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  • 51.
    Govindarajan, Venkatesh
    et al.
    Norwegian Univ Sci & Technol, Dept Hydraul & Environm Engn, N-7491 Trondheim, Norway.
    Elmi, Rashid Abdi
    Economic-environmental analysis of handling biogas from sewage sludge digesters in wastewater treatment plants for energy recovery: Case study of Bekkelaget wastewater treatment plant in Oslo, Norway2013In: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 58, no 10, p. 220-235Article in journal (Refereed)
  • 52.
    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).2009In: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 13, no 4, p. 532-550Article in journal (Refereed)
    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.

  • 53.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Hammervold, Johanne
    Norwegian University for Science & Technology, Norway.
    Brattebo, Helge
    Norwegian University for Science & Technology, Norway.
    Methodology for determining life-cycle environmental impacts due to material and energy flows in wastewater pipeline networks: A case study of Oslo (Norway)2011In: Urban Water Journal, ISSN 1573-062X, Vol. 8, no 2, p. 119-134Article in journal (Refereed)
  • 54.
    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 outlook2015In: Vatten, ISSN 0042-2886, Vol. 71, no 2, p. 101-109Article in journal (Other academic)
  • 55.
    Govindarajan, Venkatesh
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Nyflött, Åsa
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Bonnerup, Chris
    Stora Enso.
    Lestelius, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    An economic-environmental analysis of selected barrier coating materials used in packaging food products: A Swedish case study2017In: Environment, Development and Sustainability, ISSN 1387-585X, E-ISSN 1573-2975, Vol. 20, no 4, p. 1483-1497Article in journal (Refereed)
    Abstract [en]

    The purpose of a barrier coating in food packaging is primarily to increase the shelf life of the foodstuff contained within the packaging, preserve its colour, odour, taste and quality, and thereby reduce food wastage (both at retail outlets and households). While most publications hitherto have compared packaging and barrier-coating materials on the basis of their environmental impacts alone, this paper adopts a more holistic approach by factoring in the economic aspect as well. Four barrier material alternatives—starch, polyethylene, EVOH + kaolin and latex + kaolin are analysed. Two well-defined end-of-life handling scenarios, relevant to Sweden, are: one in which everything except starch is recycled, with starch being composted, and the other in which everything is incinerated. Among the several environmental impact categories which can be analysed, this paper considers only global warming. Two approaches are tested to combine the economic and environmental aspects—normalisation, weighting and aggregating on the one hand, and using the carbon tax to internalise the externality caused by GHG emissions on the other. For the set of weighting factors obtained thanks to a survey conducted by the authors (40.6% for environmental and 59.4% for economic), starch emerges as the most sustainable alternative, followed by polyethylene for both the end-of-life handling scenarios. This tallies with the result obtained by using the carbon tax for internalisation of the externality. The case study, methodology and results presented in this paper, will hopefully be a springboard for more detailed studies of this nature, under the umbrella of sustainability.

  • 56.
    Govindarajan, Venkatesh
    et al.
    Norwegian University for Science & Technology, Norway.
    Ramprakash, Govindarajan
    Norwegian University for Science & Technology, Norway.
    Metabolism: beyond the preserve of biological sciences2014In: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 106, no 7, p. 44-48Article in journal (Refereed)
  • 57.
    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, Norway2014In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 61, no 1, p. 19-33Article in journal (Refereed)
  • 58.
    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 VAV2010In: Journal of American Water Works Association, ISSN 0003-150X, Vol. 102, no 11, p. 26-29Article in journal (Other (popular science, discussion, etc.))
  • 59.
    Johansson, Emma
    et al.
    Karlstad University.
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Wastewater treatment plants as energy producers: Comparison of status quo in Sweden and India2018In: Vatten, ISSN 0042-2886, Vol. 73, no 151, article id 160Article in journal (Other academic)
    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

     

  • 60.
    Karlsson, Johan
    et al.
    Karlstad University.
    Stawreberg, Lena
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Material-flow analysis, energy analysis, and partial environmental-LCA of a district-heating combined heat and power plant in Sweden2017In: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 144, p. 31-40Article in journal (Refereed)
    Abstract [en]

