| 1. |
- Bojcevska, Hristina, 1977-, et al.
(author)
-
Impact of loads, season, and plant species on the performance of a tropical constructed wetland polishing effluent from sugar factory stabilization ponds
- 2007
-
In: Ecological Engineering. - 0925-8574 .- 1872-6992. ; 29:1, s. 66-76
-
Journal article (peer-reviewed)abstract
- The effects of wastewater loading rates and two macrophyte species on treatment of sugar factory stabilization pond effluent were investigated in a pilot-scale free water surface constructed wetland (FWS CW) system in western Kenya. For 12 months, four CWs were operated at a hydraulic loading rate of 75 mm day−1 and four at 225 mm day−1. Half the CWs were planted with Cyperus papyrus and half with Echinochloa pyramidalis. Water samples were taken at the inlets and outlets and analyzed for TP, TDP, NH4-N, and TSS. Mass removal rates of the selected water quality parameters were compared during three periods designated the short rain (period 1), dry (period 2), and long rain (period 3) seasons. There was a significant linear relationship between the mass removal rate of TP, NH4-N, and TSS and the mass load, and season had a significant effect on the mass removal rate of TSS, NH4-N, and TDP. Mass loading rates for TDP were about 78% of those for TP, whereas TDP comprised 78–99% of TP mass outflow rates, indicating a release of dissolved P within the CWs. The only significant difference between the two macrophyte species was associated with mass removal of NH4-N, with more efficient removal in CWs planted with C. papyrus than those with E. pyramidalis. TP mass removal rates were 50–80% higher when a mean water loss for CWs 6–8 during periods 1 and 2 was assumed to represent evapotranspiration for all CWs in period 3 instead of pan evaporation data. This illustrated the importance of accurate estimations of evapotranspiration for pollutant mass removal rates in CWs in tropical climates.
|
|
| 2. |
- Drangert, Jan-Olof, 1944-, et al.
(author)
-
Generating Applicable Environmental Knowledge among Farmers : Experiences from Two Regions in Poland
- 2017
-
In: Agroecology and Sustainable Food Systems. - : Taylor & Francis. - 2168-3565 .- 2168-3573. ; 41:6, s. 671-690
-
Journal article (peer-reviewed)abstract
- Raising environmental awareness among farmers is the key to successfully reaching environmental goals. The present study assessed the knowledge development process and the raising of environmental awareness among 30 farmers from Poland exposed to four approaches aimed to reduce phosphorus (P) and nitrogen (N) losses to water. The farmers were interviewed with open-ended questions on-farm both before and after the project intervention. As hoped, the farmers attempted to adjust their farm practices to the European Union regulations, which are in some cases supported by subsidies. As a complement, the project offered tools for system-thinking based on farm data and support from agricultural advisors: a) a survey of plant-available P, potassium (K), magnesium (Mg), and soil pH, resulting in soil maps; b) assessment of nitrogen leaching risks from individual fields; c) compilation of a farm-gate balance. Farmers were positive to soil surveys and maps, but had limited understanding of the nutrient balance concept and calculations. They generally relied on their own experiences regarding fertilization rather than on calculated farm nutrient balances and leaching risks. Farmers’ understanding and willingness to adopt new approaches to improve nutrient efficiency and reduce negative environmental impacts are discussed.
|
|
| 3. |
|
|
| 4. |
- Tonderski, Karin, 1958-, et al.
(author)
-
BONUS MIRACLE ‐ Mediating integrated actions for sustainable ecosystem services in a changing climate
- 2018
-
Conference paper (other academic/artistic)abstract
- Water and nutrient governance in the Baltic Sea Region face several challenges. The future is highly uncertain due to climate change and on-going land-use changes, and different sectors works towards partly contradicting objectives, which makes it difficult to bring about integrated governance. In BONUS MIRACLE, a social learning process has been enacted to identify new configurations for water governance based on the hypothesis that more effective approaches to 'nutrient governance' need to bring on-board new constellations of actors with stakes in local issues that are interconnected with nutrient enrichment. A series of learning events between stakeholder groups and researchers in four case areas have been orchestrated. To support the process of reconciling stakeholder interests, researchers were asked to provide ´on-demand´ results regarding effects, cost-efficiency and benefits of suggested measures on water flow, nutrient transport (using the HYPE model) and other ecosystem services benefits under different climate change and land-use scenarios. Results were visualized in the MIRACLE Visualization Tool. Lessons learnt and results of policy analyses were used to discuss governance approaches on the BSR level that could support more integrated actions. An important project insight is that case level stakeholders, in general, are not interested in learning how different measures perform in reducing nutrient enrichment at a larger Baltic Sea basin level. Rather, they are interested in the impact measures have in terms of addressing multiple demands in the local settings. Regarding stakeholder positions, insights have emerged pertaining the important role position holders play in hindering or enabling change processes. In the ´pathways to change´, application of mineral fertilizers was one of the more cost-efficient measures suggested, along with creation of increased water retention, floodplains and wetlands. The latter also provide other ecosystem service benefits, and an approach was developed to interactively assess those, despite considerable knowledge gaps regarding effects and values. On the BSR level, the Visualization Tool provided useful learning support by visualizing E-HYPE model results regarding water flow and nutrient transport, as on this level the stakeholder´s system of interest is on governance innovations that address the nutrient issue. E-HYPE scenario modeling showed that while the mean water flow is expected to decrease in some southern BSR catchments, a substantial increase is predicted for most others. Similarly, the load of nitrogen may increase up to 25 % in some parts of the northern BSR, whereas a slight decrease is predicted for the south/southwestern parts. Governance innovations are needed that can accommodate those differences. However, current policies are insufficiently coordinated and integrated between sectors, due to imbalanced power relations and opposing agendas. This remains a constraint for the effectiveness of existing policy strategies, regulations and directives in addressing multiple ecosystem benefits. The involvement of local stakeholders needs to be strengthened and new models for cooperative and collective measures with intermediaries tested, to stimulate the use of local knowledge in improving the effectiveness and efficiency of management measures and reducing transaction costs. The synthesized BONUS MIRACLE results will be translated into a "Roadmap for improving water resource management in the Baltic Sea Region", with suggestions for adaptation of policies, institutional settings and governance arrangements.
|
|
| 5. |
- Weisner, Stefan, 1954-, et al.
