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  • 1.
    Andersson, Erik
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för energi-, miljö- och byggteknik.
    Nilsson, Martin
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för energi-, miljö- och byggteknik.
    Tillskottsvatten i spillvattennät: Underlag för framtida åtgärder i Fengersfors2015Independent thesis Basic level (university diploma), 15 poäng / 22,5 hpOppgave
    Abstract [sv]

    Vatten från avlopp innehåller förhöjda nivåer av kväve och fosfor som reningsverken tvingas hantera. Vid dålig rening släpps dessa ämnen ut i sjöar och andra vattendrag, vilket kan leda till övergödning. I det dalsländska samhället Fengersfors används två mindre biodammar för rening av avloppsvatten. Biodammarna uppfyller inte myndigheternas reningskrav, vilket har föranlett kommunen att uppgradera anläggningen. Vid utbyggnad av reningsanläggningen krävs det att dagens volymer av tillskottsvatten reduceras. Detta för att en dimensionering skall vara möjlig i proportion till samhällets storlek. Tillskottsvatten är övrigt vatten som når reningsverken utöver bad-, disk-, klosett- och tvättvatten. Exempel på tillskottsvatten kan vara vatten från nederbörd och grundvatten via inläckage, felkopplingar och överläckage. Man eftersträvar att minimera andelen tillskottsvatten i avloppsvattnet. Detta för att undvika kostnadskrävande reningsprocesser.

    Syftet med studien är att undersöka hur flödet av tillskottsvatten kan minskas till de biodammar som idag renar Fengersfors spillvatten. Studien skall besvara följande fråga: Vilka källor till tillskottsvatten finns i Fengersfors idag och vilka åtgärder bör kommunen prioritera för att uppnå sitt mål om att minska andelen tillskottsvatten i spillvattennätet?

    Att kartlägga källor och volymer av tillskottsvatten i avloppsledningsnätet är ett tidskrävande arbete. För att komma till rätta med problemet utan kostnadskrävande dupliceringsåtgärder är det viktigt att först skapa en bild över området. I denna studie görs detta genom fyra undersökningsmoment: fältinventering av bostadsbebyggelse, fältinventering av ytavledning, undersökning av grundvattennivåer och spårfärgning av osäkra kopplingar. Momenten är lätta att utföra och behöver inte utföras av personer med särskild kompetens. Undersökningsmomenten sammanställs i två översiktskartor, Fengersfors Norra och Fengersfors Södra. Kartorna används därefter för enklare beräkningar över vilka områden som bidrar med stora volymer tillskottsvatten.

    Flertalet fastigheter i Fengersfors har sina takytor anslutna till spillvattennätet. Enklare åtgärder, som omkoppling till utkastare med tät vattenavledare, kan reducera volymen nederbördsvatten som når biodammarna. Dikningsunderhållet är eftersatt i hela Fengersfors, vilket medfört att trummor och brunnar satts igen. Ett fungerande dikessystem är nödvändigt för transport av dag- och dräneringsvatten till recipient. Under spårfärgningsarbetet hittades delar av dagvattenledningar som inte fanns med i ledningskartan. Kartor kan nu uppdateras och bli en viktig pusselbit för framtida åtgärder. Resultaten visar också att cirka 60 procent av det vatten som når reningsanläggningen i Fengersfors består av dränerat grundvatten, vilket gör reningen ineffektiv och en utbyggnad svår att dimensionera. Studien ger en fingervisning över vilka områden som behöver åtgärdas eller utredas vidare av kommunen.

  • 2.
    Berggren, Christian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Dig or no dig?: En jämförelse mellan schaktfria tekniker och konventionell schakt vid VA-produktion.2015Independent thesis Basic level (university diploma), 15 poäng / 22,5 hpOppgave
    Abstract [sv]

    Sveriges offentliga vatten- och avloppsnät består av 191 000 km vatten- och avloppsledningar. Det renoveras årligen ca 380 km för lite för att hålla förnyelsetakten i takt med åldrandet av ledningarna. Renoveringarna kostar stora summor pengar vilket lär vara en av de största anledningarna till att det renoveras i för liten utsträckning. För att hålla igång produktionen i Sveriges VA-sektor behöver både ekonomi och tidsåtgång ses över.

