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Water and Energy: Threats and Opportunities

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... Water pollution by textile dyes, heavy metals, and plastic waste is the most massive global issue [1]. Also, speedy manufacturing and increasing population growth have created a significant energy crisis and an environmental emergency [2,3]. Presently, 1.2 billion people lack drinking water sources. ...
... 60 % of AB-92 was removed within 10 min and slowly increased till equilibrium was achieved after 120 min, as indicated in Figure S6. The higher q t of G-MIL-101(Cr)@R for AB-92 in the first stage can be explained by the electrostatic interaction that might be formed between the SO 3 2− groups of AB-92 dye and the unsaturated Cr 3+ sites of G-MIL-101(Cr)@R. Besides, AB-92 molecules rapidly fill the G-MIL-101 (Cr)@R pores, so the G-MIL-101(Cr)@R remaining pore sites are slowly used up. ...
... As shown in Fig. 6c, the removal efficiency drops slightly from 100 % to 70 % after 6 cycles. It might be because some unsaturated chromium sites in G-MIL-101(Cr)@R can electrostatically interact with the SO 3 2− groups of AB-92 dye. Besides, all G-MIL-101(Cr)@R pores were filled by dye molecules. ...
Article
MIL-101(Cr) MOF (MIL-Materials of Institute Lavoisier; Metal-organic framework) as an adsorbent has great application in water treatment because of its high stability against air, temperature, and chemicals. Herein, we develop a novel value-added, sustainable, and eco-friendly green method to prepare MIL-101(Cr) hydrothermally based on organic and inorganic waste recycling (G-MIL-101(Cr)@R) without hydrofluoric acid (HF) addition. Several characterization techniques suggest that G-MIL-101(Cr)@R was successfully synthesized. Then, it was used as an adsorbent for acid blue 92 dye (AB-92) as a model of anionic dyes. The adsorption parameters were studied, such as adsorbent dose, contact time, pH, dye concentration, temperature, salinity, and dye selectivity. The results showed that the adsorption of AB-92 is a monolayer according to the Langmuir isotherm with a q max of 2176 mg/g. Adsorption kinetics follow the pseudo second-order model (R 2 = 0.99), occurring in three steps according to the intra-particle diffusion kinetic model. The adsorption of AB-92 over G-MIL-101(Cr)@R is spontaneous and exothermic. The adsorption mechanism is mainly defined by electrostatic interactions. G-MIL-101(Cr)@R can adsorb the anionic dyes more efficiently than cationic dyes. It could also be reused for up to five cycles with an uptake efficiency of not less than 80 % without any change in its structure. Finally, G-MIL-101(Cr) @R is considered a superior adsorbent for anionic dyes. So, it will pave the way for developing MIL-101(Cr), based on organic and inorganic waste recycling, as an efficient adsorbent for removing organic dyes from wastewater.
... Per exemple, l'aigua és necessària per la indústria extractiva (per produir fuels com carbó, urani, petroli i gas), pera la producció dels biocombustibles (blat de moro, sucre de canya) i també és crucial per al moviment de les turbines de les centrals hidroelèctriques i per l'escalfament de l'aigua (vapor) de les centrals tèrmiques i la refrigeració. Segons Olsson (2012) es calcula que entre un 1% i 18% de l'energia elèctrica de les ciutats és consumida en el transport de l'aigua i la gestió de les aigües residuals. És possible que en el nostre país, aquest consum sigui superior atès que en períodes de sequera cal incrementar l'activitat de les plantes dessalinitzadores. ...
... Figura 1: Relació del consum d'energia en el cicle urbà de l'aigua (Adaptació d 'Olsson, 2012) Figura 2: Gràfics extrets del Informe The united Nations world water report, que expressen la demanda global d'aigua (a dalt esquerra), l'energia necessària per a proveïr d'un m 3 d'aigua (a baix esquerra) i el Consum d'aigua per a la producció de combustible (dreta). EDUCAR PER UNA NOVA CULTURA AMBIENTAL DE L'AIGUA Per abordar des de l'àmbit educatiu la complexitat d'aquesta temàtica, aquest article presenta tres propostes de mapes de progressió sobre l'aigua que poden ajudar a organitzar situacions d'aprenentatge que afavoreixen una millor comprensió. ...
... • Idea 1: Reconèixer el nexe existent entre el consum d'aigua i de l'energia. Els experts (Olsson, 2012) alerten que cal energia per disposar d'aigua apta pel consum humà i ens cal aigua per extreure els combustibles fòssils necessaris per a la producció energètica. En canvi, a la recerca s'ha comprovat que l'alumnat no incorpora la variable energia en les seves argumentacions ni en les representacions del cicle de l'aigua (no dibuixen instal·lacions elèctriques que permetin el funcionament de les depuradores o potabilitzadores així com tampoc, tenen en compte de dibuixar els dipòsits d'emmagatzemament de l'aigua, ni la ubicació d'aquestes instal·lacions per afavorir que l'aigua circuli per gravetat i estalviar així energia). ...
Article
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L’emergència climàtica ja té uns efectes importants sobre els recursos hídrics del nostre territori fet que es fa urgent i necessari educar a favor d’una nova cultura ambiental de l’aigua. L’article presenta tres mapes de progressió que poden ajudar a professorat i educadors/es ambientals a organitzar situacions d’ensenyament-aprenentatge que promouen un aprenentatge més profund. Els mapes, que s’han elaborat a partir d’una recerca educativa, s’organitzen a partir de preguntes ordenades segons el nivell de complexitat i identifiquen les idees-claus que permeten donar resposta a cada pregunta així com expressions que el professorat pot utilitzar per fer-les més comprensibles. També, s’hi destaquen els continguts més complexes o que afavoreixen la visibilització dels vincles entre l’aigua i l’energia.
... Issues of connectivity and comparability between different infrastructure sectors have, however, received surprisingly little attention in policy and research circles. Where addressed at all, the interest of infrastructure managers tends to be limited to ways of improving the efficiency or meeting regulatory requirements of a specific sector, such as how to save energy in treating wastewater or how to lower the temperature of cooling water (Olsson 2012). Initiatives to explore innovative ways of interlinking different infrastructure systems for multiple societal benefits are, by contrast, rare (Hansman et al. 2006, Broto andBulkeley 2013). ...
... The water-energy nexus Recent years have witnessed transformations in both the water and the energy sector which have been orientated largely towards security of supply and environmental sustainability. Water scarcity on the one hand and increasing energy consumption coupled with concerns over climate change on the other appear to be the most urgent problems and principal drivers of change for the two sectors respectively (Olsson 2012). In terms of physical processes, energy and water are closely connected: "Indeed, water mixes with just about every form of energy that human society has hitherto harnessed" (Williams et al. 2014, p. 3). ...
... Pumping, processing, distribution and treatment of both freshwater and wastewater consume considerable amounts of energy (King et al. 2013). Conversely, the energy sector has one of the highest levels of water use of any sector of the economy (Carter 2010, Olsson 2012. The extraction and refining of fuels as well the generation and distribution of electricity from both traditional and renewable energy sources can require vast amounts of water, though this is disputed in the literature. ...
Article
Issues of connectivity between different infrastructure sectors have received surprisingly little attention in recent research. Despite huge interest in issues of sectoral integration surrounding the water–energy nexus, researchers have rarely considered what this might mean for the coupling of infrastructure systems for water/wastewater and energy services. Consequently, the implications of greater connectivity for the governance and socio-spatial constitution of infrastructures are largely unexplored. This paper addresses this research gap with a case study of an attempt to use treated wastewater to produce biomass for energy on degraded land in the Berlin-Brandenburg region of Germany. It takes water reuse for energy crop production as an exemplar of work at the water–energy nexus in order to explore the institutional, spatial and physical dimensions involved in connecting two infrastructure systems to this end. It argues that cross-sectoral integration reaches far beyond issues of technological compatibility, revealing often hidden but crucial differences in the institutional and spatial configuration of energy and wastewater systems. On the basis of a comparative analysis of the institutional arrangements of the region’s wastewater and energy systems together with an empirical study of initiatives to use treated wastewater to grow energy crops the paper draws conclusions, firstly, on the potential and limitations of this particular exemplar and, secondly, on the broader implications of the case for understanding institutional challenges of cross-sectoral connectivity on the one hand and prospects for reconfiguring infrastructural relations between cities and rural areas on the other.
