| 1. |
- Saagi, R., et al.
(författare)
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City-wide model-based analysis of heat recovery from wastewater using an uncertainty-based approach
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 820
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Tidskriftsartikel (refereegranskat)abstract
- Around 90% of the energy requirement for urban water systems management is for heating domestic tap water. In addition, the energy content of wastewater is mainly in the form of heat (85%). Hence, there is an obvious interest in recovering a large portion of this heat. However, city-wide scenario analyses that evaluate heat recovery at various locations while considering impacts on wastewater treatment plant (WWTP) performance are currently very limited. This study presents a comprehensive model-based city-wide evaluation considering four different heat recovery locations (appliance, household, precinct and WWTP effluent) for a Swedish city with varying degrees of implementation using an uncertainty-based approach. Results show that heat recovery at the appliance level, with heat exchangers installed at 77% of the showers at domestic households, leads to a mean energy recovery of 127 MWh/day with a 0.25 °C reduction in mean WWTP inlet temperature compared to the default case without heat recovery. The highest mean temperature reduction compared to the default case is 1.5 °C when heat is recovered at the precinct level for 77% of the domestic wastewater flow rate. Finally, the impact on WWTP nitrification capacity is negligible in this case due to its large existing capacity and design. © 2022 The Authors
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| 2. |
- Saagi, R., et al.
(författare)
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Modelling temperature dynamics in sewer systems – Comparing mechanistic and conceptual modelling approaches
- 2021
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 84:9, s. 2335-2352
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Tidskriftsartikel (refereegranskat)abstract
- The vast majority of the energy consumed for urban water services is used to heat tap water. Heat recovery from wastewater is consequently an area of rapidly growing concern, both in research and by commercial interest, promoting the path towards a circular economy. To facilitate a system-wide evaluation of heat recovery from wastewater, this paper compares two one-dimensional models (mechanistic and conceptual) that can describe wastewater temperature dynamics in sewer pipe systems. The models are applied to successfully predict downstream wastewater temperature for sewer stretches in two Swedish cities (Linköping and Malmö). The root mean squared errors for the mechanistic model (Linköping Dataset1 – 0.33 °C; Linköping Dataset2 – 0.28 °C; Malmö – 0.40 °C) and the conceptual model (Linköping Dataset1 – 0.32 °C; Linköping Dataset2 – 0.20 °C; Malmö – 0.44 °C) indicate that both models have similar predictive capabilities, encouraging the use of conceptual models to reduce data requirements and model calibration efforts. Both models are freely distributed and can be easily integrated with wastewater generation and treatment models to facilitate system-wide wastewater temperature dynamics analysis. © 2021 The Authors.
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| 3. |
- Vinas, Victor, 1988, et al.
(författare)
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Overview of microbial risks in water distribution networks and their health consequences : Quantification, modelling, trends, and future implications
- 2019
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Ingår i: Canadian journal of civil engineering (Print). - : Canadian Science Publishing. - 0315-1468 .- 1208-6029. ; 46:3, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- The water distribution network (WDN) is usually the final physical barrier preventing contamination of the drinking water before it reaches consumers. Because the WDN is at the end of the supply chain, and often with limited online water quality monitoring, the probability of an incident to be detected and remediated in time is low. Microbial risks that can affect the distribution network are: intrusion, cross-connections and backflows, inadequate management of reservoirs, improper main pipe repair and (or) maintenance work, and biofilms. Epidemiological investigations have proven that these risks have been sources of waterborne outbreaks. Increasingly since the 1990s, studies have also indicated that the contribution of these risks to the endemic level of disease is not negligible. To address the increasing health risks associated to WDNs, researchers have developed tools for risk quantification and risk management. This review aims to present the recent advancements in the field involving epidemiological investigations, use of quantitative microbial risk assessment (QMRA) for modelling, risk mitigation, and decision-support. Increasing the awareness of the progress achieved, but also of the limitations and challenges faced, will aid in accelerating the implementation of QMRA tools for WDN risk management and as a decision-support tool.
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| 4. |
- Schade, Jutta, et al.
(författare)
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Greenhouse gas emissions and sustainability of green roofs and stormwater systems at a district level – comparisons with a life cycle perspective
- 2022
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Ingår i: Proceedings of LCM 2021: 10<sup>th</sup> International Conference on Life Cycle Management. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- To reach future climate targets, it is important to verify that materials and technologies used for construction are sustainable and have a minimal environmental impact. The goal of this project was to add a broad life cycle perspective for quantifying energy and greenhouse gas emission, from the upstream flow of the construction process and the operational phase by including buildings and stormwater systems at a district level. The hypothesis was that green roofs might have a higher impact on greenhouse gas emissions as more material is needed compared to a standard roof. In return, green roofs reduce and retain stormwater, which may reduce the risk of hydraulic overloading in connected stormwater systems. This may lead to reduced CO2 emission if an upgrade of existing systems is not necessary. To evaluate this complex issue, a framework was developed combining construction modelling, energy simulation, stormwater system modelling, and life cycle assessment. The result of this theoretical study indicates that green roofs reduce and retain stormwater but are in most cases not sufficient to reduce the risk of hydraulic overloading in connected stormwater systems. The results demonstrated that green roofs should be not solely implemented to reduce and retain stormwater in the Nordic climate.
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| 5. |
- Sjöstrand, Karin, et al.