(author)
-
Näringsavskiljning i anlagda våtmarker i jordbruket : Analys av mätresultat och effekter av landsbygdsprogrammet
- 2015
-
Reports (other academic/artistic)abstract
- I denna rapport sammanställs och analyseras tidigare mätningar av avskiljning av fosfor och kväve i anlagda våtmarker. Resultaten indikerar hur hög fosfor och kväveavskiljning som kan uppnås i anlagda våtmarker i jordbrukslandskap i Sverige. Resultaten har även använts för att ta fram nya modeller för beräkning av avskiljning av fosfor och kväve i våtmarker där mätningar inte gjorts. Slutligen har dessa modeller använts för att beräkna hur hög avskiljning som kommer att uppnås i våtmarker som beviljats stöd inom landsbygdsprogrammet åren 2007– 2013 och hur mycket transporten av kväve och fosfor till havet kommer att minskas genom att dessa våtmarker har anlagts.De nya mätresultaten visar att fosforavskiljning underskattats i tidigare mätningar och i modeller som använts i tidigare utvärderingar. I enskilda väl utformade och placerade våtmarker kan 100 kilo fosfor och 1 000 kilo kväve per hektar våtmarksyta och år avskiljas. De nya resultaten indikerar även att man i framtida program för anläggning av våtmarker i jordbrukslandskapet bör kunna uppnå en genomsnittlig fosfor och kväveavskiljning på 50 respektive 500 kilo per hektar våtmarksyta och år, förutsatt att näringsavskiljning kan prioriteras vid placering och utformning av våtmarker. Kostnaden för avskiljning uppskattas till cirka 100 kronor per kilo fosfor och cirka 10 kronor per kilo kväve för sådana våtmarker om 50 procent av kostna derna fördelas till andra ekosystemtjänster och biologisk mångfald.Modellberäkningar på ett urval av våtmarker inom landsbygdsprogrammet som skalats upp till de 5 261 hektar som beviljats stöd under 2007–2013 visar att transporten av fosfor och kväve till lokala vattendrag kommer att minskas med cirka 25 ton fosfor per år och cirka 200 ton kväve per år. Det innebär att minsk ningen av transporten till havet som åstadkoms genom dessa våtmarker blir cirka 18 ton fosfor per år och cirka 170 ton kväve per år, vilket motsvarar 1,9 respektive 0,5 procent av transporten till havet från jordbruksmark.Anläggningen av våtmarker inom landsbygdsprogrammet har således haft betydelse för att minska fosfor och kvävetransporter såväl till lokala vattendrag som till havet. En jämförelse av genomsnittlig avskiljning per hektar våtmarksyta mellan landsbygdsprogrammet och den avskiljning som uppnås i individuella våtmarker visar emellertid att effektiviteten skulle kunna höjas betydligt i framtiden genom en bättre placering och utformning av våtmarker i landskapet.
|
|
| 6. |
|
|
| 7. |
- Akram, Usman, 1984-
(author)
-
Closing nutrient cycles
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- Adequate and balanced crop nutrition – with nitrogen (N), phosphorus (P), and potassium (K) – is vital for sustainable crop production. Inadequate and imbalanced crop nutrition contributes to the crop yield gaps – a difference in actual and potential crop yield. Yield gap is one of the many causes of insufficient food production, thus aggravating hunger and malnourishment across the globe. On the other hand, an oversupply of nutrients is highly unsustainable, in terms of both resource conservation and global environmental health. A decreasing excreta recycling in crop production is one of the many reasons for nutrient imbalances in agriculture. Previous studies show that increasing agricultural specialization leads to spatial separation of crop and animal production. Increasing distance between excreta production and crop needs is one of the leading factors that cause reduced excreta recycling. Studies focusing on excreta recycling show that a substantial barrier to a more efficient excreta nutrient reuse is the expensive transportation of bulky volumes of excreta over long distances. In order to overcome that barrier, more detailed spatial estimates of distances between excreta production and crop nutrient needs, and the associated costs for complete excreta transport in an entire country are needed. Hence, the overall aim of this thesis was to quantify the amount of nutrients in the excreta resources compared to the crop nutrient needs at multiple scales (global, national, subnational, and local), and to analyze the need for excreta transports, total distances and costs, to meet the crop nutrient needs in a country.On the global scale, annual (2000-2016) excreta supply (livestock and human) could provide at least 48% of N, 57% of P, and 81% of K crop needs. Although excreta supply was not enough to cover the annual crop nutrient needs at the global scale, at least 29 countries for N, 41 for P, and 71 for K had an excreta nutrient surplus. When including the annual use of synthetic fertilizers, at least 42 additional countries had a N surplus, with the equivalent figures for P being 17 countries, whereas 8 additional countries attained a K surplus. At the same time, when accounting for the use of synthetic fertilizers, each year, at least 57 countries had an N deficit, 70 a P deficit, and 51 countries a K deficit, in total equivalent to 14% of global N and 16% of each P and K crop needs. The total surplus in other countries during the period was always higher than the deficit in the countries with net nutrient deficits, except for P for some years. Unfortunately, both the deficits of the deficit countries and surpluses of the surplus countries were increasing substantially during the 17 years. Such global divergence in nutrient deficits and surpluses have clear implications for global food security and environmental health.A district-scale investigation of Pakistan showed that the country had a national deficit of 0.62 million tons of P and 0.59 million tons of K, but an oversupply of N. The spatial separation was not significant at this resolution; only 6% of the excreta N supply needed to be transported between districts. Recycling all excreta, within and between districts, could cut the use of synthetic N to 43% of its current use and eliminate the need for synthetic K, but there would be an additional need of 0.28 million tons of synthetic P to meet the crop nutrient needs in the entire country. The need for synthetic fertilizers to supplement the recycled excreta nutrients would cost USD 2.77 billion. However, it might not be prohibitively expensive to correct for P deficiencies because of the savings on the costs of synthetic