... Proper operation of existing water systems is widely recognized as one of the most important and cost-effective ways to improve water use efficiency and reduce stresses caused by rapid population growth and socioeconomic development (Ehsani et al., 2017;Giuliani et al., 2016a;Olsson, 2015). Water reservoirs generally serve multiple and competing purposes, including flood control, irrigation, power generation, navigation, and river ecosystem maintenance, but limited water resources make it impossible to fully and simultaneously satisfy all of these water users (Billington and Jackson, 2006;Groenfeldt, 2019). ...
... Water reservoirs generally serve multiple and competing purposes, including flood control, irrigation, power generation, navigation, and river ecosystem maintenance, but limited water resources make it impossible to fully and simultaneously satisfy all of these water users (Billington and Jackson, 2006;Groenfeldt, 2019). At the same time, growing energy and food demands are putting additional pressure on these systems and are exacerbating conflicts (Ehsani et al., 2017;Giuliani et al., 2016a;Olsson, 2015), which are often related to emerging adverse social and environmental consequences caused by water infrastructure (Graham et al., 2020;Poff and Schmidt, 2016;Sabo et al., 2017;Schmitt et al., 2018) and to water security (D'Odorico et al., 2018;Liu et al., 2018;Scanlon et al., 2017). These challenges represent a well-established topic in the water systems analysis community since the Harvard Water Program (Maass et al., 1962), promoting the idea of adopting a posteriori decisionmaking based on trade-off analysis between competing objectives (Cohon and Marks, 1975;Maier et al., 2014;Nicklow et al., 2010;Reed et al., 2013). ...
Article
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Participatory decision-making is a well-established approach to address the increasing pressure on water systems induced by growing multi-sectoral demands and increased competition among different water users. However, most existing approaches search for system-wise efficient solutions and do not quantify their distributional effect among the stakeholders. In this work, we investigate how to operationalize equity principles to design improved water systems operations that better balance efficiency and justice. More specifically, we explore the extent to which the inclusion of equity principles reshapes the space of efficient solutions. Numerical experiments are conducted on the Lake Como system, Italy, operated primarily for flood control and irrigation water supply while also providing recreation and river ecosystem services. Our results show how incorporating equity considerations into the design of water system operations enriches the solution space by generating more compromise solutions than those obtained using a traditional multi-objective optimization. Moreover, we find that including equity in the operating policy design can indirectly improve the performance of marginalized sectors, such as recreation and ecosystem, which are not explicitly considered by the current lake operation. Lastly, we illustrate how the aggregation of multi-sectoral interests into an equity index strongly shapes our results. Thus, eliciting the preference structure of stakeholders and policymakers becomes paramount for the identification of a fair balance across competing interests. This work bridges the gap between multi-objective optimization approaches and equity-informed decision-making for real-world water resources planning and management, providing an effective tool to promote efficient and equitable policies.
... The economic growth of society and mankind much depend on water as a vital input for sustainability (Markantonis et al. 2019). However, water has been, and is still a source of conflict between people, regions and nations (Olsson 2015). For example, Ethiopia and Egypt have conflict over River Nile water for decades now. ...
... Energy is a fundamental condition for a decent life and is needed to process and make drinking water available and at the same time treat wastewater. The fundamental differences between water and energy are that energy can be renewed, while water resources are not (Olsson 2015). Energy for heating in homes, especially in urban areas, is very crucial as it can be used for pumping, filtering and heating swimming pools (Kenway et al. 2008). ...
Article
The concept of water-energy nexus has gained global attention since the 2011 Bonn conference in Germany. Water-energy nexus thinking is critical because it supports various life forms on Earth, and its understanding can help in achieving sustainable development goals. In the present day, water and energy are closely intertwined, support and depend on each other for sustainable development in agriculture, urban settings and the industrial sector. Although the water-energy nexus still faces challenges of universal understanding, its adoption within the scientific community has been impressive over the past decades. Over 120 studies were reviewed in line with their aims, scopes, methods and limitations. About 23 case studies were summarized according to their title, objectives and major conclusions, while 21 case studies were cross-examined based on water-energy nexus studies within the urban systems. Models and methods use in water-energy nexus research were also reviewed with emphasis on their strength and weaknesses. The undisputable challenge within the water-energy nexus approach was found to be understanding, as concluded by almost all literature reviewed. Understanding the nexus approach and patterns is a huge limitation for the targeted audience, especially decision and policymakers. Bridging this knowledge gap between water-energy nexus scholars and decision or policymakers could lead to a significant breakthrough in the nexus arena. Another challenge faced by the water-energy nexus approach is the fact that though there are many methods currently employed, yet there is no single agreed or universally acceptable framework that could be used for the water-energy nexus studies globally. For a better understanding of the nexus thinking, more work in relation to understanding, framework and methods needs to be done in the water-energy nexus domain using a holistic approach. It is recommended that further analysis of the interlink ages of water-energy nexus can help mitigate the problem of understanding the system and hence support the sustainable development goals drive.
... According to the US Environmental Protection Agency, 3-4% of total electricity use in the US is consumed by drinking water and wastewater systems [5,6]. A relationship between energy and water, the "water-energy nexus", has been the focus of attention worldwide due to climate change, population increase and urbanization [7,8]. While there is a high water demand for power generation, WWTP consume large amounts of electricity in most countries [9]. ...
... Details and assumed values for various parameters in Equation (8) are seen in Table 2. ...
Article
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The water–energy nexus (WEN) has become increasingly important due to differences in supply and demand of both commodities. At the center of the WEN is wastewater treatment plants (WWTP), which can consume a significant portion of total electricity usage in many developed countries. In this study, a novel multigeneration energy system has been developed to provide an energetically self-sufficient WWTP. This system consists of four major subsystems: an activated sludge process, an anerobic digester, a gas power (Brayton) cycle, and a steam power (Rankine) cycle. Furthermore, a novel secondary compressor has been attached to the Brayton cycle to power aeration in the activated sludge system in order to increase the efficiency of the overall system. The energy and exergy efficiencies have been investigated by varying several parameters in both WWTP and power cycles. The effect of these parameters (biological oxygen demand, dissolved oxygen level, turbine inlet temperature, compression ratio and preheater temperature) on the self-efficiency has also been investigated. It was found here that up to 109% of the wastewater treatment energy demand can be produced using the proposed system. The turbine inlet temperature of the Brayton cycle has the largest effect on self-sufficiency of the system. Energy and exergy efficiencies of the overall system varied from 35.7% to 46.0% and from 30.6% to 33.55%, respectively.
... The energy in the WW largely comes from domestic hot water. According to several international studies, the energy use in the urban water cycle adds up to 10% or more of the total national energy use (Olsson 2012). Out of this only about 10% (corresponding to 1% of the total energy use) is used for withdrawal, treatment and distribution of tap water and collection, treatment and discharge of wastewater. ...
... Out of this only about 10% (corresponding to 1% of the total energy use) is used for withdrawal, treatment and distribution of tap water and collection, treatment and discharge of wastewater. The remaining partthe absolute majorityis used by the customers mainly for heating tap water for showers, dishwashers and laundry (Olsson 2012). The Swedish Energy Agency (2009) has estimated the heat requirement in households for domestic hot water (DHW) to be 1,150 kWh/cap/yr. ...