    Combined heat and power (CHP) plants are a great improvement over waste-to-energy incineration plants supplying only heat, and power plants supplying only electricity. The primary purpose of a functioning CHP plant however, may be to provide district heating services, and thereby its main output will be heat energy. This paper is a case study commissioned by Karlskoga Energi och Miljö AB (KEMAB in short; Karlskoga Energy and Environment) in the Värmland State of south-central Sweden, and focuses on the functioning of the CHP plant owned and operated by the company. The life-cycles of the fuels used by the CHP – household/industrial waste, bio-oil, light fuel oil, wood waste, wood chips, a slaughterhouse-waste-derived product and peat to generate 202,222 MWh of heat, 119,234 MWh of steam and 28,220 MWh of electricity have been studied, and the carbon footprint calculated for year-2016. Using two sets of emissions factors for the combustion stage of the life-cycle, as part of a data uncertainty analysis, the total emissions were 44,000 tonnes carbon dioxide equivalents (CO2-eq) and 58,000 tonnes CO2-eq respectively. A quasi-realistic scenario analysis in which plastics are not available for incineration and have to be substituted with alternatives has also been carried out, and while wood waste has been suggested as the best alternative with regard to greenhouse gas (GHG) emissions, availability permitting, a combination of alternatives has been mooted as the practical option.

  • 61.
    Kjeang, Are
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology. Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Palm, Jenny
    2 IIIEEE, International Institute for Industrial Environmental Economics, Lund University, Lund, Sweden..
    Energy consulting services in the information age: literature review2017In: Energy, Sustainability and Society, ISSN 2192-0567, Vol. 7, no 30, p. 1-10Article in journal (Refereed)
  • 62.
    Kjeang, Are
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Palm, Jenny
    Lunds universitet.
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Local Energy Advising in Sweden: Historical Development and Lessons for Future Policy-Making2017In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 9, no 12, p. 1-13, article id 2275Article in journal (Refereed)
    Abstract [en]

    In Sweden, energy-consulting services, here referred to as local energy advising (LEA), have traditionally contributed to improving household energy efficiency. The aim of this article is to analyze the development of this service from the 1970s, when the consultancy came into being, to the present day, through a review of documents and published literature. The analysis enables the understanding of the evolution of local energy advising as a policy instrument, and provides valuable insights for the future. Local energy advising has often been subsidized by the Swedish government and used as a state policy measure rather than a municipal one. As a policy measure, the function of the service has changed over time. In the early period, the oil crisis was a fact and the local advisers were used to inform households. In the 1980s, however, the task of energy-advising was taken over by the energy companies in the spirit of market liberalization. In the 1990s, Sweden became a member of the European Union, and the emphasis was put on general information campaigns. Recently, the development of decentralized energy systems (including micro-energy systems) has necessitated targeting individuals with information. One important lesson to learn from the historical development of LEA is the imperativeness of providing energy advising at the local rather than the state level for better efficiency.

  • 63.
    Lestelius, Magnus
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013), Paper Surface Centre.
    Nyflött, Åsa
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Moons, Ellen
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Järnström, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013), Paper Surface Centre.
    Carlsson, Gunilla
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Bonnerup, Chris
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Oxygen permeabilityand economic-environmental impact studies of some polyvinyl alcohol dispersionbarrier coatings for packaging applications2017Conference paper (Other academic)
    Abstract [en]

    Purposes of employing barrier coatings in packaging, and in particular food packaging, can be to increase the shelf life, preserve colour, odour, and taste, and to protect from a harmful environment in general. Barrier coatings can thus help to reduce food waste along the value chain until end use. Including both materials choice for packaging and the possible fates of the used package, even further steps to provide greater knowledge for decisions on choices of packaging solutions. To that end, we have conducted several experimental and transport modeling studies on oxygen barrier coatings performance. The coating system of choice    has been dispersion coatings of poly vinyl alcohol (PVOH), with additions of kaolin. Physical and chemical features of the coatings were characterized to obtain information on polymer crystallinity, free volume and filler orientation as these characteristics are influential to the oxygen mass transport performance. In turn, the oxygen mass transport was also measured, both in steady state and dynamically. In so doing, we obtained information    useful for developing a general model to describe the oxygen permeability taking into account the physical and chemical features, described above, of the coating layer. Attempts on describing the interdependence and impact, for instance between crystalline and amorphous polymer regions and moisture, was added to the model. The model showed agreement to experimental data for PVOH-kaolin coating in this particular case. However, the basic permeability model has been applied to  many different polymers.