N, and K. Excreta recycling could promote balanced crop nutrition at the national scale in Pakistan, which in turn could eliminate the nutrient-related crop yield gaps in the country.The municipal-scale investigation using Swedish data showed that the country had a national oversupply of 110,000 tons of N, 6,000 tons of P, and 76,000 tons of K. Excreta could provide up to 75% of N and 81% of P, and more than 100% of the K crop needs in the country. The spatial separation was pronounced at the municipal scale in the country. Just 40% of the municipalities produced over 50% of the excreta N and P. Nutrient balance calculations showed that excreta recycling within municipalities could provide 63% of the P crop needs. Another 18% of the P crop needs must be transported from surplus municipalities to deficit municipalities. Nationally, an optimized reallocation of surplus excreta P towards the P deficit municipalities would cost USD 192 million for a total of 24,079 km truck transports. The cost was 3.7 times more than the total NPK fertilizer value transported, and that met the crop nutrient needs. It was concluded that Sweden could potentially reduce its dependence on synthetic fertilizers, but to cover the costs of an improved excreta reuse would require valuing the additional benefits of recycling.An investigation was also done to understand the effect of the input data resolution on the results (transport needs and distances) from a model to optimize excreta redistribution. The results showed that the need for excreta transports, distances, and spatial patterns of the excreta transports changed. Increasing resolution of the spatial data, from political boundaries in Sweden and Pakistan to 0.083 decimal grids (approximately 10 km by 10 km at the equator), showed that transport needs for excreta-N increased by 12% in Pakistan, and the transport needs for excreta-P increased by 14% in Sweden. The effect of the increased resolution on transport analysis showed inconsistency in terms of the excreta total nutrient transportation distance; the average distance decreased by 67% (to 44 km) in Pakistan but increased by 1 km in Sweden. A further increase in the data resolution to 5 km by 5 km grids for Sweden showed that the average transportation distance decreased by 9 km. In both countries, increasing input data resolution resulted in a more favorable cost to fertilizer value ratios. In Pakistan, the cost of transport was only 13% of the NPK fertilizer value transported at a higher resolution. In Sweden, the costs decreased from 3.7 (at the political resolution) to slightly higher than three times of the fertilizer value transported in excreta at the higher data resolution.This Ph.D. thesis shows that we could potentially reduce the total use of synthetic fertilizers in the world and still reduce the yield gaps if we can create a more efficient recycling of nutrients both within and between countries, and a more demand adapted use of synthetic fertilizers.
|
|
| 8. |
- Andersson, J., et al.
(author)
-
Free water surface wetlands for wastewater treatment in Sweden : Nitrogen and phosphorus removal
- 2005
-
In: Water Science and Technology. - 0273-1223 .- 1996-9732. ; 51:9, s. 39-46
-
Journal article (peer-reviewed)abstract
- In South Sweden, free water surface wetlands have been built to treat wastewater from municipal wastewater treatment plants. Commonly, nitrogen removal has been the prime aim, though a significant removal of tot-P and BOD7 has been observed. In this study, performance data for 3-8 years from four large (20-28 ha) FWS wetlands have been evaluated. Two of them receive effluent from WWTP with only mechanical and chemical treatment. At the other two, the wastewater has also been treated biologically resulting in lower concentrations of BOD7 and NH4+-N. The wetlands performed satisfactorily and removed 0.7-1.5 ton N ha-1 yr-1 as an average for the time period investigated, with loads between 1.7 and 6.3 ton N ha-1 yr-1. Treatment capacity depended on the pre-treatment of the water, as reflected in the k20-values for N removal (first order area based mode). In the wetlands with no biological pre-treatment, the k20-values were 0.61 and 1.1 m month-1, whereas for the other two they were 1.7 and 2.5 m month-1. P removal varied between 10 and 41 kg ha-1 yr-1, and was related to differences in loads, P speciation and to the internal cycling of P in the wetlands. © IWA Publishing 2005.
|
|
| 9. |
- Bojcevska, Hristina, 1977-, et al.
(author)
-
Impact of loads, season, and plant species on the performance of a tropical constructed wetland polishing effluent from sugar factory stabilization ponds
- 2007
-
In: Ecological Engineering. - : Elsevier BV. - 0925-8574 .- 1872-6992. ; 29:1, s. 66-76
-
Journal article (peer-reviewed)abstract
- The effects of wastewater loading rates and two macrophyte species on treatment of sugar factory stabilization pond effluent were investigated in a pilot-scale free water surface constructed wetland (FWS CW) system in western Kenya. For 12 months, four CWs were operated at a hydraulic loading rate of 75 mm day−1 and four at 225 mm day−1. Half the CWs were planted with Cyperus papyrus and half with Echinochloa pyramidalis. Water samples were taken at the inlets and outlets and analyzed for TP, TDP, NH4-N, and TSS. Mass removal rates of the selected water quality parameters were compared during three periods designated the short rain (period 1), dry (period 2), and long rain (period 3) seasons. There was a significant linear relationship between the mass removal rate of TP, NH4-N, and TSS and the mass load, and season had a significant effect on the mass removal rate of TSS, NH4-N, and TDP. Mass loading rates for TDP were about 78% of those for TP, whereas TDP comprised 78–99% of TP mass outflow rates, indicating a release of dissolved P within the CWs. The only significant difference between the two macrophyte species was associated with mass removal of NH4-N, with more efficient removal in CWs planted with C. papyrus than those with E. pyramidalis. TP mass removal rates were 50–80% higher when a mean water loss for CWs 6–8 during periods 1 and 2 was assumed to represent evapotranspiration for all CWs in period 3 instead of pan evaporation data. This illustrated the importance of accurate estimations of evapotranspiration for pollutant mass removal rates in CWs in tropical climates.
|
|
| 10. |
|
|
| 11. |
- Carolus, Johannes Friedrich, et al.