Article
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Wastewater heat recovery upstream of wastewater treatment plants (WWTPs) poses a risk to treatment performance, i.e. the biological processes. In order to perform a sustainability analysis, a detailed prediction of the temperature dynamics over the WWTP is needed. A comprehensive set of heat balance equations was included in a plant-wide process model and validated for the WWTP in Linköping, Sweden, to predict temperature variations over the whole year in a temperate climate. A detailed model for the excess heat generation of biological processes was developed. The annual average temperature change from influent to effluent was 0.78 °C with clear seasonal variations; 45% of the temperature change arises from processes other than the activated sludge unit. Hence, plant-wide energy modelling was necessary to predict in-tank temperature in the biological treatment steps. The energy processes with the largest energy gains were solar radiation and biological processes, while the largest losses were from conduction, convection and atmospheric radiation. Tanks with large surface areas have a significant impact on the heat balance regardless of biological processes. Simulating a 3 °C lower influent temperature, the temperature in the activated sludge unit dropped by 2.8 °C, which had a negative impact on nitrogen removal. HIGHLIGHTS The annual average temperature change (ΔT) was +0.78 °C from influent to effluent.; Biological processes had the largest energy contribution.; 45% of ΔT arises from other processes than activated sludge. Hence, plant-wide energy modelling is necessary.; ΔT shows strong seasonal variation in colder climates. Dynamic parameters are necessary.; Tanks with large open surface areas have significant impact on the heat balance.;
... The rapid industrial growth has increased the demand for oil exploration, transportation and industrial use of petroleum oil in several ways resulting in the exponential increase in wastewater that contaminated with oil. Contamination of natural water bodies by petroleum and non-petroleum oils, such as vegetable oils and animal fats pose threats to public health and the environment as they have toxic properties and produce harmful physical effects, i.e. oil spills may harm sea grasses and kelp beds and also, can harm birds and mammals by physical contacts of toxic substances [1,2]. Skimming, coagulation-flocculation, gravity separation, adsorption and biological degradation methods etc., are the conventional methods that have been used for decades for the removal of oil from the oil-contaminated wastewater [3][4][5][6]. ...
... The higher water contact angle as well as the fast oil wetting properties of filter B additionally supports the superoleophilicity of filters B than the filters A and C. The superior oil-water separation properties of filter B can be explained as follows; The oil-water separation performance of a filter strongly depends on surface energy and surface roughness of the filtering material which, will lead either to repel water or attract oil vise-versa [59][60][61]. According to the Wenzel's model, if a surface is wetted by a liquid satisfactorily, the wetting of the surface by the liquid will be enhanced with the increase of the roughness and if the surface repel the liquid, it will enhance the repelling of the liquid [2]. Different fabrication methods employed in this investigation was intend to have different surface energy, surface roughness and the adhesion to the SS. ...
Article
Special wetting polystyrene (PS) based superhydrophobic material has been investigated as a potential cost-effective and efficient oil-water separation membrane to remediate the oil spills. However, superhydrophobic properties of polystyrene based materials are susceptible to harsh physical or chemical conditions and their superhydrophobic properties can be diminished easily. To address the stability of polystyrene based superhydrophobic membranes, polystyrene was cross-linked with the acrylic acid (AA) either by ex-situ or in-situ polymerization on the TiO2 nanoparticles. Membranes fabricated either by ex-situ or in-situ polymerization of styrene-acrylic acid on the TiO2 nanoparticles exhibited enhanced oleophilic properties having the oil contact angles of ~ 0o. The water contact angles of different membranes varied in the range 141 ~155o demonstrating the variation of hydrophobic properties of different membranes fabricated by controlling the styrene-acrylic acid co-polymer coating method. Membranes fabricated with co-polymerized PS-polyacrylic acid(PAA)/TiO2 NPs can be used to separate for both highly viscous and light oils having exceptional oil-water separation efficiencies of ~99%. The in-situ co-polymerized PS-PAA/TiO2(NP) membranes separate high and low density oils from water with a separation efficiency of over ~99% with a flux of ~50000-60000 L m-2 h-1 under gravity driven process and a flux of ~7500-9000 L m-2 h-1 under antigravity driven process due to excellent oil-wetting properties. It was demonstrated that the oil–water separation efficiency, reusability, durability and hydrophobicity of the styrene-acrylic acid co-polymer coated TiO2 membranes can be enhanced by using appropriate membrane fabrication methods.
... Con la expansión urbana y el crecimiento económico y poblacional, los conflictos por la demanda de recursos como el agua, la energía y los alimentos han aumentado en muchas partes del mundo, tanto en áreas industrializadas como en desarrollo. (Olsson 2012). El agua, siendo fundamental para el desarrollo, representa uno de los mayores desafíos que enfrenta Latinoamérica para lograr un desarrollo sostenible en áreas urbanas y rurales. ...
Article
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La pérdida de especies vegetales es un fenómeno alarmante que tiene implicaciones significativas para la diversidad global y la persistencia de los ecosistemas. Este artículo revisa los principales orígenes del detrimento de especies de flora, analizando factores como la destrucción del hábitat, el cambio climático, la contaminación, la introducción de especies invasoras, y la sobreexplotación de recursos. Palabras clave: Erosión, Flora, Prospección, Diversidad, Conservación.
... However, since the year 2006, the governments have developed a plan that is expected to see the country increase its production of energy from renewable sources from less than 1% to 6% in the near future. This would include construction of several plants to tap energy from the sun and the wind (Olsson, 2015). This would comprise the construction of several wind farms expected to generate a total of 750 MW, PV centre should generate 50MW and solar heaters which should generate 100 MW. ...
Article
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In recent years, the energy production by wind turbines has been increasing, because its production is environmentally friendly; therefore, the technology developed for the production of energy through wind turbines brings great challenges in the investigation. The use of wind energy worldwide has overgrown in recent years to reduce greenhouse gas emissions. Wind power is free, but the installation and maintenance of wind turbines still remain costly. Wind vitality is the second biggest wellspring of sustainable power source after hydropower. However, it has not yet accomplished full matrix equality with fossil vitality sources. In this work experimental design of small HAWT for home electricity has been designed and analysed in the laboratory at the Libyan Academy for Postgraduate Studies, Al-Bayda-Libya. Experimental work was used in this paper to evaluate the wind energy data in Al-Bayda, East of Libya. The field tests and measurements proved that the present turbine is efficient and has long lifetime and needs minimum maintenance. Wind turbines convert wind energy into electricity. The efficiency of this conversion is measured by comparing the incoming winds speed and the output power. From the experimental work it was found that the present turbine is efficient, easy to construct and assembly, has long lifetime and needs minimum maintenance, suitable for different sites such as urban, suburban, rural, and sea coast and the output power of the turbine covers the consumption of many electric devices.
... Although water is said to be naturally abundant in rivers, lakes and underground reservoirs, constituting about 70 % of the earth, research has shown that only 2.5 -3 % of this is fresh, out of which only 0.4 % is drinkable while about 1.6 % is polar ice caps and glacier (Benson, 2018). In recent times, water purification processes have become of important, and despite technological advancements, about 14.7 % of the earth's population still lack access to clean water, a crisis which has led to ground water overdraft, diminished agricultural yields, regional conflicts over scarce water resources, inadequate access to water for sanitation and waste disposal amongst others (Olsson, 2015;World Health Organization, 2016). ...
Article
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An experimental study on the effects of beeswax incorporated in the construction of the absorber for a solar still was conducted. As part of the study, two solar stills of the same geometry were constructed with the same water depth and volume. The one without a phase change material (PCM) was used as the control still, while the other with beeswax as a phase change material laid at the bottom of its basin to serve as an absorber was used as the experimental still. The experiments were conducted in the thermodynamic laboratory of JS Tarka University, Makurdi, Nigeria, between 10.00 am and 5.00 pm for two weeks. 16 litres of water were used for each still, corresponding to 100 mm depth. The stills were kept side by side and exposed to sunshine from 10.00 am to 5.00 pm for three days. Temperatures of the water at inlet and in the still were measured. HT-9815 digital thermocouple was used to determine the temperature of water in the basin and that of the inner glass cover. SM206 solar power meter was used to measure the amount of solar energy incident on the still’s collector. The results showed that the still with beeswax as phase change material (experimental still) has an improved thermal efficiency enhancement of 109.30% as compared to the still without a phase change material with a thermal efficiency enhancement of 86.1%. This implies that beeswax is a good phase change material for solar stills, and the use of beeswax should be encouraged as it is non-toxic and organic.
