Throughout the world, much food produced is wasted. The resource impact of producing wasted food is substantial; however, little is known about the energy and water consumed in managing food waste after it has been disposed. Herein, we characterize food waste within the Food-Energy-Water (FEW) nexus and parse the differential FEW effects of producing uneaten food and managing food loss and waste. We find that various food waste management options, such as waste prevention, landfilling, composting, anaerobic digestion, and incineration, present variable pathways for FEW impacts and opportunities. Furthermore, comprehensive sustainable management of food waste will involve varied mechanisms and actors at multiple levels of governance and at the level of individual consumers. To address the complex food waste problem, we therefore propose a “food-waste-systems” approach to optimize resources within the FEW nexus. Such a framework may be applied to devise strategies that, for instance, minimize the amount of edible food that is wasted, foster efficient use of energy and water in the food production process, and simultaneously reduce pollution externalities and create opportunities from recycled energy and nutrients. Characterization of FEW nexus impacts of wasted food, including descriptions of dynamic feedback behaviors, presents a significant research gap and a priority for future work. Large-scale decision making requires more complete understanding of food waste and its management within the FEW nexus, particularly regarding post-disposal impacts related to water.

Urban agriculture is booming. During case study Water-Energy-Food nexus research at urban farms, investigation indicated two types of ‘food’ to be relevant for urban agriculture. Consequently, the ‘food’-component in the WEF nexus is split, which leads to a Water-Energy-Nutrients-Food (WENF) nexus framework for urban farming. This systematic WENF nexus monitoring, analysis and evaluation framework aims to facilitate acquisition of quality data during case study research at farming sites, in order to fill the quantitative data gap regarding urban agriculture and closed circularity loops. Stocks of various types of water, energy, nutrients and food are differentiated and flows within each described. Subsequently, multi-sectoral flows between the four main resource stocks and their interactions and interdependencies are identified with the aim of formulating options for circularity in urban farming. The analysis shows that urban systems offer many opportunities for the realisation of sustainable agriculture in cities because waste management and farming could mutually reinforce each other. Local reuse of resources found in urban “waste” has the potential to reduce stormwater nuisances, energy needs for water, nutrient and food transport, irrigation, and wastewater pumping while eliminating the need for synthetic soil improvement and unsustainable mineral mining. All in all, reusing resources from urban (waste)waters in urban farming initiatives can reduce the negative impact of food production on the environment.

The increase in world population and the resulting demand for food, water, and energy are exerting increasing pressure on soil, water resources, and ecosystems. Identification of approaches to reduce the related cross-sectoral environmental impacts for the water–energy–food nexus is, therefore, crucial. The purpose of the review was to discuss the circular economy approaches devoted to understand the interdependencies among these three sectors. In particular, the review focuses on the importance of the application of life cycle thinking and life cycle assessment for understanding the interconnections in the nexus along the whole supply chains. Moreover, researches related to water and energy use in the agrifood sector are presented, addressing food waste management alternatives in a circular economy perspective.

With rise in population growth and increasing trend towards urbanization, urban spaces have become ‘hot spots’ for intensive resource use including water, energy and food (WEF). Thus, along with food production, food management from consumption side is equally important to address the issue of WEF resource scarcity. An analysis of urban food management in India was carried out through systematic study of different government documents. In-depth content analysis across five sectors, namely water, energy, food, urban and environment, was carried out to find parameters for urban food management strategies having linkage with WEF resources. The study identified six parameters under two categories, namely city region food systems (urban/peri-urban agriculture, green roof technology, urban farmers market) and managing food wastes (reducing food wastes, compost from waste, energy from wastes). The analysis revealed that urban food management in India is focused on managing food wastes through solid waste management strategies (compost and energy production). City region food system and role it plays in optimizing WEF nexus need the attention of policy makers. The study concludes that a paradigm shift is required towards integrated urban WEF policy to attain the goals of sustainable urban development in the developing nations of Global South.

Urbanisation will be one of the 21st century's most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. N50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

EWRI International Conference Jan 5-7, 2010 - Chennai, India. Presented, 7th Jan, 2010 in Poster Session #5. Conference title: '3rd international perspective on current & future state of water resources & the environment'

A ‘nexus’ approach, comprising interrelated systems components of energy, water, and food, has been suggested to accelerate progress towards achieving sustainable development goals on food waste and related issues, like climate change. The current body of literature usually focuses on food security, especially in relation to production and waste management in the supply chain. The food service sector (FSS), a major consumer-facing component of the food system, has often been overlooked or neglected. There exists, then, an opportunity to better understand the interlinkages between food waste, energy, water, and emissions – the FEWE Nexus – to assist this sector in developing more sustainable operations, such as kitchen equipment management and menu development. To fill this gap, we introduce a novel FEWE Nexus Framework, to understand the flow of nexus components associated with receiving, storing, preparing, cooking, cleaning, and serving menu items. A key aspect of the methodological approach for FEWE evaluation is life cycle assessment (LCA). This is embodied in a comprehensive nexus audit tool comprising several indicators to monitor and quantify energy and water consumption, emissions from cooking, food waste generated, and type and efficiency of equipment used. Further, a stakeholder engagement survey is integrated, allowing for stakeholder feedback on applications of the audit tool, and to assess the impacts and acceptance of potential interventions. Finally, we describe how an iterative nexus approach can enable decision makers in the FSS to robustly estimate nexus components and establish a baseline to track their progress towards minimizing wastages and maximize efficiency.

Current studies on the food-energy-water nexus do not capture effects on human health. This study presents a new methodology for assessing the environmental sustainability in the food-energy-water-health nexus on a life cycle basis. The environmental impacts, estimated through life cycle assessment, are used to determine a total impact on the nexus by assigning each life cycle impact to one of the four nexus aspects. These are then normalised, weighted and aggregated to rank the options for each aspect and determine an overall nexus impact. The outputs of the assessment are visualised in a “nexus quadrilateral” to enable structured and transparent interpretation of results. The methodology is illustrated by considering resource recovery from household food waste within the context of a circular economy. The impact on the nexus of four treatment options is quantified: anaerobic digestion, in-vessel composting, incineration and landfilling. Anaerobic digestion is environmentally the most sustainable option with the lowest overall impact on the nexus. Incineration is the second best option but has a greater impact on the health aspect than landfilling. Landfilling has the greatest influence on the water aspect and the second highest overall impact on the nexus. In-vessel composting is the worst option overall, despite being favoured over incineration and landfilling in circular-economy waste hierarchies. This demonstrates that “circular” does not necessarily mean “environmentally sustainable.” The proposed methodology can be used to guide businesses and policy makers in interpreting a wide range of environmental impacts of products, technologies and human activities within the food-energy-water-health nexus.