(författare)
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The value of water—estimating water-disruption impacts on businesses
- 2021
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 13:11
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Tidskriftsartikel (refereegranskat)abstract
- As water serves as a necessary and often irreplaceable input in a range of goods and services, a disruption in water supply can cause lost production and sales for businesses. Thus, large benefits may be generated by reducing the risk of water disruptions. To enable selection of economically viable risk mitigation measures, the investment costs should be weighed against the benefits of risk mitigation. Consequently, quantitative estimates of the consequences of disruptions need to be available. However, despite the importance of water to businesses, the literature on their financial losses due to short and long-term water disruptions is still scarce. The aim of this paper is to estimate time-dependent water supply resiliency factors for economic sectors, i.e., a metric focusing on the level of output that businesses can uphold during a disruption, to contribute to better decision support for water supply planning and risk management. An online survey was used to gather data from 1405 companies in Sweden on consequences of complete and unplanned water supply outages. Results show that Food and beverage Manufacturing and Accommodation and food services are the two most severely affected sectors over all analyzed disruption durations. © 2021 by the authors
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| 6. |
- Andersson, Lisa, et al.
(författare)
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Implementering av innovativa systemlösningar för hållbar dagvattenhantering
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet Klimatsäkrade systemlösningar för urbana ytor syftar till att stärka städers förmåga att hantera ökad urbanisering och förändrat klimat, bland annat genom att utveckla innovativa systemlösningar för dagvattenhantering. I detta delprojekt har hinder och utmaningar för implementering av innovativa systemlösningar i stadsutvecklingsprocesser identifierats genom intervjuer med sakkunniga teknikexperter samt tjänstepersoner från olika förvaltningar. Som komplement har Svenskt Vattens publikationer P105 (Svenskt Vatten, 2011) och P110 (Svenskt Vatten, 2016) som är branschstandard för dagvattenhantering, samt utvalda kommuners policydokument analyserats för att undersöka hur dessa förhåller sig till innovativa systemlösningar för dagvattenhantering. Teoretisk utgångspunkt har varit studier kring vad som påverkar utveckling och spridning av tekniska innovationssystem (Bergek, 2008; Hellsmark, Bergek, Hellström, & Malmquist, 2014) samt teorier om innovation i offentlig sektor (Mulgan, 2007; Mulgan, 2014; Nählinder, 2013; Nählinder & Fogelberg Eriksson, 2017). De främsta faktorer som har identifierats påverka implementering av systemlösningar för dagvattenhantering är innovationskultur, samverkan vid planering, kunskap och ekonomi. För att överbrygga dessa hinder har rekommendationer för hållbar dagvattenhantering och uppdaterade riktlinjer för utformning av dagvattenstrategi utvecklats. För att underlätta samverkan samt val av dagvattenlösning har även ett beslutsstöd utvecklats för att kunna användas i ett tidigt skede vid planering (Brisvåg, 2017).
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| 7. |
- Arnell, Magnus, et al.
(författare)
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Aeration system modelling - case studies from three full-scale wastewater treatment plants
- 2015
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Ingår i: 9th IWA Symposium on Systems Analysis and Integrated Assessment (Watermatex 2015).
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Konferensbidrag (refereegranskat)abstract
- The water train of three WWTPs have been modelled following the procedures of the Benchmark Simulation Model (BSM) platform (Gernaey et al., 2014). Additionally the aeration system has been modelled to evaluate airflows and energy performance. The results for the airflow model are presented. The chosen airflow model is shown to be easy to apply and calibrate and robust for practical modelling cases. By simply adjusting the SOTE-polynomial, number of diffusors and airflow limitations the model replicates the real data at a level of detail suitable for most purposes where the evaluation is based on longer time averages. For peak demand evaluation the whole treatment model with influent characterization, model calibration and controllers need to be more detailed than done here. Modelling the airflow is important to allow for evaluation of air consumption, aeration energy performance and for communication of simulation results to plant staff and operators.
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| 8. |
- Arnell, Magnus, et al.
(författare)
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Evaluating Environmental Performance of Operational Strategies at Wastewater Treatment Plants
- 2016
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Ingår i: IWA World Water Congress and Exhibition 2016 (IWA 2016).
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Konferensbidrag (refereegranskat)abstract
- Multi-objectiveperformance assessment of operational strategies at wastewater treatment plants(WWTPs) is a challenging task. The holistic perspective applied to evaluationof modern WWTPs, including not only effluent quality but also, resourceefficiency and recovery, global environmental impact and operational cost callsfor assessment methods including both on and off-site effects. In this study amethod combining dynamic process models – including greenhouse gas (GHG)emissions and detailed energy models – and life cycle assessment was developed.The method is applied and calibrated to a large Swedish WWTP. In a performanceassessment study changing the operational strategy to chemically enhanced primarytreatment was performed and evaluated. The results show that the primaryobjectives, to enhance bio-methane production and reduce greenhouse gasemissions were reached. Bio-methane production increased by 14% and the globalwarming potential (GWP) decreased by 28%. However, the LCA revealed that due toincreased consumption of precipitation chemicals and additional carbon sourcedosing (methanol) the abiotic depletion of elements and fossil re-sourcesincreased by 77 and 305%, respectively. The results emphasise the importance ofusing plant-wide mechanistic models and life cycle analysis to capture thedynamics of the plant – e.g. dynamics of GHG emissions – and the potentialglobal environmental impact.
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| 9. |
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| 10. |
- Arnell, Magnus, et al.
(författare)
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Modellering av avloppsreningsverk för multikriteriebedömning av prestanda och miljöpåverkan
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Genom att använda detaljerade dynamiska modeller och kombinera resultat från årslånga simuleringar av ARV (såväl vatten- som slamlinjer) med livscykelanalys kan olika driftstrategier utvecklas och utvärderas utifrån en bred uppsättning hållbarhetskriterier fö att maximera resursutvinning och energieffektivitet samtidigt som vattenkvalitén bibehålls och driftskostnaderna kontrolleras. Metodiken har tillämpats vid en omfattande fallstudie av Käppalaverket.
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