... Over time, these networked systems began to develop interactions between themselves in what is now called systems-of-systems [2]- [7]. The "smart grid" [8], the energywater nexus [9], [10], the electrification of transport [11]- [15], are all good examples where one network system has fused with another to form a new and much more capable system. This trend is only set to continue. ...
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In the 20th century, individual technology products like the generator, telephone, and automobile were connected to form many of the large-scale, complex, infrastructure networks we know today: the power grid, the communication infrastructure, and the transportation system. Progressively, these networked systems began interacting, forming what is now known as systems-of-systems. Because the component systems in the system-of-systems differ, modeling and analysis techniques with primitives applicable across multiple domains or disciplines are needed. For example, linear graphs and bond graphs have been used extensively in the electrical engineering, mechanical engineering, and mechatronic fields to design and analyze a wide variety of engineering systems. In contrast, hetero-functional graph theory (HFGT) has emerged to study many complex engineering systems and systems-of-systems (e.g. electric power, potable water, wastewater, natural gas, oil, coal, multi-modal transportation, mass-customized production, and personalized healthcare delivery systems). This paper seeks to relate hetero-functional graphs to linear graphs and bond graphs and demonstrate that the former is a generalization of the latter two. The contribution is relayed in three stages. First, the three modeling techniques are compared conceptually. Next, these techniques are contrasted on six example systems: (a) an electrical system, (b) a translational mechanical system, (c) a rotational mechanical system, (d) a fluidic system, (e) a thermal system, and (f) a multi-energy (electro-mechanical) system. Finally, this paper proves mathematically that hetero-functional graphs are a formal generalization of both linear graphs and bond graphs.
... In RO, high voltage pushes water through a semipermeable membrane, while EDR uses voltage to move salts through an ion exchange membrane [29]. MVC mechanically compresses steam to promote water and salt separation [30]. New entrants in the non-thermal field, such as crystallization and ion exchange-offer alternative routes to salt removal, although they are not yet widely available [31]. ...
... The agricultural sector and food industries pollute water and result in greywater. Moreover, food loss/waste (FLW) leads to the depletion of water resources (Olsson, 2015;Porat et al., 2018). The recycling and reuse of greywater for irrigation can effectively contribute to environmental sustainability (Kisser et al., 2020). ...
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Sustainable management of food systems is not possible without considering the entirety of the supply chain. The limitation of water and energy resources, the pressure of population growth, climate change and numerous environmental challenges have turned the sustainability of the food supply chain (FSC) into a major global concern. This article is trying to provide a comprehensive and appropriate index to evaluate the sustainability of the FSC by a systematic literature review. For this, 96 articles were reviewed and divided into four categories according to the purpose of the study: water and FSC, energy and FSC, water and energy in the FSC, and climate (environment) and FSC. Furthermore, the interconnections between climate change and the FSC were identified, and their effects on the categorized components within the FSC were examined. The integration of components in four categories and the combination of climate change impacts on them resulted in an exciting prospect and a comprehensive index called the Water-Energy-Food-Environment-Climate change nexus (WEFEC) index to evaluate the sustainability of the FSC. Finally, proposed nexus could direct future studies and help planners make efficient actions in the sustainable FSCs.
... A number of proposals have been made taking advantage of the potential energy provided by the elevation differential of the Dead Sea, which at 1,335 feet below sea level is the lowest point on Earth. (Olsson, 2015). In the early 1990s ...
Article
Water is the lifeblood of all human and natural systems. Although most regions of the world have abundant water resources, availability of drinking water is inadequate in many parts of the world. Current and projected water shortages are nowhere as acute as in the arid countries of the Middle East. While battles have been fought over water allocation in many countries, the greatest potential for a conflict over water is perhaps in the Middle East, where water resources are limited and political tension is high. Water is just one of the issues that may widen the gulf between countries. Cooperation to solve water problems is possible, though difficult. Indeed, joint action on water has the potential to lead to even greater co-operation in the wider political arena. Mutually beneficial, “win – win” solutions are preferable to conflict or stalemate. Conversely, arrangements not arrived at to fairly allocate one of life’s most important necessities can only perpetuate conflict. The most pressing environmental problem in the Middle East concerns the ownership, management and useof scarce water resources. Water has frequently been the cause of regional conflicts. Much of the struggle between Israel and its Arab neighbours revolves around the water issues. Indeed, the history of relationship between Israel, Syria, and Jordan for the past 50 years can be viewed as a fight for water. A long-term settlement between Israel and its neighbours will depend as much on the fair allocation of water as of land. Nearby, Egypt fears an appropriation of the Niles waters, on which 60 million of its people are entirely dependent, by the upstream countries of Sudan and Ethiopia. Water problem is linked with other problems of the Middle East. The dispute between Iranand Iraq over Shatt-al-Arab, for example, has its origins in boundary conflicts that go back in history. Arguments between Turkey and Syria over water from the River Euphrates are often linked to Syrian support to the Marxist Kurdistan Workers’ Party (PKK) that seeks independence for the Turkish Kurdistan region. Iraqi-Syrian water disagreements have both masked and resulted from military and political ambitions.
... When emissions from water use in industrial and commercial premises are included approximately 7% of Australia's GHG emissions are accounted for. Countries in western Europe and North America have similar profiles (Olsson, 2015). Consequently, by focusing solely on managing their Scope 1 and 2 emissions, water utilities influence only 1% of total GHG emissions, or about 10% of their total potential. ...
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The water sector could play a major role towards a Net Zero greenhouse gas (GHG) future if Scope 3 emissions were embraced and operationalised. Significant opportunities and challenges exist in tackling Scope 3 emissions including those associated with customer hot water use. Present GHG emission reduction practices predominantly focus on Scope 1 "within utility" and Scope 2 "purchased energy" emissions. In the urban water cycle, Scope 3 "indirect" emissions dominate, and water use is only one example of Scope 3 emissions. Over 90% of all water cycle GHG emissions can be attributed to water use in residential, industrial and commercial premises, collectively some 7% of global GHG emissions. One possibility is for water utilities to actively support efficient hot water use such as new ultra-low flow shower heads. Scope 3 opportunities also offer a range of cost-effective emissions-reduction opportunities, particularly when the wider perspective of "community value" is considered and not just a "business financial perspective". Hot water efficiency is additionally essential to Net Zero carbon futures, even with decarbonised grids, because most major Net Zero roadmaps require energy efficiency gains. Scientific and management advance needed includes: accounting methodologies, clear roles, collaboration, new business models, and clear definitions. The water sector has the opportunity to play a significant role in achieving Net Zero cities. The decision how much is yet to be made.
... To complicate the matter further, given that desalination will invariably contribute towards an increase in the levels of embedded energy in a region's water supply and that energy represents the single largest variable cost in operating a desalting plant, the mobilisation of seawater for municipal supply is likely to intensify the water-energy nexus. Deepening the interdependencies between water, energy and climate through desalination may further confound the manifold tensions between the two sectors and give rise to negative trade-offs (Kurian and Ardakanian, 2015;Olsson, 2015). This could hold a twofold implication. ...
... While our current infrastructure assets are increasingly under pressure from higher population demands, growing environmental and economic requirements and stronger climate variations, we are not proactively and constructively incorporating novel, alternative solutions at a rate that would help to alleviate these challenges. With the growing push towards a circular economy, including more sustainable energy and resource management solutions, the opportunities and benefits of a more inclusive and integrated approach are becoming even more compelling (Olsson 2015;Estévez et al., 2022). ...
Article
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Numerous innovative decentralised urban water solutions have been described over many years, yet their application in practice is still not common at all. While many proposed solutions may have some techno-economic advantages over current systems, the real reasons for the slow uptake have more to do with system-wide inertia and technology ‘lock-in’ where existing solutions are preferred for simplicity and familiarity. A key factor is also the inadequate assessments in project decision making processes that should consider all relevant social, environmental and economic benefits and values. This paper highlights some key barriers and how to address them in a more holistic way. It also identifies opportunities where more integrated, hybrid solutions could offer significant benefits over current technologies. It calls on all key partners in this sector to foster broad and strong collaborations, and on water service providers to be empowered to take an inclusive leadership role in creating such innovative solutions that help address our growing challenges driven by rapid urbanisation and climate change.