(author)
-
Nutrient mitigation under the impact of climate and land-use changes : A hydro-economic approach to participatory catchment management
- 2020
-
In: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 271
-
Journal article (peer-reviewed)abstract
- Excessive nutrient loadings into rivers are a well-known ecological problem. Implemented mitigation measures should ideally be cost-effective, but perfectly ranking alternative nutrient mitigation measures according to cost-effectiveness is a difficult methodological challenge. Furthermore, a particularly practical challenge is that cost-effective measures are not necessarily favoured by local stakeholders, and this may impede their successful implementation in practice. The objective of this study was to evaluate the cost-effectiveness of mitigation measures using a methodology that includes a participatory process and social learning to ensure their successful implementation. By combining cost data, hydrological modelling and a bottom-up approach for three different European catchment areas (the Latvian Berze, the Swedish Helge and the German Selke rivers), the cost-effectiveness of 16 nutrient mitigation measures were analysed under current conditions as well as under selected scenarios for future climate and land-use changes. Fertiliser reduction, wetlands, contour ploughing and municipal wastewater treatment plants are the measures that remove nutrients with the highest cost-effectiveness in the respective case study context. However, the results suggest that the cost-effectiveness of measures not only depends on their design, specific location and the conditions of the surrounding area, but is also affected by the future changes the area may be exposed to. Climate and land-use changes do not only affect the cost-effectiveness of measures, but also shape the overall nutrient loads and potential target levels in a catchment.
|
|
| 12. |
- Carraro, Giacomo, et al.
(author)
-
Solid-liquid separation of digestate from biogas plants: A systematic review of the techniques’ performance
- 2024
-
In: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 356
-
Research review (peer-reviewed)abstract
- Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by advanced treatments of the fractions. The knowledge about the performance of the separators and the quality of the fractions is scattered because of many available techniques and large variability in digestate characteristics. We performed a systematic review and found 175 observations of full-scale solid-liquid separation of digestate. We identified 4 separator groups, 4 digestate classes based on substrate, and distinguished whether chemical conditioners were used. We confirmed the hypothesis that the dominant substrate can affect the efficiency of the digestate separation. Furthermore, the results showed that centrifuges separated significantly more dry matter and total P than screw presses. Use of chemical conditioners in combination with a centrifuge lowered the dry matter concentration in the liquid fraction by 30%. Screw presses consumed 4.5 times less energy than centrifuges and delivered 3.3 tonne ammonium N in the liquid fraction and 0.3 tonne total P in the solid fraction using 1 MWh. The results can provide data for systems analyses of biogas solutions and can support practitioners when choosing among full-scale separator techniques depending on the digestate type. In a broader perspective, this work contributes to the continuous improvement of biogas plants operations and to their role as nutrients recovery sites.
|
|
| 13. |
|
|
| 14. |
- Drangert, Jan-Olof, 1944-, et al.
(author)
-
Extending the European Union Waste Hierarchy to Guide Nutrient-Effective Urban Sanitation toward Global Food Security : Opportunities for Phosphorus Recovery
- 2018
-
In: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; 2, s. 1-13
-
Journal article (peer-reviewed)abstract
- With growing urbanization cities become hotspots for nutrients. Food items are imported, and food residues, including excreta and not-eaten food, are often exported to landfill sites and water bodies. However, urban sanitation systems can be designed to achieve a high degree of nutrient recovery and food security while counteracting current nutrient resources depletion, environmental degradation, and wasteful energy use. This article illustrates how an extended solid waste hierarchy also including human excreta and wastewater can guide actions to save and recover phosphorus (P) by the three sectors: food industry, households, and waste utilities. P use in diets and agricultural production is not part of the analysis, despite the potential to save P. Novel systems thinking and material flow analysis show that waste prevention can replace over 40% of mined P presently used for making fertilizers. Reuse and recycling of P in excreta and food waste can replace another 15–30%, depending on P efficiency from mine to plate. Keeping excreta separated from other wastewater facilitates such measure. Incineration and land filling are deemed the least appropriate measures since mainly P is recovered in the ashes. The European Union (EU) waste management policy is analyzed for real barriers and opportunities for this approach. The EU Parliament policy guidelines were watered down in the EU Commission’s Directives, and today most biowastes are still being landfilled or incinerated instead of recovered. An anticipated overcapacity of incineration plants in Europe threatens to attract all combustible materials and therefore, irrevocably, reduce nutrient recovery. On the other hand, reduced generation and enhanced recovery can delay exhaustion of P resources by several centuries and simultaneously reduce environmental degradation.
|
|
| 15. |
- Feizaghaii, Roozbeh, 1975-, et al.
(author)
-
Systems analysis of digestate primary processing techniques
- 2022
-
In: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 150, s. 352-363
-
Journal article (peer-reviewed)abstract
- In this paper, we performed technology assessment and systems analysis of primary digestate processing techniques to provide a comprehensive analysis of their environmental and cost performance. We compiled more than 100 observations from large-scale biogas plants and considered digestate based on manure, crops and agro-wastes, and food waste under the geographical contexts of Sweden and Belgium. Centrifuge, screw press, and rotary drum were identified as suitable primary processing techniques. We analyzed the climate impact, energy use, and operational cost of digestate management under these scenarios: no processing, partial processing (solid-liquid separation) and full processing (solid-liquid separation followed by ammonia stripping). As expected, the suitable digestate processing varied with the context, transport was often the most critical cost factor, and emissions from storage reduced the climate savings from the use of biofertilizers. However, treating liquid fraction became a main contributor to cost and climate impact under the Belgian conditions. Consequently, the possibility for local application of liquid fraction as biofertilizer could prevent costs and impacts associated with its further treatment. The main novelty of this work is in its integrative and comprehensive approach toward the choices and impacts of primary processing of digestate. We tried to bridge many individual case studies, drew from experiences of biogas plants in different geographical contexts, assessed suitable processing techniques for different digestate types, and analyzed the environmental impacts and cost of digestate management from a life cycle perspective. We believe that such integrated approaches would help decision-making for increased sustainability of the biogas sector.
|
|
| 16. |
- Geranmayeh, Pia, et al.