    To further explore the potential of these types of coating, which are technically possible to    produce in paperboard production, an economic-environmental impact comparison to other existing material solutions was made. Four barrier material alternatives – starch, polyethylene, ethyl vinyl alcohol (chosen as an alternative for PVOH, where data was difficult to obtain) and kaolin, and latex and kaolin, were analyzed with respect to cost and global warming potential. Weighting and comparing cost to environmental aspect, weighting    factors based on interviews with experts in the packaging value chain, starch emerges as the most sustainable alternative. However, previous coating and mass transport studies also shows how these renewable materials require some further technical development to be competitive.

    The mass transport model can serve as a tool for customizing barrier coatings and to predict the barrier performance, as permeability is obtained and thus shelf-life estimation is    possible. The overall concept, the combination of assessment of structural performance and the environmental studies, can be employed to find sustainable food packaging solutions.

  • 64.
    Mohammadi, Ali
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Sandberg, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Eskandari, Samieh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Life cycle assessment of combination of anaerobic digestion andpyrolysis: focusing on different options for biogas use2019In: Advances in Geosciences, ISSN 1680-7340, Vol. 49, p. 57-66Article in journal (Refereed)
    Abstract [en]

    The combination of anaerobic digestion and pyrolysistechnologies could be a novel energy-biochar productionsystem to maximize energy and nutrient recovery frompulp and paper mill sludge. Herein, the life-cycle energy productionand emissions reduction of sludge treatment from atypical pulp and paper mill were investigated, in which alternativeuses of biogas for industrial or household application,in different regions of the world, were assessed. Thethree scenarios considered for different end-uses of biogasare: (A) biogas for vehicle fuel in the transportation sectorin Sweden, (B) biogas for heat and electricity in the powersector in Brazil, and (C) biogas for cooking in households inChina. The results of Environmental Life-Cycle Assessment(E-LCA) show that for all these three scenarios, the use ofbiogas and pyrolysis gas contributes most to emissions mitigation,while the dewatering and drying processes carriedout on the sludge, contribute the most to the environmentalemissions. Addition of biochar to the soil, contributes significantlyto a reduction in global warming by sequesteringcarbon in the soil. Compared to scenarios B and C, ScenarioA, in which biogas substitutes gasoline in transportation, andheat from combusted pyrolysis gases is used for district heatingin Sweden, demonstrates the highest environmental performancefor all the evaluated impact categories.

  • 65.
    Mohammadi, Ali
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Sandberg, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Eskandari, Samieh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Dalgaard, Tommy
    Aarhus University, Denmark.
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Environmental analysis of producing biochar and energyrecovery from pulp and papermill biosludge2019In: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 23, no 5, p. 1039-1051Article in journal (Refereed)
    Abstract [en]

    Sweden is one of the largest exporters of pulp and paper products in the world. It follows that huge quantities of sludge rich in carbonaceous organic material and containing heavy metals are generated. This paper carried out a comparative environmental analysis of three different technologies, which can be adopted to produce biochar and recover energy from the biosludge, using landfilling as the reference case. These three thermochemical biosludge management systems—using incineration, pyrolysis, and hydrothermal carbonization (HTC)—were modeled using life cycle assessment (LCA). Heat generated in the incineration process (System A) was considered to be for captive consumption within the kraft pulp mills. It was assumed that the biochars—pyrochar and hydrochar—produced from pyrolysis (System B) and HTC (System C), respectively, were added to the forest soils. The LCA results show that all the alternative systems considerably improve the environmental performance of biosludge management, relative to landfilling. For all systems, there are net reductions in greenhouse gas emissions (–0.89, –1.43, and –1.13 tonnes CO2‐equivalent per tonne dry matter biosludge in Systems A, B, and C, respectively). System B resulted in the lowest potential eutrophication and terrestrial ecotoxicity impacts, whereas System C had the least acidification potential. The results of this analysis show that, from an environmental point of view, biochar soil amendment as an alternative method for handling pulp and paper mill biosludge is preferable to energy recovery. However, an optimal biochar system needs to factor in the social and economic contexts as well.