... Energy is becoming a limited resource due to its high and continuous growing demand and the necessity of reducing the use of fossil fuels. Even if solar photovoltaics and wind power generation are growing rapidly, water consumption for electricity generation is expected to grow constantly by a factor three, reaching 225,000 billion liters by the end of the 21st century as presented by several scenario studies (Davies et al., 2013;GEA, 2012;Olsson, 2012). Davies et al. (2013) expects for example a twofold increase of the water consumption in the hydropower sector by 2095 globally. ...
Article
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Sustainable water management should consider climate change effects to ensure its future availability. Hydrological modeling is a supportive tool for this analysis, which has been used in this work to assess the climate change impacts on the water resources of three basins under Mediterranean climate (Ompólveda and Salado River basins, in Spain, and Guadalupe River basin, in Mexico). The outcomes of previous climate change scenarios simulation addressed with the Soil and Water Assessment Tool (SWAT) have been compiled, evaluating the impacts on the water balance, and focusing on the streamflow components. The potential implications of these effects on energy production have been discussed. The results point to a streamflow reduction by the end of the century around 50%–60% in the worst scenarios, with varying effects for each of the streamflow components. In the Spanish catchments, where groundwater contribution dominates in baseline conditions, a noticeable decrease of this component is expected (up to -74%), becoming lateral flow the main streamflow component. In the Mexican basin, lateral flow, which is already predominant (69%), will experience the largest absolute decrease, but the highest relative decrease might be experienced by groundwater flow, up to -92%. Absolute variations in the surface component are small and the different ways to simulate the climate change scenarios might hinder their interpretation. This work shows that water resources will be even more scarce in these regions, being especially worrying the groundwater component reduction, which currently maintains the streamflow during dry periods. This situation would limit energy production both from sources that directly use water, such as hydropower, and others that require water for cooling. Higher atmospheric and water temperatures will increase demands for irrigation and for cooling systems. Therefore, competition for water will rise among key sectors, and an accurate planning considering these factors must be a priority.
... Specifically, hydropower generation in traditional WDNs can be attained by exploiting localized excess water pressures which are typically damped. Different strategies exist for this purpose, as well as to reduce energy consumptions [11] and water leakages [12], such as the application of pressure control through pressure reducing valves (PRVs) or within pressure break tanks [13][14][15][16]. Specifically, to reduce leakages and avoid damages to appliances, a potential energy is dissipated into heat when PRVs are used, although this could be converted into electric power using hydraulic turbines. ...
Article
A novel approach is investigated, based on an integrated solution aiming at exploiting the energy harvestable from both drinking water reaching a municipality (or district) and wastewater flowing out from households. Global costs are also analyzed under several macroeconomic scenarios. A first experimental set was carried out using a supply system, where the mechanical power was generated using a pump as turbine (PAT). The biogas production, especially from black water discharged in a separated sewage system, was analyzed during a second set, to evaluate the anaerobic valorization of carbon sources. Several scenarios were built for small-scale urban applications, varying parameters like population and macroeconomic conditions. The produced energy changes among the scenarios: the PAT is optimized when hydraulic regulation is used, while the anaerobic digestion is optimized for decentralized system coupled to toilet operation without urine separation. Differences in energy production and costs exist between the analyzed technologies, the PAT requiring small investments for a small production, the anaerobic digestion requiring high costs for a large production. Hence, the application to urban contexts depends on the local means/needs and the size of the exploitable territory. The work also draws a potential methodology for urban planning in developing or developed countries.
... The national annual report of energy is used for the number of electric pumps and the electricity demand of each pump per year in the basin. To calculate the energy demand for treatment of 1 m 3 of wastewater treatment, values from Olsson (2012) are considered. It is assumed that 0.9 GWh m À3 electricity is required for advanced levels of wastewater treatment (C, N, and P removal, heavy metal removal, etc.). ...
... The series of books focusing on 'Water and Energy' (Olsson, 2012a(Olsson, , 2015(Olsson, , 2019 teaches us that 'the global energy challenge depends on water'. Adding food to water and energy, he provides us with examples on how energy security, water security and food security are interlinked. ...
Chapter
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Professor Gustaf Olsson has devoted countless hours over many years to Water Science and Technology, Water Supply and Water Practice and Technology as an author, reviewer, editor and Editor in Chief until finally stepping down from all functions in 2021. In order to honour Prof. Olsson's devotion and contribution to the journals, IWA Publishing has compiled a Festschrift: that is, a book made up of contributions from Prof. Olsson's former students, his colleagues (past and present), and of course his friends. As the contributions testify, Gustaf's devotion and influence by far exceeds his work at Water Science and Technology. It has been a joy to read through the testimonies about Gustaf and how he has shaped and influenced lives and academic careers. They express an overwhelming gratitude for the way he has influenced and, in some cases, significantly formed both the professional and personal attitude of those he has touched. It also testifies to great scientific contributions, contributions that are strongly embedded in the water sector industry and with great impact at the time of publishing and clearly also well into the future. His leadership example is a source of inspiration to everybody in the water sector whether in academia or industry. We urge you to read this Festschrift to celebrate Gustaf and get inspired about how to work in service for the greater good of water. ISBN: 9781789063363 (print) ISBN: 9781789063370 (eBook) ISBN: 9781789063387 (ePUB)
... when the cooling water temperature tends to be higher than during the night [4] , they demand more water for cooling during the daytime. The global water consumption by the power generation sector is expected to double within the next four decades [5] . With CSP becoming an increasingly important renewable energy resource, it is expected to demand more cooling water in the future. ...
Article
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Concentrated solar power (CSP) plants are generally located in solar-abundant yet hot and water-stressed locations. In such circumstances, efficient but water-intensive once-through wet cooling and water-free but inefficient air cooling are both unfavorable. Considering both thermal efficiency and water availability/temperature, recirculating evaporative cooling is a better alternative. However, evaporative cooling still loses large amounts of water into the atmosphere and thus requires a nonstop water supply. Therefore, simultaneously reducing water loss and maintaining thermal efficiency requires efficient means of supplemental cooling for CSP plants. Here, following our previous work on scalable radiative cooling films and a kW-scale radiative cooling system (Zhai et al, Science 2017; Zhao et al, Joule 2019), we explore the potential of consumptive water use reduction in recirculating wet-cooled CSP plants by integrating supplemental radiative cooling and cold storage. Through modeling of a reference CSP plant with a supplemental radiative cooling system as large as the plant solar field, we show that 40 – 60 % of the annual consumptive water use can be potentially reduced in the hot southwestern US region with daytime-only radiative cooling, whereas the annual potential water saving can be as much as 65 – 85 % if the radiative cooling system works both day and night with cold storage.
... Bu yüzden son yıllarda evsel atıksu arıtımında yüksek enerji tüketimi olan konvansiyonel sistemler yerine enerji açısından verimli ve kaynak geri kazanımına elverişli teknolojiler tercih edilmeye başlanmıştır. AAT'lere gelen ham evsel atıksuyun, arıtma için gerekli olan enerjinin yaklaşık 10 katı fazla (13-15 kJ/g KOİ) enerji ihtiva ettiği bilinmektedir (Olsson, 2012). Atıksudan geri kazanılan enerji ile AAT'lerin enerji nötr ve hatta enerji pozitif işletilmesi mümkün hale gelmektedir. ...
... However, existing studies are mainly related to WDSs' (water distribution systems) energy efficiency improvements. Approximately 2-3% of the world's electrical energy is used for water supply and sanitation purposes, and 1-18% of the electrical energy in urban areas is used to treat and transport water and wastewater [56]. According to [57], the intensive cost of establishing a new pumping station and the everincreasing cost of energy has caused us to pay more attention to the optimal design and operation of drainage pumping stations. ...