(author)
-
Phosphorus Retention in a Newly Constructed Wetland Receiving Agricultural Tile Drainage Water
- 2013
-
In: Journal of Environmental Quality. - : Wiley. - 0047-2425 .- 1537-2537. ; 42, s. 596-605
-
Journal article (peer-reviewed)abstract
- One measure used in Sweden to mitigate eutrophication of waters is the construction of small wetlands (free water surface wetland for phosphorus retention [P wetlands]) to trap particulate phosphorus (PP) transported in ditches and streams. This study evaluated P retention dynamics in a newly constructed P wetland serving a 26-ha agricultural catchment with clay soil. Flow-proportional composite water samples were collected at the wetland inlet and outlet over 2 yr (2010-2011) and analyzed for total P (TP), dissolved P (DP), particulate P (PP), and total suspended solids (TSS). Both winters had unusually long periods of snow accumulation, and additional time-proportional water samples were frequently collected during snowmelt. Inflow TP and DP concentrations varied greatly (0.02-1.09 mg L-1) during the sampling period. During snowmelt in 2010, there was a daily oscillation in P concentration and water flow in line with air temperature variations. Outflow P concentrations were generally lower than inflow concentrations, with net P losses observed only in August and December 2010. On an annual basis, the wetland acted as a net P sink, with mean specific retention of 69 kg TP, 17 kg DP, and 30 t TSS ha(-1) yr(-1), corresponding to a reduction in losses of 0.22 kg TP ha(-1) yr(-1) from the agricultural catchment. Relative retention was high (36% TP, 9% DP, and 36% TSS), indicating that small constructed wetlands (0.3% of catchment area) can substantially reduce P loads from agricultural clay soils with moderately undulating topography.
|
|
| 17. |
- Grönlund, Erik, 1964-, et al.
(author)
-
Emergy Assessment of a Wastewater Treatment Pond System in the Lake Victoria Basin
- 2017
-
In: Journal of Environmental Accounting and Management. - Carbon, United States : L & H Scientific Publishing, LLC. - 2325-6192 .- 2325-6206. ; 5:1, s. 11-26
-
Journal article (peer-reviewed)abstract
- As part of efforts to reduce the eutrophying load to Lake Victoria, a wastewater treatment system at one of the sugar factories in Kenya was evaluated with the ecosystem ecology method emergy accounting. As a comparison a traditional cost analysis was also performed. The analysis included the local and imported ecosystem services. After preliminary treatment the effluent was discharged into a series of 12 stabilisation ponds. The removal of COD and TSS was high, whereas phosphorus concentrations were reduced by less than 20 %. The monetary costs were dominated by operation and management cost, some of which could probably be reduced by more effective management. The local ecosystem services in emergy terms contributed only 1% (or 1,000 Em$) to the treatment system. Imported ecosystem services in purchased lime contributed more to the treatment system, 22% (or 24,600 Em$). Since the land costs in the area were low, land demanding treatment methods using free local ecosystem services, could be cost effective choices for wastewater management. Ecosystem ecology methods as emergy accountings can guide these choices by revealing the additional contribution of free ecosystem services. Emergy accountings seem to need further clarification regarding differences in micro-/macroeconomic views.
|
|
| 18. |
- Hasler, Berit, et al.
(author)
-
Sustainable ecosystem governance under changing climate and land use : An introduction
- 2019
-
In: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; 48, s. 1235-1239
-
Journal article (other academic/artistic)abstract
- Combatting eutrophication is currently a major challenge for policy makers in the Baltic Sea region, and it is likely to remain so in the decades to come. Although total nutrient loads to the Baltic Sea have recently declined, the gap between current loadings and those required to ensure the desired status is still substantial (Reusch et al. 2018). This Special Issue is dedicated to research that helps inform how the eutrophication challenge might best be addressed by improving our understanding of technological constraints, societal drivers of change, land uses, environmental policies, and innovative governance with stakeholder involvement. These issues are important for the current generation and those to come and are issues we must address in order to succeed in reducing nutrient loads to the desired levels to gradually achieve the desired good environmental status of the Baltic Sea. Currently, we witness a new era of water policies across the entire Baltic Sea region. Our changing climate is impacting on precipitation and runoff, and is also the reason why new EU climate policies seek to tie carbon sinks more visibly to carbon sources. Both these aspects have repercussions for water policies. Thus, solving eutrophication challenges requires sharpening of existing policies and instruments, as well as creating new insights and governance approaches with broad stakeholder involvement in a changing environment. In order to design coherent water and climate policies, and target and implement those policies more efficiently, policy makers need to combine new insights regarding the inhabitants in the region, the catchments, and the Baltic Sea itself. Such insights can be expected from soil scientists, agronomists, hydrogeologists, marine ecologists, economists, and social and policy scientists. What is needed is on the one hand effectively targeted governance at appropriate spatial and temporal scales, adapted to differing interests and motivations of citizens living around the Baltic Sea, and on the other hand fine tuning and co-designing of policies at local, national, Baltic Sea regional and EU level. This Special Issue brings together recent research from four BONUS-funded projects—BONUS BALTICAPP, BONUS GO4BALTIC, BONUS MIRACLE and BONUS SOILS2SEA—that comprised part of the ‘Viable Ecosystem’ and ‘Sustainable Ecosystem Services’ BONUS research programmes. The projects addressed these common concerns through somewhat different, but inter-related, themes. Key messages emphasized and discussed in the research papers of this Special Issue are summarized under four interlinked themes: Scenarios for the future, Policies and ecosystem services in water governance, Novel approaches for managing nutrients, and Advanced modelling from field level to the entire Baltic Sea region.
|
|
| 19. |
- Land, Magnus, et al.