    Detta arbete jämför ekonomin i olika förläggningsmetoder för vatten och avloppsledningar. Arbetet tar även upp utsläpp av koldioxidekvivalenter under produktion av VA-ledningar. Metoderna som har tagits upp är konventionell schakt, styrd borrning och relining. Inom styrd borrning har det tittats på JT- och AT-borrning. För relining är de granskade metoderna slip-lining och closed-fit.

    Arbetet har gjorts för Skanska Väg och Anläggning Väst som är en del av Skanska Sverige AB. Jämförelsen har utförts med en litteraturstudie som bakgrund. Kalkyler från utförda och pågående projekt samt intervjuer med olika entreprenadföretag har varit underlag för den jämförande studien kring ekonomi och miljö.

    Resultaten visar på att schaktfria tekniker släpper ut mindre koldioxid än konventionell schakt vilket inte är konstigt då det vid schaktning hanteras mycket större jordmassor. I avseende på ekonomi kan sägas att underlaget för resultatet är undermåligt men vad som är mest kostnadseffektivt varierar beroende på projekt. En generalisering kan dock göras för schaktfria metoder. Dessa tenderar att bli mer lönsamma ju djupare och längre entreprenaden är samt desto färre serviser och förgreningar det är på ledningen. Styrd borrning begränsas av det borrslam som blir en restprodukt vid produktion med metoden. För grövre ledningsdimensioner blir omhändertagandet av slammet en stor kostnad som i vissa fall kan göra det olönsamt att borra. Generellt kan sägas att styrd borrning i grövre dimensioner kräver skyddsvärda objekt ovan mark för att nå ekonomisk lönsamhet.

  • 3.
    Govindarajan, Venkatesh
    Department of Hydraulic and Environmental Engineering, Norwegian University of Science and Technology, S P Andersensv 5, Valgrinda, NO-7491 Trondheim, Norway.
    Changes in material flows, treatment efficiencies and environmental load-shifting in the wastewater treatment sector Part II: Case study of Norway2009Inngår i: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 30, nr 11, s. 1131-1143Artikkel i tidsskrift (Fagfellevurdert)
  • 4.
    Govindarajan, Venkatesh
    Norwegian University for Science & Technology, Norway.
    Cost-benefit analysis: Leakage reduction by rehabilitating old water pipelines: Case study of Oslo (Norway)2012Inngår i: Urban Water Journal, ISSN 1573-062X, Vol. 9, nr 4, s. 277-286Artikkel i tidsskrift (Fagfellevurdert)
  • 5.
    Govindarajan, Venkatesh
    Norwegian University of Science & Technology, Trondheim.
    Malaysian Water tariff influences water-saving habits2011Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 103, nr 7, s. 32-34Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 6.
    Govindarajan, Venkatesh
    Norwegian University for Science & Technology, Norway.
    Sisyphean struggle or Pyrrhic victory ?2014Inngår i: Problemy Ekorozwoju, ISSN 1895-6912, E-ISSN 2080-1971, Vol. 9, nr 2, s. 73-77Artikkel i tidsskrift (Fagfellevurdert)
  • 7.
    Govindarajan, Venkatesh
    Norwegian University for Science & Technology, Norway.
    Testing different rehabilitation options in the drinking water pipeline network in Oslo using the Dynamic Metabolism Model2014Inngår i: Vatten, ISSN 0042-2886, Vol. 70, nr 4, s. 215-224Artikkel i tidsskrift (Annet vitenskapelig)
  • 8.
    Govindarajan, Venkatesh
    Norwegian University of Science & Technology, Trondheim, Norway.
    The EU TRUST project: Coming together to seek common solutions for water utilities2012Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 104, nr 11, s. 52-54Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    TRUST is an acronym for Transition to the Urban Water Services of Tomorrow. Just into its second year, this four-year European Union project consists of a consortium that is split into eight work areas (which in turn are segmented into many work packages), focusing on different aspects of the project. These eight work areas are not islands of expertise working in isolation in different countries in Europe, but cooperating and collaborating team members actively exchanging and sharing information among themselves to ensure that progress toward the end goals is ensured and expedited.