Article
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In this paper, research on improving the economic efficiency of 38 drainage pumping stations was undertaken. Particular attention was paid to the effectiveness of activities without considering any expenditures. Energy costs for this type of machine are usually high, approximately 45% of the total maintenance cost. The main assumption of this work was the selection of appropriate energy tariffs to reduce operating costs. Liquid transport in any economy consumes significant amounts of electricity, estimated at 20–30% of the total electricity production. The optimization of the energy consumption of pumping processes is, therefore, very important. While analyzing the choice of energy tariffs, we designed profitability ratios (PR) specifically for different daily time zones. With the forecasted distribution of energy demands for different daily time zones (usually 2 or 3 zones), it was possible to compare multi-zone tariffs with 24 h tariffs. The profitability of the tariffs was decided by the value of the PR indicator. The lower, the better. In practice, this meant that the analyzed multi-zone tariffs, in most cases, are more profitable compared to single-zone tariffs. In the Polish energy system, each entrepreneur, depending on the connection power, has a right to choose a particular energy tariff from three tariff groups, i.e., high (A), medium (B), and low (C) voltage. In the case of land reclamation pumping stations, energy tariffs are usually from groups B and C. The choice of tariffs largely depends on the contracted capacity and is determined by tariff regulation. Nowadays, the current energy system forces entrepreneurs to declare a connected power load at the level corresponding to the maximum use of the production potential. Lack of knowledge of the hydrological regime, quite common for land reclamation pumping stations, usually results in overestimating the contracted capacity. When comparing the effect of changing tariffs, it was found that the profitability of this method is significant. The four-year study period (2010–2013) showed that active energy in the multi-part tariffs of groups B and C is on average 10.2% cheaper than in the single-part tariffs and varies in a wide range from 2% to 20.4%. The analysis carried out on 38 drainage pumping stations shows that for only five pumping stations could changing the current tariff be unjustified. In the other cases, the four years of analysis demonstrates that changing the current energy tariff could reduce electricity costs by approximately 5%., i.e., approximately PLN 124,000 per year (approximately EUR 27,000).
... A staggering 90% of the total energy used for urban water services (drinking water treatment, water supply, wastewater transport through sewer system and treatment) is spent on heating tap water for domestic needs (Olsson 2012). A large percentage of this heat energy is discharged into the sewer system and lost to the environment (soil, sewer pipes, in-sewer air, etc.) before reaching the wastewater treatment plant (WWTP) (Somogyi et al. 2018). ...
Article
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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. HIGHLIGHTS Modelling tools to study energy recovery possibilities from wastewater are needed.; Mechanistic and conceptual models for temperature dynamics in sewer system are developed.; The models are applied for sewer pipes in two Swedish cities – Linköping and Malmö.; Both models offer similar prediction capabilities.; Further studies should include case studies outside Sweden and longer time periods.;
... Aeration is a key component to design wastewater treatment plants (WWTPs), particularly activated sludge processes because the aeration energy is supposed to be more than half of the total energy consumption in the WWTPs [1,2]. In this regard three affairs are considered in the aeration design: air supply system, oxygen transfer and oxygen demand. ...
Article
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Ascertaining peak oxygen demand is crucial for plant designers to determine blower capacities of wastewater treatment plants in planning phase. To obtain this technical information without cumbersome influent sampling and analysis, a set of field-test activated sludge reactors equipped with DO and nitrate-N sensors was installed at 3 sites and continuously operated for a couple of months in each field. Under the controlled aeration and hydraulics of the reactors, the hourly influent oxygen demands were back-calculated as biodegradable constituents using the IWA-Activated Sludge Model #1. The daily maximum concentrations (rounded to last for 1-hour) of biodegradable organics and nitrogen were ranged between 45~258 mg-COD/L and 10.4~32.3 mg-N/L in Site #1; 119~244 mg-COD/L and 28.3~38.7 mg-N/L in Site #2; 194~552 mg-COD/L and 30.2~51.7 mg-N/L in Site #3 respectively. The marginal blower capacities to maintain at least 1.0 mg-O2/L of DO in the daily maximum oxygen demand were estimated based on the datasets using the statistical method, Extreme Value Distribution analysis. To maintain the DO concentration for 99 days out of 100 days of the plant operations, the blower capacity was supposed to be designed as high as 1.4~2.2 times than those of the blower calculated from the daily average concentration.
... In China, 67% of energy production occurs in water-shortage areas (Cai et al., 2014). Energy production and consumption require large amounts of water resources, intensifying the conflict of water supply and demand (Olsson, 2015;Mekonnen and Hoekstra, 2016;Liang et al., 2020). The constraints of water resources on energy have become an essential aspect of energy security (Jacobson and Delucchi, 2011). ...
Article
S As the basis of urban social-economic development, water and energy resources are indivisible and interrelated in the production and consumption activities of cities. The frequent intercity trade of energy-related goods aggravates water withdrawal in neighboring cities and causes the spatial transfer of resources. The spatial correlation of water withdrawal and energy consumption is rarely considered in the city-level water-energy nexus. As one of China’s most serious water shortage regions, Hebei Province is the third-largest energy consumer in China and is a major supplier of mineral resources, industrial raw materials, water resources, electricity, and agricultural products to Beijing and Tianjin. The spatial Durbin model with the two-way fixed effects is applied to explore spatial effects of water-energy nexus in cities of Heibei province. Seven influencing factors, including energy consumption, energy structure, population, GDP, water withdrawal intensity, urbanization, and agriculture structure were considered. Results showed that all factors had positive impacts on water withdrawal except energy structure. Water withdrawal intensity made the most considerable contribution to water withdrawal, followed by urbanization, energy consumption, GDP, industrial structure, and population. The urbanization level of neighboring cities exerted the most significant positive spatial spillover impact on local water withdrawal, whereas the energy consumption showed a negative impact. The exploration of city-level spatial correlation regarding water withdrawal and energy consumption provides a reference for regional cooperation to improve resource utilization efficiency, establishing sustainable energy and water systems, and promoting sustainable development.
... As a consequence of sub-optimal operations, both pumping power and water leakages in the network can be increased. It leads to wastage of energy used for pumping waters, resulting in a water shortage in most water sources and distributions [9]. ...
Conference Paper
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Sustainable development for affordable and clean power supply can be achieved through the maximization of energy conservation and energy generation by renewable sources. In recent decades, the need for water has risen enormously, and due to this, the water supply sector is one of the high energy users. Any energy savings in the water distribution network will reduce the economic and environmental problems. Pressure reducing valves (PRVs) are widely used for regulating excessive pressure in water distribution networks (WDNs). However, in recent years many efforts have been carried out for the implementation of pump-as-turbine (PAT) instead of PRVs for pressure regulation by energy generation as an added advantage. In the present study, the state of the art review on implementation of pump-as-turbine in the water distribution network for power generation has been presented. Investigations of site selection for the pump as a turbine, selection of suitable pump running as a turbine for WDN, various methods of performance enhancement carried out by different researchers have been critically reviewed. Further, directions for future research are suggested.
... It has also been shown that energy consumption worldwide is increasing rapidly [14]. Energy consumptions related to water processes account for 2-3% of the world's electricity thus the energy management of wastewater treatment plants (WWTPs) is considered a current topic [15]. There are numerous methods to determine the energy efficiency but few researchers have taken into account the energy cost. ...
Article
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The aim of this paper is to predict the energy consumption of a wastewater treatment plant from Romania, taking into account the flowrate, concentration of BOD, TSS, COD and the energy consumption. For the mathematical model the logistic regression was applied. The input data used were from a waste treatment plant in Romania, for a period of 2 years 2015 and 2017, a total of random 403 dataset. The treatment technologies of WWTP consist of advanced biological treatment SBR (nitrification, denitrification, and phosphorus removal), aerobic sludge stabilization, dewatering, storage and chemical disinfection. Octave software was used to build the model. The answer of the model refers to the fact that for a given situation there will be high energy consumption or low energy consumption in the wastewater treatment plant (WWTP). Performance of the model was compared with real value.