  • 66.
    Mohammadi, Ali
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Sandberg, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Eskandari, Samieh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Dalgaard, Tommy
    Aarhus University, Denmark.
    Joseph, Stephen
    University of New South Wales, Australia.
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Environmental performance of end-of-life handling alternatives for paper-and-pulp-mill sludge: Using digestate as a source of energy or for biochar production2019In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 182, p. 594-605Article in journal (Refereed)
    Abstract [en]

    This paper evaluates the environmental impacts of different alternatives for handling of sludge from paper and pulp mills in Sweden, using Life Cycle Assessment (LCA). The common practice of incineration of biosludge with energy recovery followed by landfilling of ash (System A) was compared with the alternative of digesting sludge anaerobically to produce biogas using different digestate residue management options. The digestate produced from anaerobic digestion (AD) was assumed to be incinerated for heat energy recovery in System B or pyrolyzed for biochar production in System C to be mixed with forest soils. The impact categories considered in this work are climate change, non-renewable energy use, mineral extraction, aquatic ecotoxicity, carcinogens and non-carcinogens. The LCA results demonstrate that the two proposed systems significantly reduce the environmental impacts of biosludge management relative to incineration. An 85% reduction in the aquatic ecotoxicity impact is achieved in System C, due to the reduced mobility of heavy metals in biochar relative to ash. System C, on the whole, outperformed the other two, leading the authors to the recommendation that the use of pulp and paper mill biosludge in biogas-biochar production systems is preferable to merely recovering energy from it.

  • 67. 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 Utility2013In: Journal - American Water Works Association, ISSN 0003-150X, E-ISSN 1551-8833, Vol. 105, no 3, p. 78-82Article in journal (Refereed)
    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.

  • 68.
    Pauliuk, Stefan
    et al.
    Norwegian Univ Sci & Technol, Ind Ecol Programme, N-7034 Trondheim, Norway.
    Govindarajan, Venkatesh
    Norwegian Univ Sci & Technol, Dept Hydraul & Environm Engn, N-7491 Trondheim, Norway.
    Brattebo, Helge
    Norway.
    Muller, Daniel B.
    Exploring urban mines: Pipe length and material stocks in urban water and wastewater networks2014In: Urban Water Journal, ISSN 1573-062X, Vol. 11, no 4, p. 274-283Article in journal (Refereed)
  • 69.
    Roghani, Bardia
    et al.
    University of Tehran, Iran.
    Tabesh, M
    University of Tehran, Iran.
    Amrollahi, M.S.
    University of Tehran, Iran.
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Estimation and Evaluation of Greenhouse Gas Emissions during the Life-Cycle of Wastewater Pipelines: Case study of Tehran, Iran2017In: Civil Engineering Infrastructures Journal, ISSN 2322-2093, Vol. 50, no 1, p. 191-206Article in journal (Refereed)
    Abstract [en]

    Climate change occasioned by the accumulation of greenhouse gases (GHGs) is now widely accepted as an issue which mankind needs to address. The starting point is necessarily the determination of all the sources of emissions during the life-cycles of the studied components. Post-calculation, the results ought to be presented to decision-makers in a clear manner so as to provide the basis on which corrective actions could be considered. This paper calculates the GHGs emissions during the life-cycle of wastewater pipelines and introduces a different approach to communicate information about GHGs released, to decision-makers. Different diameters of concrete and high-density polyethylene (HDPE) wastewater pipes are compared in a case study. Results show that the total CO

    2-equivalent (CO2-eq) emissions attributed to concrete pipes are greater than HDPE pipes. Hence, the equivalent bio-productive area of forest required to sequester the CO2 (the major GHG) and its corresponding costs will be greater for the former.

  • 70.
    Sandberg, Maria
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences (from 2013).
    Bengtsson, Simon
    Pawar, Sudhanshu
    Werker, Alan
    Willquist, Karin
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Novel biotechnical cascade concept to upgrade pulp and paper residues to hydrogen gas and polyhydroxyalkanoate (PHA)2018Conference paper (Other academic)
    Abstract [en]

    Pulp and paper mills use approximately 30 m3water per ton of produced paper. The process effluent has to be treated before being discharged. Mostly, the effluent is treated with aerobic biological processes using electricity for aeration, and added nutrients. The bio-sludge has low energy value and has to be disposed of. Here, we propose that effluent instead can be used as a feedstock for valuable products.

     

    Some of the bacteria in the bio-sludge can accumulatepolyhydroxyalkanoates(PHAs). PHA is a biopolymer that has a commercial value and is an important building block for the bio-plastics industry. For an efficient PHA production, volatile fatty acids (VFAs) are needed as the feedstock substrate. Process streams rich in sugars can be fermented by the thermophilic bacteria Caldicellulosiruptor, providing acetic acid and hydrogen gas. The acetic acid can then be used as substrate for PHA accumulation. 