  • 9.
    Govindarajan, Venkatesh
    Norwegian University for Science & Technology, Norway.
    Urban Water System metabolism assessment using WaterMet(2) model2014Inngår i: 12TH INTERNATIONAL CONFERENCE ON COMPUTING AND CONTROL FOR THE WATER INDUSTRY, CCWI2013 / [ed] Brunone, B; Giustolisi, O; Ferrante, M; Laucelli, D; Meniconi, S; Berardi, L; Campisano, A, Elsevier, 2014, Vol. 70, nr 1, s. 113-122Konferansepaper (Fagfellevurdert)
  • 10.
    Govindarajan, Venkatesh
    Norwegian University of Science & Technology, Trondheim, Norway.
    Wastewater treatment in Norway: An overview2013Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 105, nr 5, s. 92-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The challenges of providing services to growing populations multiply, as demonstrated by the trials faced in Norway as it searched for effective ways of addressing a growing wastewater treatment problem.

  • 11.
    Govindarajan, Venkatesh
    Norwegian University of Science & Technology.
    WaterMet2: A tool for integrated analysis of sustainability-based performance of urban water systems2014Inngår i: Drinking Water Engineering and Science Discussions, ISSN 1996-9473, E-ISSN 1996-9481, Vol. 7, nr 1, s. 63-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents the "WaterMet2" model for long-term assessment of urban water system (UWS) performance which will be used for strategic planning of the integrated UWS. WaterMet2 quantifies the principal water-related flows and other metabolism-based fluxes in the UWS such as materials, chemicals, energy and greenhouse gas emissions. The suggested model is demonstrated through sustainability-based assessment of an integrated real-life UWS for a daily time-step over a 30-year planning horizon. The integrated UWS modelled by WaterMet2 includes both water supply and wastewater systems. Given a rapid population growth, WaterMet2 calculates six quantitative sustainability-based indicators of the UWS. The result of the water supply reliability (94%) shows the need for appropriate intervention options over the planning horizon. Five intervention strategies are analysed in WaterMet2 and their quantified performance is compared with respect to the criteria. Multi-criteria decision analysis is then used to rank the intervention strategies based on different weights from the involved stakeholders' perspectives. The results demonstrate that the best and robust strategies are those which improve the performance of both water supply and wastewater systems.

  • 12.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Azrague, Kamal
    SINTEF Bldg & Infrastruct, Water & Environm Res Grp, N-7465 Trondheim, Norway.
    Bell, Stig
    Municipal Oppegard, Water Wastewater & Renovat Sect, N-1412 Sofiemyr, Norway.
    Eikebrokk, Bjornar
    SINTEF Bldg & Infrastruct, Water & Environm Res Grp, N-7465 Trondheim, Norway.
    Triple bottom line assessment of raw water treatment: Methodology and application to a case study in the municipality of Oppegard in south-eastern Norway2015Inngår i: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 36, nr 15, s. 1954-1965Artikkel i tidsskrift (Fagfellevurdert)
  • 13.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Brattebo, Helge
    Norwegian University for Science & Technology, Norway.
    Analysis of chemicals and energy consumption in water and wastewater treatment, as cost components: Case study of Oslo, Norway2011Inngår i: Urban Water Journal, ISSN 1573-062X, Vol. 8, nr 3, s. 189-202Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Adopting a systems-approach to an urban water and wastewater system, while applying a triple bottom line strategy to management, entails a careful analysis of all the sub-systems and components thereof with a view to improving service levels, optimising expenditure, augmenting investments, and also reducing the life-cycle environmental impacts associated with setting up, maintaining and operating the system. The scope for optimising expenses is system-wide, though it varies from one sub-system to another, depending on inherent lock-ins and external factors beyond the direct control of the water and wastewater utility. Optimising the consumption of energy and chemicals and improving the cost-efficiency thereof, is always on the agenda of water treatment plants (WTPs) and wastewater treatment plants (WWTPs). This paper analyses the consumption of and the expenditure on chemicals and energy at Oslo's WTPs and WWTPs over time. Energy and chemicals for water and wastewater treatment, on an average account for 10.8% of the total operational expenses in the water supply sub-system and 13.7% for the wastewater handling sub-system. There is a perceptible increase in this share from 5.2% in 2004 to 14.9% in 2009 for water and 12.3% to 14.2% for wastewater. Chemicals cost more than energy for the WWTPs, while it was the other way round for the WTPs. The total real cost of energy and chemicals per cubic metre, in year-2007 currency, was between 4 and 5.2 Euro cents for the WTPs, and between 1 and 4.5 Euro cents for the WTPs. The total (WTP + WWTP) per-capita real costs of energy and chemicals, expressed in year-2007 currency, rose from around 10 Euros in year 2000 to about 12.2 Euros in year 2007.