(author)
-
How effective are created or restored freshwater wetlands for nitrogen and phosphorus removal? A systematic review protocol
- 2013
-
In: Environmental Evidence. - : BioMed Central. - 2047-2382. ; 2:16
-
Journal article (peer-reviewed)abstract
- Background: Eutrophication of aquatic environments is a major environmental problem in large parts of the world.In Europe, EU legislation (the Water Framework Directive and the Marine Strategy Framework Directive),international conventions (OSPAR, HELCOM) and national environmental objectives emphasize the need to reducethe input of plant nutrients to freshwater and marine environments. A widely used method to achieve this is to letwater pass through a constructed or restored wetland (CW). However, the large variation in measured nutrientremoval rates in such wetlands calls for a systematic review. The objective of this review is to quantify nitrogen andphosphorus removal rates in constructed or restored wetlands and relate them to wetland characteristics, loading characteristics, and climate factors. Wetlands are created to treat water from a number of different sources. Sources that will be considered in this review include agricultural runoff and urban storm water run-off, as well as aquaculture wastewater and outlets from domestic wastewater treatment plants, with particular attention to thesituation in Sweden. Although the performance of wetlands in temperate and boreal regions is most relevant tothe Swedish stakeholders a wider range of climatic conditions will be considered in order to make a thorough evaluation of climatic factors.Methods: Searches for primary studies will be performed in electronic databases as well as on the internet. Oneauthor will perform the screening of all retrieved articles at the title and abstract level. To check that the screeningis consistent and complies with the agreed inclusion/exclusion criteria, subsets of 100 articles will be screened by the other authors. When screening at full-text level the articles will be evenly distributed among the authors. Kappatests will be used to evaluate screening consistency. Data synthesis will be based on meta-regression. The nutrient removal rates will be taken as response variables and the effect modifiers will be used as explanatory variables. More specifically, the meta-regression will be performed using generalized additive models that can handle nonlinear relationships and major interaction effects. Furthermore, subgroup analyses will be undertaken to elucidate statistical relationships that are specific to particular types of wetlands.
|
|
| 20. |
- Larsson, Madeleine, 1984-, et al.
(author)
-
Towards a more circular biobased economy and nutrient use on Gotland : finding suitable locations for biogas plants
- 2023
-
Reports (other academic/artistic)abstract
- In this study we have investigated the role of biogas solutions to support increased resource efficiency on the island Gotland, including recovery and redistribution of nitrogen (N) and phosphorus (P) within the agricultural sector. First, we analyzed the potential for expanding energy and nutrient recovery from organic residues using biogas solutions. Our findings suggest that the biogas production could expand to 165 GWh, from the current 36 GWh (2020), with manure accounting for a potential 110 GWh biogas annually if all were digested. Comparing the nutrients contained in organic feedstock with the crop nutrient demand on Gotland showed that for N the demand is 2.4 times higher than the supply. In contrast, the calculations showed a 137 tonnes P surplus, with distinct excess areas in the center and southern part of the island.We then compared scenarios with different numbers (3 - 15) of biogas plants with respect to efficient nutrient redistribution and transport costs. Spatial constraints for new plants, e.g. need for roads with a certain capacity and permit issues, were accounted for by adding local information to a national data set. We identified 104 potential locations (1 km$^2$ grid cells) and used an optimization model to identify the most suitable locations for minimized transport costs. Optimal (meeting the crop demand with no excess) redistribution of all nutrients contained in the feedstock, as raw digestate from biogas plants, would result in an export of 127 tonnes of P from the island. The model results indicated that if all potential feedstock would be digested in three additional biogas plants and nutrients redistributed for optimal reuse, the total transport cost would be 2.6 million SEK annually, excluding the costs for nutrient export from the island (3.7 million SEK). If instead 10 or 15 smaller plants would be built, the transport cost would drop to 1.8 million SEK, with the same amount of P being exported. Comparing the scenarios with different number of biogas plants (3 - 15), showed that some locations are more suitable than others in terms of distance to feedstock andto fields with fertilizer demands. Finally, a preliminary analysis of the amount of crop residues indicated that this type of feedstock could add a substantial amount of biogas production, but more extensive analyses are needed to assess the feasibility to realize part of that potential.
|
|
| 21. |
|
|
| 22. |
- Lind, Linus, et al.
(author)
-
Nitrate removal capacity and nitrous oxide production in soil profiles of nitrogen loaded riparian wetlands inferred by laboratory microcosms
- 2013
-
In: Soil Biology and Biochemistry. - : Elsevier. - 0038-0717 .- 1879-3428. ; 60, s. 156-164
-
Journal article (peer-reviewed)abstract
- Riparian wetlands located in agricultural catchments may often receive a high nitrate (NO3−) load because of the leaching of nutrients derived from upland farming activities. Nitrate can be removed in wetland soils by denitrification which is the reduction of NO3− to the gaseous forms nitrous oxide (N2O) and dinitrogen (N2). However, the release of N2O is detrimental to the environment because N2O is a potent greenhouse gas. Therefore, this study aimed at investigating the factors controlling the production of N2O and at evaluating the risk for N2O emissions from riparian wetland soils. In a laboratory setup, we simulated an upward flow of NO3− enriched groundwater through intact soil cores collected from four wetlands with contrasting soil characteristics. The results showed a rapid reduction of the NO3− fluxes, supporting the effectiveness of wetlands for removal of N. However, during the reduction of NO3− transient accumulation of N2O was observed, but the N2O concentration decreased with declining NO3− availability. In this study, the NO3− load was revealed as the only significant factor controlling both NO3− reduction and N2O production. Our results confirm the capacity of wetlands to remove large amounts of N, but it also showed that substantial emission of N2O might occur if the reduction of NO3− is not complete, a matter to be considered when diverting N rich waters toward wetlands.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Metson, Genevieve S., 1988-, et al.