     

    In a case study conducted at a large integrated pulp and paper mill (>700 000 ADt/y) in Sweden, the theoretical production volume of hydrogen gas and PHA were estimated. The calculations were based on measured process effluent volumes and water quality parameters, biological process yields from laboratory and pilot scale testing, and practical experience for the unit processes. The results indicated that 0.3 kg of hydrogen gas and 1.6 kg of PHA can be produced per ADt paper or board. The additional associated benefits are significant for the mill because the demand for nutrients and energy for aeration may, at the same time, decrease by 15 to 50 percent.

     

    By combining common biological treatment with fermentation and PHA accumulation, waste by-products can be transformed and upgraded to value-added hydrogen gas and PHA.  Such a secondary side-process integration helps to shift toward the circular bioeconomy. At the same time, less energy and nutrients are needed for the wastewater treatment.

  • 71.
    Sandberg, Maria
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Experimental study and analysis of the functional and life-cycle global warming effect of low-dose chemical pre-treatment of effluent from pulp and paper mills2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 174, p. 701-709Article in journal (Refereed)
    Abstract [en]

    Aeration, as a process in pulp and paper wastewater treatment, uses the greatest share of the energy. Therefore, if the energy efficiency of the treatment has to be improved, the focus must be on aeration. A Ivey finding from the trials conducted for this paper, with effluent from a paper and pulp mill, was that the oxygen transfer coefficient could be doubled and the chemical oxygen demand could be decreased by 25%, if the effluent was pre-treated with 30 mg/I of aluminium coagulant (equivalent to 9.4 tonnes per day of AVR to 20000 cubic metres of effluent). Decrease in oxygen requirement implies decreases in aeration energy use. Pulp and paper mill effluents are not as biodegradable as municipal sewage, and the improvement in oxygen transfer properties of the effluent will have a positive influence over a longer period of time in the biological treatment. If the sludge is digested anaerobically, pre-treatment will also result in doubling the potential for methane generation. A holistic analysis of modifications to processes entails a study of the economic and environmental consequences as well. While the economic aspect is beyond the scope of this paper, only the net global warming as an environmental impact category has been studied, by taking recourse to specific emission coefficients. Of the four dosages of ferric aluminium sulphate considered in this analysis, the net greenhouse gas emissions are the least - 426 kg carbon dioxide equivalent per day when the daily consumption is 9.4 tonnes.

  • 72.
    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.2010In: Urban Water Journal, ISSN 1573-062X, Vol. 7, no 6, p. 335-343Article in journal (Refereed)
    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.

  • 73.
    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 networks2010In: Journal of Infrastructure Systems, ISSN 1076-0342, E-ISSN 1943-555X, Vol. 16, no 2, p. 112-121Article in journal (Refereed)
    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.

  • 74.
    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)2008In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 58, no 12, p. 2279-2293Article in journal (Refereed)
    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.

  • 75.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    The influence of packaging attributes on recycling and food waste behaviour – An environmental comparison of two packaging alternatives2016In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 137, p. 895-902Article in journal (Refereed)
    Abstract [en]

    This paper analyses how user behaviour influences the environmental comparison of two different packages for minced meat - a lightweight tube and a tray. The direct and indirect environmental effects are evaluated using simplified LCA. A number of packaging attributes with regard to food waste and recycling behaviour are analysed for the packages, and then used for the scenario calculations. The results show that the tube is the superior environmental alternative when only the direct effects are considered. When indirect effects and user behaviour are included in the comparison, the tray is the better alternative due to higher recycling rates and, most importantly, less food waste during the process of emptying. However, the environmental impacts due to the food waste in the tube may be compensated for, if the longer shelf-life of the tube results in lower wastage in the households. It is concluded that indirect environmental effects and user behaviour should be included in environmental assessments of packaging to obtain meaningful results.

  • 76.
    Zappine, M
    et al.
    Politecnico di Torino, Italy.
    Fiore, S
    Politecnico di Torino, Italy.
    Govindarajan, Venkatesh
    Department of Hydraulic and Environmental Engineering, NTNU, Trondheim, Norway.
    Brattebö, L
    V.
    Meucci, L
    Research Center, Torino, Italy.
    Life-cycle energy and greenhouse gas emissions within the Turin Metropolitan Urban Water Cycle2014In: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 89, no 1, p. 1382-1389Article in journal (Refereed)
12 51 - 76 of 76
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