... In addition, the recent work of Matu sinec et al. [24] has established that waste animal fats have a promising potential in the upcoming years to allow for not only the production of biodiesel but also biodegradable polymers, thermal and electric energy. Currently, more than 80% of the world's primary energy comes from fossil fuels, with crude oil up to 32.8%, coal, 27.2%, and natural gas, 20.9% [25][26][27]. The production of biodiesel is one of the most attractive and fast-expanding applications of clean, renewable, and sustainable energy sources in recent times [28,29]. ...
Article
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This study investigates the effect of zeolite nano-catalyst on the yield of biodiesel and biochar formed from the pyrolysis of tallow (cow fat). Residual waste cow fat was pyrolyzed in a fixed-bed reactor of laboratory-scale volume 2200 cm3 , at operating temperatures of 450, 500, 530, and 580 �C and heating rates of 4, 5, and 6 �C/min. The molecular composition of cow fat was analyzed using a gas chromatography molecular spectrograph (GC-MS). It was observed that the biodiesel produced without a catalyst was mainly composed of aromatic carboxylic acids, esters, alkanes, alkenes, and alkanes, while the biodiesel produced with zeolite nano-catalyst consisted mainly of methyl esters, pentanoic acid, heptanoic acid, cyclo-olefins, 4,4-dimethylcyclohexene, butyl-cyclo�hexane, butyl-cyclopentane, and 1-pentylcyclopentene. A biodiesel yield of 58% was achieved when a 1% zeolite nano-catalyst was used to pyrolyze the tallow at an operating temperature of 530 �C and heating rate of 6 �C/min. When the tallow was pyrolyzed without a zeolitic catalyst, decarboxylation was promoted, and a higher biodiesel yield of 82.78 wt% was achieved. Results from this study revealed that although zeolite nano-catalyst did not show an incremental effect on the yield of biodiesel, it favors biogas production and biochar formation.
... The methods applied in the estimation of water required for energy generation include life cycle analysis (LCA), material flow analysis (MFA), input-output (I-O), process-based analysis, and a combination of various methods (such as, I-O-LCA) [9][10][11][12]. The LCA method shows the amount of water used in entire energy generation processes e.g., raw material extraction, transportation, and material processing. ...
Article
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The relationship between water and energy is a strong one characterized as having integration and coupling as two important features. While energy is responsible for delivering water to the end-users, it needs energy in order to be generated, and water. In this paper, a thorough review is presented regarding the different relationships between water and energy in terms of (i) the significance of the close relationship between water and energy by means of water/energy generation and consumption. Water consumption, water cooling and heating must be taken into account in order to avoid the obstacles related to future use of water for energy generation; (ii) the measuring and monitoring technologies for the energy-water nexus, focusing attention on the variables that are interrelated in the water and energy sectors. In addition, the consequences of finding several parameters, unknown variables and unclear dependencies in measuring of energy usage in the applications of water usage should also be taken into account. Innovative developments including nanotechnology, biotechnology, and wireless networks, as sensor technologies, may resolve the challenges of sensing; (iii) the different key performance indication tools for assessing and quantifying this nexus by analyzing and categorizing recent case studies of the water energy nexus and applicable evaluation methods; and (iv) the different research dimensions conducted on this nexus. Hopefully, this review will contribute to the development of this nexus adding value to the field while reducing duplication efforts.
... Traditionally, agriculture, and, later, energy production have represented the most water-intensive activities worldwide. Extensive research has taken place into water for irrigation and food production [4][5][6], and studies on water for energy have abounded in recent years [7][8][9]. Population growth and economic development have created increasing pressures on freshwater resources, which, coupled with the particular circumstances of the resource (i.e., limited and uneven availability) have, over time, led to tensions among freshwater competitors. The competition between communities for the control of, and access to, water has even on occasions resulted in violent conflicts [10][11][12]. ...
Article
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Water resources are limited and uneven in space and time. Competition for the use of the resource can lead to conflicts between water users. Besides its use for irrigation and agriculture, water is an essential input in the thermoelectric power generation process. Massive Spanish nuclear program projects have conditioned water management in the country, as significant freshwater volumes need to be constantly available for the proper operation of these facilities. Water for cooling has conflicted with other water-using activities, resulting in regional imbalances. The present study shows that cooling water represented a source of conflict between irrigators and electricity companies in Spain in the 1970s and 1980s. A historical analysis of documentary sources reveals that the drawing off of fresh water for cooling by the nuclear industry was one of the many causes of frequent disputes and the rise of social movements against the installation of nuclear power plants in Spain during that period.
... Biogas is mainly composed of 40%-75% CH 4 and 15%-60% CO 2 by volume with small amounts of hydrogen (H 2 ), nitrogen, hydrogen sulfide, oxygen, and water (Ryckebosch et al., 2011). It is a decomposition process that naturally occurs in swamps, water-logged soils, rice fields, and digestive systems of termites and large animals (Olsson, 2012). It is an established technology that has been commercialized in municipal WWT plants since the early 1900s. ...
Article
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While traditional anaerobic digestion (AD) process to produce methane-rich biogas from wet waste is deep-rooted, high carbon footprint and its low value as compared to other renewable sources demand advanced strategies to avoid its production. An emerging conversion pathway to arrest methanogenesis for producing value-added fuels and chemicals instead of biogas, is sought as a sustainable alternative. This research provides a comprehensive analysis on current technology development, process challenges, applications, and economics for producing high-value short-chain carboxylic acids from AD of wet wastes. We show that (1) the theoretical energy yields of acids equal or exceed biogas, and (2) the cost of these acids is competitive with those produced from chemical markets, making this economically viable for mass production. With global abundance of wet waste feedstocks, this process of short-chain acid production provides a promising alternative to conventional biogas production technology, while achieving waste management and carbon mitigation goals.
... The US is not a particular area of high consumption either; 3% of all UK energy use is expended on drinking and wastewater systems (Fletcher, 2018). In fact, it is likely that these countries have low energy consumption from their water utilities relative to the rest of the world (Olsson, 2015). The United Nations stated that approximately 8% of global primary energy supply is used to deliver and treat water ( UN Water, 2014;UNESCO, 2014). ...
Article
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Water companies consume up to 8% of global energy demand, at billions of dollars’ cost. Benchmarking of performance between utilities can facilitate improvements in efficiency; however, inconsistencies in benchmarking practices may obscure pathways to improvement. The aspiration was to conduct an unbiased efficiency comparison within a sample of 17 water only companies and water and sewerage companies in England and Wales, accounting for exogenous factors, whilst evaluating the accuracy of common proxies. Proxies were tested, and bias-corrected energy and economic efficiency scores with explanatory factors were analysed using a double-bootstrap data envelopment method. Bias correction altered the rankings of two companies for energy efficiency only. Results imply that on average, companies could reduce energy inputs by 91.7%, and economic inputs by 92.3%, which was symptomatic of the companies specialising in drinking water supply considerably out-performing combined water and sewerage companies. As exogenous influences were likely to be a factor in the disparity between the companies, five indicators were evaluated. The results varied but of note were average pumping head height, which displayed a significant negative effect for energy efficiency, and proportion of water passing through the largest four treatment works, that exhibited a significant negative effect on economic efficiency. Within proxy performance, population served for drinking water was an adequate replacement for volume of water produced, with results matching the core variable apart from two companies changing rank in the economic analysis. Conversely, length of water mains performed poorly when replacing capital expenditure, implying companies were on average 12.6% more efficient, resulting in ten companies changing their rank and causing explanatory variables to contradict direction of influence and significance. The findings contribute new insights for benchmarking, including how different types of water companies perform under bias-correcting methods, the degree to which factors affect efficiency and how appropriate some proxies are.
... Clean and sustainable water supplies and low carbon energy access are the essential building blocks for economies, health and quality of life. Present day energy and water systems are interdependent and have to be addressed together (Olsson, 2012). Extraction, treatment, carriage and management of drinking water and treatment of wastewater are both dependent on a substantial amount of electrical energy. ...