  • 14.
    Govindarajan, Venkatesh
    et al.
    Norwegian University of Science and Technology, Trondheim, Norway.
    Brattebo, Helge
    Norwegian University of Science and Technology, Trondheim, Norway.
    Changes in material flows, treatment efficiencies and shifting of environmental loads in the wastewater treatment sector.: Part I: Case study of the Netherlands2009Inngår i: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, Vol. 30, nr 11, s. 1111-1129Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The material that is separated from wastewater in wastewater treatment plants has to be transferred from the water phase to the atmosphere, lithosphere, and/or biosphere (and also the technosphere). After the initial discharges into the different environmental media (and the technosphere), there are further 'inter-sphere' leakages or redirections. However, these happen over protracted periods of time and have not been accounted for in this paper. The paper presents a case study on the wastewater treatment plants in the Netherlands, examines how the degree of separation of COD (BOD), nitrogen, phosphorus and heavy metals from the wastewater have increased over time, and studies the changes in proportions separated out to the atmosphere and lithosphere. The hydrosphere has benefited from a decline in the degree of eutrophication and marine/fresh water toxicity, owing to the favourable combination of higher degrees of separation, over time, and source control, especially in the industrial sector. Global warming is a major concern owing to the increasing conversion of COD to carbon dioxide (and methane). Heavy metal and nitrogen emissions have been curbed thanks to source reduction within industries. Technologies have, of course, enabled some mitigation of the problems associated with atmospheric (global warming and toxicity) and lithospheric (toxicity) pollution, though these are beyond the scope of this paper, which assumes a hypothetical worst-case scenario in this regard for the study period 1993-2005.