(author)
-
Optimizing transport to maximize nutrient recycling and green energy recovery
- 2020
-
In: Resources, Conservation & Recycling: X. - : Elsevier. - 2590-289X. ; 9-10
-
Journal article (peer-reviewed)abstract
- A circular biobased economy must be able to sustainably manage multiple resources simultaneously. Nutrient (nitrogen, phosphorus, and potassium) recycling and renewable energy production (biogas) can be compatible practices but require substantial transport of heavy organic waste. We combine a spatial optimization model and Life Cycle Assessment (LCA) to explore how Sweden could maximize its use of excreta resources. We use 10×10 km2 resolution data on the location of animal and human excreta and crop demand and model both optimal biogas plant locations and transport of nutrients to and from these plants. Each type of biogas plant (given 4 realistic mixes of excreta) is then evaluated for global warming potential, primary energy use and financial resource costs. Moving excreta through biogas plants, as opposed to simply reapplying on fields, to meet crop nutrient demands comes at a similar cost but the climate and primary energy savings are substantial. As much as 91% of phosphorus and 44% of nitrogen crop demand could be met via optimally transported excreta and the country would avoid about 1 450 kt of CO2-eq, save 3.6 TWh (13 000 tera-joules) of primary energy, and save 90 million euros per year. Substituting mineral fertilizers with recycled nutrients results in savings across all indicators, but the added energy and avoided greenhouse gas emissions associated with biogas production make a large difference in the attractiveness of nutrient recycling. Although the numeric values are theoretical, our results indicate that carefully coordinated and supported biogas production could help maximize multi-resource benefits.
|
|
| 26. |
|
|
| 27. |
- Skvortsova, Polina, et al.
(author)
-
Synergetic Effect of Digestate Dissolved Organic Matter and Phosphogypsum Properties on Heavy Metals Immobilization in Soils
- 2024
-
In: Journal of Engineering Sciences. - Ukraine : Sumy State University. - 2312-2498 .- 2414-9381. ; 11:1, s. H9-H20
-
Journal article (peer-reviewed)abstract
- The main idea was to justify the natural, technological, and ecological aspects of digestate-based composite for heavy metals (HMs) binding in soil due to organic matter content and mineral additives’ biosorption properties. The study aimed to determine the potential of a composite made from digestate and phosphogypsum for remediation of HMs polluted soils and the role of dissolved organic matter (DOM) in binding HMs. Methods used included a literature review to identify the mechanisms for HM binding to digestate DOM, a laboratory setup for producing a digestate-based composite with digestate (from manure or sewage sludge) mixed with phosphogypsum, and an analysis of digestate fluorescence properties. Results show that a composite based on digestate from manure as feedstock had a higher fluorescence complexity index than a composite with sewage sludge digestate (2.2 and 1.71, respectively). However, the DOM stability in the sewage sludge digestate composite was higher than reported in the literature, probably due to the mineral composition of phosphogypsum, which resulted in a high HMs sorption capacity and its positive effect on soil microbial activity. Based on the theoretical substantiation of DOM content and its binding properties, manure was the most effective feedstock type out of the two tested if digestate was used for HM remediation. Using a digestate-based composite with phosphogypsum can potentially reduce the ecological risk levels imposed by HM-contaminated soils from considerably too low.
|
|
| 28. |
|
|
| 29. |
- Sundblad-Tonderski, Karin, 1958-
(author)
-
Recycling of wastewater nutrients in a wetland filter
- 1988
-
Doctoral thesis (other academic/artistic)abstract
- This thesis demonstrates the possibility of using wastewater nutrients for plant biomass production and concomitantly achieving year-round wastewater treatment. As part of a joint research project, the emphasis in this thesis is on nutrient recycling capacity relative to treatment efficiency.An artificial wetland system was studied in experimental field lysimeters. Wastewater was infiltrated into soil planted with reed sweetgrass (Glyceria maxima). In natural stands of this grass, harvesting two or three times per year had a negative impact on biomass yields. This was attributed to a reduced amount of carbohydrates stored in the rhizomes, resulting in the formation of thinner shoots in harvested stands. In contrast to this, high biomass yields were obtained with two harvests per year in the wetland filter.Crop removal of nitrogen and phosphorus amounted to a maximum of 55% and 28% of the amount applied during a growing season. Year-round wastewater application would decrease the relative removal because no plant uptake occurrs during the winter months. However, applied nutrients are also transferred to the soil, thus contributing to the nutrient recycling capacity of the system. This may determine the longevity of a wet! and filter as a method of wastewater treatment, since the soil is gradually saturated with phosphorus. Another factor of importance for the long-term limitations is the observed decrease in soil permeability.Treatment efficiency of phosphorus and BOD7 met the required limits for wastewater emissions in Sweden. An average 60% removal of nitrogen was achieved, which is significantly more than in a conventional tertiary treatment plant. The costs for reaching this treatment level were estimated to be lower for a wet land filter than for the existing treatment systems for urban areas up to 1000 inhabitants. The feasibility for this conceptual change of better resource management with regard to present Swedish wastewater treatment strategy is discussed.
|
|
| 30. |
- Svedin, Christer, et al.