Conference Paper
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Cross-sectoral coupling is one of the newly emerging research topics that refers to the idea of interconnecting and integrating the energy consuming sectors like buildings (heating and cooling), transport, water supply systems and other energy intensive process with the power-producing sector. The cross-sectoral integration of the water-energy nexus and the sustainability issues surrounding the availability of clean water and energy has drawn the attention to the problem from all around the globe. Smart decision-making and control systems can improve the efficiency of the overall operation of both water and energy systems. At a technological level, there have been attempts to optimize coupling points between the electricity and water systems to increase efficiency of both. Most of the optimization and smart decision-making systems focus on energy system and consider heterogeneous infrastructure in the form of energy consumption devices. In the scope of water-energy nexus, energy effic ient decisions would have implications on water infrastructure. Tools and platforms for water-energy nexus are required, such that planning and executing the decisions and their implications on both energy and water infrastructure can be seen. Most of the existing controllers are specifically designed to efficiently serve either energy or water systems. In this paper, we propose a software architecture for the platform that is capable of monitoring, controlling, decision making and analysing the effect of decisions for water and energy nexus.
Preprint
This paper presents a comprehensive analysis of spiral water flow dynamics and its implications for energy efficiency in hydropower dam designs. Applying principles of fluid mechanics, conservation of energy, and rotational dynamics, Mathematical models are derived that characterize the energy transformations within the system.The paper presents theoretical derivations and simulations that characterize the energy changes within the system and compare the spiral flow dam's performance with traditional designs. The results show that the novel strategy can greatly increase hydrodynamic efficiency, providing a workable way to raise the output of renewable energy. A similar spiral flow mechanism is used in spiral pumps and spiral turbines for minimumenergy loss and maximum efficiency
Book
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This text is designed to teach how to account for the flow of energy in pollution prevention and control processes. Conservation of Energy is a fundamental principle. Topics include energy conversion, making the energy balance for combustion and incineration, biogas management, heat exchange, and energy use for pumping.
Article
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This review article positions water front-and-center as a key enabler of water–energy–food (WEF) nexus systems. It demonstrates the critical role of water in human civilization, progress, and development, including how water is central to the achievement of many of the United Nations’ sustainable development goals. It is suggested that water may in fact be the most important resource needed in a broader WEF nexus context, as well as in the broader scope of human development. The review shows the consequences of ‘water going wrong’ – when there is too much or too little, and the global impacts of increasing frequency of such events, largely due to an ever more ‘hyperconnected’ world. The review concludes by urging greater ‘nexus awareness’ and systems thinking, especially in policy and decision-making, while cautioning against the potentially ironic situation of returning to a sectoral, water-centric view of resources management.
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Today, most irrigation systems consume energy and a large part use groundwater at rates higher than the aquifer recharge, thus forcing farmers to pump at ever lower levels (more energy consumption, and thus higher cost). The energy consumption of irrigation systems is mainly considered as a technical challenge with the objective to improve its performance. In this work we propose to evaluate the energy requirement of irrigation systems and analyze the results through a functional perspective. A bibliographic review is sorted based on the successive evaluation of environmental impacts of irrigation infrastructures and the direct energy demand in relation to water path. As food, water and energy issues are interdependent, a new conceptual framework is proposed to discuss the results and support the decision-making process. Adding a social-ecological dimension to the engineering issue of maximizing water productivity balanced with energy efficiency offers many perspectives towards the consideration of agriculture as provider of public goods.
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Unit energy consumption per kg pollutant removed (kWh/kgCODremoved) is used for the first time in assessing and ranking the sustainability of main treatment technologies of 1,215 wastewater treatment plants (WWTPs) in China. The metric reflects more accurately the sustainability of main treatment technologies in WWTPs than unit energy consumption (kWh/m³). The energy consumption data of these WWTPs were selected from the database of 1,399 WWTPs to evaluate the energy efficiency of the treatment technologies. 80.3% of the WWTPs in China used anaerobic-oxic plus anaerobic-anoxic-oxic, oxidation ditch, and sequencing batch reactor as main technologies. Statistical analysis showed that the unit energy consumption of WWTPs decreases with increasing design flow rate, operation loading rate, and influent COD concentration. For example, the average unit energy consumption of SBR decreased from 2.76 kWh/kgCODremoved to 0.83 kWh/kgCODremoved when the design flow rate increased from less than 10,000 m³/d to 100,000-200,000 m³/d. The mean unit energy consumption of SBR decreases from 1.71 kWh/kgCODremoved to 1.32 kWh/ kgCODremoved and 2.85 kWh/ kgCODremoved to 0.63 kWh/kgCODremoved as the operation loading rate and COD removal increase from 40% to 100% and from less than 150 mg/L to over 450 mg/L, respectively. SBR has the lowest unit energy consumption among all the treatment technologies. Therefore, SBR might be the most appropriate technology in small and medium-scale WWTPs in China. Regression equations were developed to predict the unit energy consumption for future sustainable treatment design by input variables such as design flow rate, operation loading rate, and influent COD concentration.
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Automation is a collection of a whole set of theories and methods to make a system work automatically as intended, in our case the urban water supply system. A critical feature of automation is the feedback principle: a sensor is measuring a certain variable, e.g. a concentration; a computer tests that the measurement is valid; a computer algorithm calculates and decides what should be corrected; a pump or valve or some other device transforms the decision to action. All of this is untouched by human hand. The ‘intention’, or the goal, must be provided to the controller. The key component of automation is the system that can represent any component or process in the water supply system and even the complete system. Automation technology always must be combined with a true understanding of people at all levels. Otherwise, there is a high risk for misunderstandings and failures. Three categories of problems are highlighted, where automation can contribute: uncertainty, feedback, and complexity. A key challenge is the handling of disturbances. Integrated management of the whole urban water cycle will be required in future urban areas to acquire sustainable operations. Automation is a crucial condition to make integration possible in complex systems. HIGHLIGHTS Dealing with uncertainties by online monitoring.; Using feedback at all levels to correct deviations from ‘normal’ operation.; Handling disturbances, particularly in time scales too fast or too slow for human interaction.; Operating complex highly interactive systems as well as small-scale decentralized systems.; Operation of the integrated urban water supply system.;
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The current organization of water supply systems demands drinking standards for all the households' usage of water. Few dual water systems, i.e., systems in which the quality of the water supplied is differentiated by types of use, exist but are mainly circumscribed to developing countries. Besides, bath and showers are so far considered as a potable use of water despite only drinking and cooking activities requiring the high-quality standards of potable water. The present work demonstrates how the principles of dual water systems can be incorporated into the sustainable concept of product-service system (PSS) using a dual water system of a municipal water supply treatment plant in France as a case study. The PSS is based on the water quality, and the bathing activity of households is considered with a dedicated standard for the first time. Two systems are considered, S1 and S2, supplied with the same raw water quality and treated with drinking (S1) bathing standards (S2). The quality parameters considered are total organic carbon (TOC) and turbidity (T) and the potential savings related to costs, material, and energy consumptions are assessed using EVALEAU as a process modeling tool. The treatment lines consisted of powdered activated carbon (PAC) addition, coagulation, flocculation, settling, and rapid sand filtration. Results show that material consumption can be reduced by 41% mainly through the decrease in chemical consumption associated with the change of requirement for the TOC parameter. On the opposite, energy consumption was found dependent on the water of volume treated rather than its quality leading to only marginal savings. The cost was decreased by 37% as a result of the reduction of the chemicals consumed.
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We assess the sustainability of rural electrification in Manica Province, Mozambique, focusing on different alternatives for mini-grid and off-grid power supply. The qualitative assessment considers four dimensions of sustainability, namely environmental, socio-cultural, economic, and institutional. We argue that small-scale hydropower is the most sustainable alternative for off-grid or mini-grid solutions in rural Manica Province with good possibilities to scale up this to the major parts of rural Mozambique. The investigation shows that social acceptance for small-scale hydropower is high. Environmental sustainability of small-scale hydropower is higher than for PV systems. To speed up the electrification process, efficient rural electrification has to connect policy to local scale and institutional strengthening. The legislation needs to be improved, and there is a need for better institutional coordination for hydropower mini-grids’ regulation. Along this line, a national framework to support small and independent power producers is necessary.
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