  • 15.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Brattebo, Helge
    Norwegian University for Science & Technology, Norway.
    Environmental impact analysis of chemicals and energy consumption in wastewater treatment plants: Case study of Oslo, Norway2011Inngår i: Water Science and Technology: Water Supply, ISSN 1606-9749, E-ISSN 1607-0798, Vol. 63, nr 5, s. 1081-1031Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Brattebo, Helge
    NTNU, Norway.
    Sægrov, Sveinung
    NTNU, Norway.
    Behzadian, Kouroush
    University of Exeter, UK.
    Kapelan, Zoran
    Metabolism-modelling approaches to long-term sustainability assessment of urban water services2015Inngår i: Urban Water Journal, ISSN 1573-062X, s. 1-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is a discernible need for a holistic, long-term and sustainability approach in decision-making in water and wastewater utilities around the world. Metabolism-based modelling, which can quantify various flows within an urban water system (UWS), has shown its effective usability for a more comprehensive understanding of the impacts of intervention strategies and can be used by any water utility for future planning of UWS. This study presents the main principles of a holistic Sustainability Assessment Framework which can be simulated by using two analytical, conceptual, mass-balance-based models to quantify relevant key performance indicators (KPIs) associated with the metabolic flows of the urban water cycle. These two models are WaterMet2 (WM2) and dynamic metabolism model (DMM), developed recently under the aegis of the EU TRUST (Transitions to the Urban Water Services of Tomorrow) project. There are clear differences between the two models which make them useful in different contexts and circumstantial situations. DMM is a mass-balance consistent model which quantifies and presents annually-aggregated performance values for system wide energy consumption, emissions, environmental impacts and costs for the entire UWS though it is also possible to derive corresponding indicators for individual sub-systems (e.g. water distribution and wastewater transport). WM2 is the opposite of this, it is a distributed metabolism model which simulates water related and other resource flows throughout the UWS components with a higher resolution both spatially (e.g. multiple water resources and service reservoirs) and temporally (e.g. daily and monthly), and thereby is useful in contexts where utilities would like to focus on further details of the UWS metabolism with the aim to understand and solve specific problems. Overall, these two complementary metabolism-based approaches enable any water utility to quantitatively explore and understand the influences of different external drivers and intervention strategies on future performance profiles linked to any physical, environmental and economic criteria.

  • 17.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Didi, Mohamed Ahmed
    Norwegian University for Science & Technology, Norway.
    Mujthaba, Ahmed
    Norwegian University for Science & Technology, Norway.
    Male makes the most of limited land and freshwater2011Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 103, nr 5, s. 44-50Artikkel i tidsskrift (Annet vitenskapelig)
  • 18.
    Govindarajan, Venkatesh
    et al.
    Norwegian university of science and technology, Trondheim, Norway.
    Hammervold, Johanne
    Brattebo, Helge
    Norwegian university of science and technology, Trondheim, Norway.
    Combined MFA-LCA for analysis of wastewater pipeline networks: Case study of Oslo (Norway).2009Inngår i: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 13, nr 4, s. 532-550Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Oslo's wastewater pipeline network has an aging stock of concrete, steel, and polyvinyl chloride (PVC) pipelines, which calls for a good portion of expenditures to be directed toward maintenance and investments in rehabilitation. The stock, as it is in 2008, is a direct consequence of the influx of pipelines of different sizes, lengths, and materials of construction into the system over the years. A material flow analysis (MFA) facilitates an analysis of the environmental impacts associated with the manufacture, installation, operation, maintenance, rehabilitation, and retirement of the pipelines. The forecast of the future flows of materials-which, again, is highly interlinked with the historic flows-provides insight into the likely future environmental impacts. This will enable decision makers keen on alleviating such impacts to think along the lines of eco-friendlier processes and technologies or simply different ways of doing business. Needless to say, the operation and maintenance phase accounts for the major bulk of emissions and calls for energy-efficient approaches to this phase of the life cycle, even as manufacturers strive to make their processes energy-efficient and attempt to include captive renewable energy in their total energy consumption. This article focuses on the life cycle greenhouse gas emissions associated with the wastewater pipeline network in the city of Oslo.

