Waste water as a source for secondary resources and linkage to other urban systems

Urban metabolism studies have shown that, in terms of sheer mass, water is the largest and the most vital component. Population growth and higher living standards will cause ever increasing demands for good quality municipal and industrial water, and ever increasing sewage flows within a limited area. Within this paper we will address the question whether there are better ways of meeting the various qualities and consequently reduce our water needs. The quantitative assessment of water quality and its relationships with management activities is a necessary step in efficient water resources managemen

Expanding the exergy concept to the urban water cycle

The world is urbanizing fast and this increases the pressure on available resources. In a world of cities, it is therefore crucial to take a new look at the way urban systems function: where do the resources come from and where do the wastes end up? It is essential to find ways to minimize urban impacts on resource depletion and environmental impacts and also to improve cycles within the systems. Energy and water cycles are vital to support urban life. Over the last decades, important advances have been made separately in the field of integrated water management and energy efficiency in urban areas. However, for urban planning purposes a shared framework is required that allows planners to model and understand the dynamics of the broader system to achieve an integrated management of the resources. Natural energy and water cycles are modified by metabolic profiles of the cities. The metabolic profile varies with the local resource availability and the level of technological development. To cope with this complexity, the concept of Exergy, based on Thermodynamic laws, and defined as the non-used fraction of energy, has been used to understand the energy cycle in the built environment. This will lead to new approaches towards urban planning and better resources use. This paper aims to find out if the exergy concept can be expanded to the water cycle defined as the use of the non-used water(-fraction). This way the cycle can be optimized and closed at a high efficiency level. In order to achieve this, we want to study to what extend the energy and water cycles are comparable, and how they can learn from each other in order to optimize their management

Low impact urban design by closing the urban water cycle

Abstract Current fast urbanization and increasing quality of life result in increments on resources’ demand. Increasing resources demand implies as well increments on waste production. However, limited availability of resources such us: oil, fresh water, phosphorus, metals (Boyle et al., 2010, Gordon et al., 2006; Rockström et al., 2009) and limited earth’s productive and carrying capacity (Rees, 1999) are potential restrictions to urban growth and urban sustainability. These pressures, however, are drivers towards more efficient resource use. In a world of cities, urban systems play a key role to find solutions for these global pollution and depletion problems (Xu et al., 2010). To alleviate these pressures, it is needed to minimize demand and to shift from linear to circular metabolism, in which recycling and reusing are key activities (Girardet, 2003)

Dynamic water resource management for achieving self-sufficiency of cities of tomorrow

Steden kunnen beschouwd worden als producenten van primaire en secundaire grondstoffen. Volgens onze hypothese, moet deze zelfvoorziening uitgaan van de kleinst mogelijke ruimtelijke schaal. De mogelijkheden om energie en water in Nederland te ‘oogsten’ zijn geëvalueerd, uitgaande van gemiddelde jaarcijfers. De resultaten op nationale schaal laten zien dat het mogelijk is om aan 100% van de elektriciteitsvraag, 55% van de warmtevraag en 52% van de watervraag te voldoen. In werkelijkheid zijn er echter beperkingen aan deze mogelijkheden tot oogsten als gevolg van de dynamiek in grondstof- en energiestromen, stedelijke typologie en technologische (in)efficiëntie. Om de werkelijke oogstpotenties te kunnen bepalen is daarom dynamische modellering nodig op relatief fijne tijd- en ruimteschalen. Op gebouwniveau zijn scenario's onderzocht met verschillende strategieën zoals het minimaliseren van de vraag, en het verkrijgen van secundaire kwaliteit water voor toiletspoeling en wasmachinegebruik door recyclen van licht grijs water (LGW) en het opvangen van regenwater (multi-sourcing)

Duurzaam ontwerp van de aan- en afvoer van drinkwater

Het simulatiemodel SIMDEUM geeft een betrouwbare voorspelling van koud- en warmwaterverbruik in woningen, gebouwen en utiliteitsbouw en kan daardoor een cruciale rol spelen bij het bevorderen van duurzaamheid in de waterketen. Zo leiden op het model gebaseerde rekenregels tot energie-efficiënte ontwerpen van leidingwaterinstallaties. Ook maakt het model het mogelijk grijs- en hemelwatersystemen goed te dimensioneren en geeft het inzicht in de kwantiteit en kwaliteit van het afvalwater, zoals temperatuur en concentratie aan nutriënten. Deze informatie is nodig in processen waarin energie of nutriënten uit afvalwater teruggewonnen worden

Drinking water temperature around the globe : understanding, policies, challenges and opportunities

Water temperature is often monitored at water sources and treatment works; however, there is limited monitoring of the water temperature in the drinking water distribution system (DWDS), despite a known impact on physical, chemical and microbial reactions which impact water quality. A key parameter influencing drinking water temperature is soil temperature, which is influenced by the urban heat island effects. This paper provides critique and comprehensive summary of the current knowledge, policies and challenges regarding drinking water temperature research and presents the findings from a survey of international stakeholders. Knowledge gaps as well as challenges and opportunities for monitoring and research are identified. The conclusion of the study is that temperature in the DWDS is an emerging concern in various countries regardless of the water source and treatment, climate conditions, or network characteristics such as topology, pipe material or diameter. More research is needed, especially to determine (i) the effect of higher temperatures, (ii) a legislative limit on temperature and (iii) measures to comply with this limit

Resource management as a key factor for sustainable urban planning

Due to fast urbanization and increasing living standards, the environmental sustainability of our global society becomes more and more questionable. In this historical review we investigate the role of resources management (RM) and urban planning (UP) and propose ways for integration in sustainable development (SD). RM follows the principle of circular causation, and we reflect on to what extent RM has been an element for urban planning. Since the existence of the first settlements, a close relationship between RM, urbanization and technological development has been present. RM followed the demand for urban resources like water, energy, and food. In history, RM has been fostered by innovation and technology developments and has driven population growth and urbanization. Recent massive resource demand, especially in relation to energy and material flows, has altered natural ecosystems and has resulted in environmental degradation. UP has developed separately in response to different questions. UP followed the demand for improved living conditions, often associated to safety, good manufacturing and trading conditions and appropriate sanitation and waste management. In history UP has been a developing research area, especially since the industrial era and the related strong urbanization at the end of the 18th century. UP responded to new emerging problems in urban areas and became increasingly complex. Nowadays, UP has to address many objectives that are often conflicting, including, the urban sustainability. Our current urban un-sustainability is rooted in massive resource consumption and waste production beyond natural limits, and the absence of flows from waste to resources. Therefore, sustainable urban development requires integration of RM into UP. We propose new ways to this integratio

Harvesting urban resources towards more resilient cities

With accelerating global changes, cities have to cope with growing pressures, especially for resource supply. Cities may be considered as resources reservoirs and producers of secondary resources. This paper introduces the concept of urban harvesting as a management tool to change inefficient linear urban resource usage and waste production into sustainable urban metabolism. The Urban Harvest concept includes urban metabolism and closing urban cycles by harvesting urban resources. The purpose of this study was to quantify the potentials to harvest water and energy at different scales. We investigated potentials for the Netherlands. Results show that at national scale, potentials can cover up to 100% of electricity demand, 55% of heat demand and 52% of tap water demand. At neighborhood level, similar percentages were found for energy. Only 43% of water demand was achieved, due to fact that treatment measures were not considered. These results indicate the large potential of cities as providers of their own resources. Therefore urban resources management is a key element of future city design towards more resilient cities