(author)
-
Cold Season Nitrogen Removal in a High Loaded Free Water Surface Wetland with Emergent Vegetation
- 2008
-
In: WASTEWATER TREATMENT, PLANT DYNAMICS AND MANAGEMENT IN CONSTRUCTED AND NATURAL WETLANDS. - dordrecht : Springer Netherlands. - 9781402082344 ; , s. 223-236
-
Book chapter (peer-reviewed)abstract
- The aim of this study was to quantify nitrogen removal in high loaded free water surface wetlands dominated by emergent vegetation. It was undertaken in two subsystems of the full-scale wetland Alhagen in Nynäshamn, Sweden. Time proportional samples were taken at the inlets and outlets for 2 weeks in September and November 2005, respectively, and the water flow was monitored. The samples were analysed for ammonium-N (NH4×-N), nitrate-N (NO3–-N), nitrite-N (NO2–-N) and total-N, and the mass nitrogen removal was calculated. Sediment cores were randomly collected to measure potential denitrification, and the result was related to the actual mass nitrogen removal. Zero total-N removal could be detected in the subsystem with 6 hours hydraulic retention time (HRT). In the one with 3–4 days HRT, the total-N removal rates were 0.6 g N m–2 day–1 in September and 0.2 g N m–2 day–1 in November. The potential denitrification rate was 8 times higher than the observed removal in September and 48 times higher in November. This deviation was likely related both to relatively high oxygen levels and to the amount of available organic carbon.
|
|
| 31. |
|
|
| 32. |
|
|
| 33. |
- Van Cleemput, O, et al.
(author)
-
Denitrification in Wetlands
- 2007. - 1
-
In: Biology of the nitrogen cycle. - Amsterdam : Elsevier. - 9780444531087 ; , s. 359-367
-
Book chapter (other academic/artistic)abstract
- All organisms require nitrogen to live and grow. The movement of nitrogen between the atmosphere, biosphere, and geosphere in different forms is described by the nitrogen cycle. This book is an activity of the COST 856 Action on Denitrification. It covers all aspects of the N-cycle: chemistry, biology (enzymology, molecular biology), physics, applied aspects (greenhouse effect, N-pollution problems, practices in farming, in waste-water treatment, and more). In this book, leading editors offer the latest research available on dentrification (reduction of nitrates or nitrites commonly by bacteria- as in soil). * Provides details on denitrification and its general role in the environment* Offers latest research in N-Cycle and its reactions* Discusses impacts on various environments: agriculture, wetlands, plants, waste-water treatment and more* The only book available in the field since the last 20 years* Contains 27 chapters written by internationally highly recognized experts in the field* Covers all modern aspects, emphasizes molecular biology and ecology* Written in an easily understandable way
|
|
| 34. |
- van de Vlasakker, Paulien C. H., et al.
(author)
-
A Review of Nutrient Losses to Waters From Soil- and Ground-Based Urban Agriculture—More Nutrient Balances Than Measurements
- 2022
-
In: Frontiers in Sustainable Food Systems. - Lausanne, Switzerland : Frontiers Media S.A.. - 2571-581X. ; 6
-
Journal article (peer-reviewed)abstract
- Urban agriculture has a high potential to contribute to local circular economies, for instance by using nitrogen, phosphorus, and potassium in city organic waste streams as fertilizer inputs. However, inefficient use of waste-derived fertilizers could contribute to local water quality impairment related to nitrogen and phosphorus losses. Organic waste derived fertilizers are particularly challenging from a nutrient stoichiometry perspective, making over- and under-application of a particular nutrient likely. Where, and under what conditions, urban agriculture acts as a net positive for a circular nutrient economy vs. a nutrient water quality risk remains unclear. Here we review empirical peer-reviewed studies (2000–2021) on soil- and ground-based urban agriculture with a stated concern for nutrient losses to water. Of the 20 publications retained and reviewed (out of 241 screened), only seven measured losses to waters. There were four experimental studies, of which three measured nutrient leachate losses under different garden management practices. Of the 16 studies done in real-world conditions, only four quantified losses to water as leachate; average losses spanned 0.005 to 6.5 kg ha−1 for phosphorus, and 0.05 to 140 kg ha−1 for nitrogen. 13 of the 16 non-experimental studies provided data on nutrient inputs and harvested crop outputs, which could be used to calculate garden nutrient balances—an indicator of nutrient use efficiency. Although the value ranges were large, most studied gardens showed nutrient surpluses (inputs > crop harvest) for nitrogen and phosphorus (but not potassium); these surpluses were identified as a risk for losses to water. Contextual factors such as different access to fertilizers and knowledge, along with regulations and environmental factors can help explain the wide range of balance values and nutrient losses observed. Although a large surplus of inputs was often linked to increased leachate losses, it was not always the case in the limited number of studies we identified. Our review suggests that more field studies that measure losses to waters, and document contextual factors, are needed to determine how urban agriculture may contribute to a sustainable circular economy for all three nutrients without nutrient-related water quality impairment.
|
|
| 35. |
- Vymazal, J, et al.
(author)
-
Constructed wetlands for wastewater treatment
- 2006
-
In: Wetlands and Natural Resource Management. Ecological Studies. - Berlin : Springer Verlag. - 3540331867 ; , s. 69-96
-
Book chapter (other academic/artistic)abstract
- Together with its companion, Volume 191 Wetlands: Functioning, Biodiversity Conservation and Restoration, this book provides a broad and well-integrated overview of recent major scientific results in wetland science and their applications in natural resource management issues.After an introduction to the field, a group of internationally known experts summarizes the state of the art on an array of topics, divided into four sections:-The Role of Wetlands for Integrated Water Resources Management: Putting Theory into Practice-Wetland Science for Environmental Management-Wetland Biogeochemistry-Wetlands and Climate Change Worldwide The volume will be useful to wetland scientists and natural resource managers, as well as environmental policy makers at all levels.
|
|
| 36. |
- Waara, Sylvia, 1958-, et al.
(author)
-
Towards Recommendations for Design of Wetlands for Post-Tertiary Treatment of Waste Water in the Baltic Sea Region – Gdańsk Case Study
- 2014
-
Conference paper (other academic/artistic)abstract
- 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.
|
|