  • 19.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Nersund Larsen, Hogne
    Energy and Environment, AsplanViak, Trondheim, Norway.
    Water-energy nexus in urban water utilities: A brief Norwegian outlook2015Inngår i: Vatten, ISSN 0042-2886, Vol. 71, nr 2, s. 101-109Artikkel i tidsskrift (Annet vitenskapelig)
  • 20.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Ramprakash, Govindarajan
    Norwegian University for Science & Technology, Norway.
    Metabolism: beyond the preserve of biological sciences2014Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 106, nr 7, s. 44-48Artikkel i tidsskrift (Fagfellevurdert)
  • 21.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Saegrov, Sveinung
    Norwegian University for Science & Technology, Norway.
    Brattbo, Helge
    Norwegian University for Science & Technology, Norway.
    Dynamic metabolism modelling of urban water services - demonstrating effectiveness as a decision-support tool for Oslo, Norway2014Inngår i: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 61, nr 1, s. 19-33Artikkel i tidsskrift (Fagfellevurdert)
  • 22.
    Govindarajan, Venkatesh
    et al.
    Norwegian University of Science and Technology (NTNU) at Trondheim, Norway.
    Ugarelli, Rita
    NTNU, SINTEF.
    Kristiansen, Per
    Oslo VA.
    Oslo consumers willing to pay more for improved services: Interview with Per Kristiansen, Chief of Oslo VAV2010Inngår i: Journal of American Water Works Association, ISSN 0003-150X, Vol. 102, nr 11, s. 26-29Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 23.
    Graversgaard, Morten
    et al.
    Aarhus University, Denmark.
    Hedelin, Beatrice
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för miljö- och livsvetenskaper (from 2013). Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper, Centrum för klimat och säkerhet.
    Smith, Laurence
    SOAS University of London, UK.
    Gertz, Flemming
    SEGES, Landbrug & Fødevarer F.M.B.A., Denmark.
    Højberg, Anker Lajer
    Geological Survey of Denmark and Greenland (GEUS), Denmark.
    Langford, John
    University of Melbourne, Australia.
    Martinez, Grit
    Ecologic Institute, Germany.
    Mostert, Erik
    Delft University of Technology, The Netherlands.
    Ptak, Emilia
    Aarhus University, Denmark.
    Peterson, Heidi
    University of Minnesota, MN, USA; International Plant Nutrition Institute, MN, USA.
    Stelljes, Nico
    Ecologic Institute, Germany.
    van den Brink, Cors
    Royal Haskoning DHV, The Netherlands; Groningen University, The Netherlands.
    Refsgaard, Jens Christian
    Geological Survey of Denmark and Greenland (GEUS), Denmark.
    Opportunities and barriers for water co-governance: A critical analysis of seven cases of diffuse water pollution from agriculture in Europe, Australia and North America2018Inngår i: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 10, nr 5, artikkel-id 1634Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Diffuse Water Pollution from Agriculture (DWPA) and its governance has received increased attention as a policy concern across the globe. Mitigation of DWPA is a complex problem that requires a mix of policy instruments and a multi-agency, broad societal response. In this paper, opportunities and barriers for developing co-governance, defined as collaborative societal involvement in the functions of government, and its suitability for mitigation of DWPA are reviewed using seven case studies in Europe (Poland, Denmark, Sweden, The Netherlands and UK), Australia (Murray-Darling Basin) and North America (State of Minnesota). An analytical framework for assessing opportunities and barriers of co-governance was developed and applied in this review. Results indicated that five key issues constitute both opportunities and barriers, and include: (i) pressure for change; (ii) connected governance structures and allocation of resources and funding; (iii) leadership and establishment of partnerships through capacity building; (iv) use and co-production of knowledge; and (v) time commitment to develop water co-governance

  • 24.
    Johansson, Emma
    et al.
    Karlstads universitet.
    Govindarajan, Venkatesh
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Wastewater treatment plants as energy producers: Comparison of status quo in Sweden and India2018Inngår i: Vatten, ISSN 0042-2886, Vol. 73, nr 151, artikkel-id 160Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    As the population of the world rises and economies grow, both energy and water will be needed in ever-increasing quantities. There is a delicate balance between these two resources called the energy-water (or the water-energy) nexus. One way to reduce the energy consumption associated with wastewater treatment is to use the sludge produced during the process to generate biogas. In most countries in the developed world, the coverage, standards and reliability of wastewater treatment are high.  But as the countries in the developing world are striving towards the living standards of those in the developed world, even as they combat population pressure, it is  imperative that they  learn from the experiences (the mistakes which occurred during the ‘learning-by-doing’ process) of the developed world. In this paper, Sweden has been used as a proxy for the developed world with a well-functioning sanitation infrastructure and reliable power supply; and India (the home country of one of the coauthors) is a proxy for the developing world which lacks the same. A very important starting point for development would be to educate people about the long-term socio-economic and environmental benefits of wastewater treatment

