at the outlet for 4 of the test species. The data presented will be used for optimizing the treatment process as well as to improve the monitoring program.
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| 8. |
- Waara, Sylvia, 1958-, et al.
(författare)
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Treatment of landfill leachate in a constructed free water surface wetland system over a decade – Identification of disturbance in process behaviour and removal of eutrophying substances and organic material
- 2019
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Ingår i: Journal of Environmental Management. - London, UK : Academic Press. - 0301-4797 .- 1095-8630. ; 249
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Tidskriftsartikel (refereegranskat)abstract
- An 8 ha free water surface wetland system in Orebro, Sweden, which has sediment traps followed by 10 ponds for treatment of landfill leachate in the methanogenic stage, was studied from 2003 to 2012. The wetland was irregularly loaded and the leachate characteristics showed high temporal and spatial variability, so Multivariate Statistical Process Control was chosen as the diagnostic tool for detecting anomalies prior to assessing removal efficiency for eutrophying substances and organics. Disturbances in process behaviour included those due to intermittent flow, dilution due to snowmelt, an episode of high pollutant load, and sampling technique. The wetland total nitrogen mass removal was 89%, resulting in a first order rate coefficient of 1.7 m/year. Total phosphorus mass removal was 98%, while mass reduction was lower for TOC (60%), although this was still below discharge limits. The low amount of labile organic material and phosphate are probably the main reasons for the low denitrification rate. © 2019 Elsevier Ltd. All rights reserved.
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| 9. |
- Weisner, Stefan, 1954-, et al.
(författare)
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National Large-Scale Wetland Creation in Agricultural Areas—Potential versus Realized Effects on Nutrient Transports
- 2016
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Ingår i: Water. - Basel : MDPI. - 2073-4441. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- 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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