     

  • 25.
    Naqvi, Salman Raza
    et al.
    Univ Twente, Fac Engn Technol, Enschede, Netherlands; Natl Univ Sci & Technol, Islamabad, Pakistan.
    Tariq, R.
    Natl Univ Sci & Technol, Islamabad, Pakistan.
    Hameed, Z.
    Natl Univ Sci & Technol, Islamabad, Pakistan.
    Ali, I.
    King Abdulaziz Univ, Dept Chem, Rabigh, Saudi Arabia; King Abdulaziz Univ, Dept Mat Engn, Rabigh, Saudi Arabia.
    Taqvi, S. A.
    Univ Teknol PETRONAS, Dept Chem Engn, Seri Iskandar, Malaysia; NED Univ Engn & Technol, Chem Engn Dept, Karachi 75270, Pakistan.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Niazi, M. B. K.
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, Islamabad, Pakistan.
    Noor, T.
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, Islamabad, Pakistan.
    Farooq, W.
    KFUPM, Dept Chem Engn, Dhahran, Saudi Arabia.
    Pyrolysis of high-ash sewage sludge: Thermo-kinetic study using TGA and artificial neural networks2018Inngår i: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 233, s. 529-538Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pyrolysis of high-ash sewage sludge (HASS) is a considered as an effective method and a promising way for energy production from solid waste of wastewater treatment facilities. The main purpose of this work is to build knowledge on pyrolysis mechanisms, kinetics, thermos-gravimetric analysis of high-ash (44.6%) sewage sludge using model-free methods & results validation with artificial neural network (ANN). TG-DTG curves at 5,10 and 20 °C/min showed the pyrolysis zone was divided into three zone. In kinetics, E values of models ranges are; Friedman (10.6–306.2 kJ/mol), FWO (45.6–231.7 kJ/mol), KAS (41.4–232.1 kJ/mol) and Popescu (44.1–241.1 kJ/mol) respectively. ΔH and ΔG values predicted by OFW, KAS and Popescu method are in good agreement and ranged from (41–236 kJ/mol) and 53–304 kJ/mol, respectively. Negative value of ΔS showed the non-spontaneity of the process. An artificial neural network (ANN) model of 2 * 5 * 1 architecture was employed to predict the thermal decomposition of high-ash sewage sludge, showed a good agreement between the experimental values and predicted values (R2 ⩾ 0.999) are much closer to 1. Overall, the study reflected the significance of ANN model that could be used as an effective fit model to the thermogravimetric experimental data. © 2018 Elsevier Ltd

  • 26. Osorio, Andrea Diaz
    et al.
    Govindarajan, Venkatesh
    Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
    Integrated Management Spells Success for Medellin, Colombia's, Water and Wastewater Utility2013Inngår i: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 105, nr 3, s. 78-82Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The city of Medellin is the second largest urban area in Colombia. The state-owned company, Empresas Publicas de Medellin E.S.P. (EPM), provides water supply and wastewater treatment services to more than 3.5 million people in the city and nine other smaller towns in the conurbation. EPM also provides public services other than water supply and wastewater treatment. Eduardo Cadavid Restrepo, director of the department of water management at EPM, described the current status, challenges, and future plans for the water supply and sanitation system in Medellin in this interview (conducted by e-mail in Spanish and later translated to English) with Andrea Diaz Osorio and Govindarajan Venkatesh.

  • 27.
    Ugarelli, Rita
    et al.
    Bologna university, Bologna, Italy.
    Govindarajan, Venkatesh
    Department of Hydraulic and Environmental Engineering, NTNU, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
    Brattebo, Helge
    Norwegian university of science and technology, Trondheim, Norway.
    Di Federico, Vittorio
    Bologna university, Bologna, Italy.
    Saegrov, Sveinung
    Norwegian university of science and technology, Trondheim, Norway.
    Historical analysis of blockages in wastewater pipelines in Oslo and diagnosis of causative pipeline characteristics.2010Inngår i: Urban Water Journal, ISSN 1573-062X, Vol. 7, nr 6, s. 335-343Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The city of Oslo is evaluating strategies for the selection of appropriate materials for the pipelines and manholes of its wastewater network. The overarching motive is to minimise construction-related failures over the system lifetime and also ensure that it is able to avert flooding events. This paper analyses the blockage records of the last 16 years (1991-2006) in the wastewater pipeline network of Oslo. For the purpose of the analysis, the pipeline stock is categorised on the basis of pipe diameter, material of fabrication, slope and age. Proneness to blockages is studied and attempts are made to correlate the same to the size, material, slope and age. The analyses performed confirm that older and small diameter sewage pipelines made of concrete, laid almost horizontal to the ground surface are the high-priority candidates, and more importantly enables one to compare among the different categories and classes of pipelines.

  • 28.
    Ugarelli, Rita
    et al.
    Bologna University, Bologna, Italy.
    Govindarajan, Venkatesh
    Norwegian university of technology and science, Trondheim, Norway.
    Brattebø, Helge
    Norwegian university of technology and science, Trondherim, Norway.
    Di Federico, Vittorio
    Bologna university, Bologna, italy.
    Sægrov, Sveinung
    SINTEF, Trondheim, Norway.
    Asset management of urban wastewater pipeline networks2010Inngår i: Journal of Infrastructure Systems, ISSN 1076-0342, E-ISSN 1943-555X, Vol. 16, nr 2, s. 112-121Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pipelines account for the lion’s share of the lifetime costs of any typical urban wastewater collection. While the deterioration of pipeline is the obvious “frontline” reason to adopt asset management practices, a more overarching driver is the need to gravitate toward sustainable development and set short- and long-term objectives encompassing economic, social, and environmental goals. Optimizing the expenses and providing the required levels of service to customers are the twin targets of wastewater utilities. Oslo Vann og Avløpsetaten—the water/wastewater utility in the Norwegian capital, considered as case study in this paper, is sprucing up its data bank, rightly realizing that a very effective information management system is the spine of asset management.

  • 29.
    Ugarelli, Rita
    et al.
    Bologna university, Italy.
    Govindarajan, Venkatesh
    Norwegian University of Science and Technology, Trondheim, Noraway.
    Brattebø, Helge
    Norwegian University of Science and Technology, Trondheim, Norway.
    Sægrov, Sveinung
    SINTEF, Trondheim, Norway.
    Importance of investment decisions and rehabilitation approaches in an ageing wastewater pipeline network.: A case study of Oslo (Norway)2008Inngår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 58, nr 12, s. 2279-2293Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As Oslo Vann og Avlopsetaten (VAV, meaning Water and Sewage Department) looks into the future, it is faced with a quandary-to replace old pipelines or to continue maintaining them. The primary goal is to improve the level of service. The secondary goals are to rejuvenate the system and stem the decline in capital value. In 1991-2006, the Operation and Maintenance expenses (O&M) were far higher than the investments, and the network aged as its capital value plummeted. However, if the funds are insufficient, the self-financing Oslo VAV would have to turn to the consumers for help. Will the consumers pay more to have a 'younger' system? What if they are happy with the 'status quo' and are unconcerned about the falling capital value? Should the pipelines be depreciated over a longer period than the 40 years which is adopted now? Should the economic method be replaced by a more engineering-based method, whereby the pipes are assessed 'on merit'-on the basis of their service lives? There are numerous issues and a good decision will ease the road ahead. This paper, using Life Cycle Costing Analysis (LCCA) and scenarios therein, looks at how Oslo VAV could strike a balance between expending on O&M, investing in upgrading the network, and decelerating the ageing of the network while augmenting the capital value, and what is the best attainable set of targets they could aim for, at the end of the next 20 years. The two approaches mentioned above are compared with each other. It is seen that a rehabilitation programme based on the pipes performance approach is preferable to one guided by an economic lifetime approach, when the motive is to optimise expenditure and also improve the level of service.

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