Water, energy, and food are essential for human well-being and for sustainable development. Water is required in almost all types of electricity generation and it is highly consumed in food production. Cities, industry, and crop production have increased their needs for water, energy and land resources, and at the same time, they are facing problems associated with the environmental degradation and, in some regions, resource scarcity. This paper proposes a multiobjective optimization model for the design of a water distribution network from a water–energy–food nexus point of view. Additionally, crop production and cost relationships are integrated to account for the water and energy requirements in the agricultural sector. The economic objective is the maximization of annual gross profit, which accounts for the water, energy and food production; the environmental objective establishes the minimization of overall greenhouse gas emissions, and the social objective is the maximization of the number of jobs. In this paper, because the objectives are opposites, a multistakeholder assessment is proposed in order to analyze and quantify the relationship of the water–energy–food nexus to assess synergies that improve the decision-making process. The mathematical model was applied to a case study located in the Sonoran Desert in Mexico, in which, a series of scenarios were solved to illustrate the capabilities of the proposed optimization approach. The results show strong trade-offs between the considered objectives as well as the quantification of the water–energy–food nexus.

Juveniles (3.5 ± 0.3 g) of the white shrimp Litopenaeus vannamei were grown during 40 days with no water exchanges, no food addition and four initial densities (25, 50, 75 and 100 g m-3, corresponding to between 8 and 32 shrimp m-2), to determine growth rates, which could be achieved using the periphyton growing on artificial substrates as the only food source. The experimental culture units were 12 polyethylene 1 m³ cylindrical tanks with 4.8 m² of total submerged surface (bottom and walls), provided with 7.2 m² of artificial substrate (Aquamats&#8482;). There were no significant differences in the ammonia and nitrite concentrations determined in the four treatments (0.17-0.19 and 0.10-0.11 mg L-1, respectively), which remained below the respective levels of concern for shrimp cultures. Mean survival was similar, and ranged from close to 91 to 97%, whereas there were significant differences in mean individual weight, which ranged from 11.9-10.6 g shrimp-1 for the two low initial densities (25 y 50 g m-3), to 8.3-7.7 g shrimp-1 for the other treatments. However, because of the high survival and of the higher initial density, the best biomass yield was with 100 g m-3. The final nitrogen contents of sediment and water were lower than the initial values, and between 36 and 60% of the difference was converted into shrimp biomass.<br>Durante 40 días se cultivaron juveniles de camarón blanco Litopenaeus vannamei con un peso individual de 3,5 ± 0,3 g y biomasas iniciales de 25, 50, 75 y 100 g m-3 (equivalente a 8-32 ind m-2), sin cambios de agua y adición de alimento, para determinar la tasa de crecimiento usando como única fuente de alimentación el perifiton desarrollado en sustratos artificiales. Se utilizaron estanques cilíndricos de polietileno de 1 m³ con tres réplicas por tratamiento, con una superficie de 4,8 m² (paredes y fondo) y 7,1 m² de sustrato artificial (Aquamats&#8482;). No se encontraron diferencias significativas entre las concentraciones de amonio (0,17-0,19 mg L-1) y nitrito (0,10-0,11 mg L-1) determinadas en los cuatro tratamientos. La supervivencia fue similar, variando entre 91 y 97%. La ganancia en peso individual fue significativamente mayor en los tratamientos con menor biomasa inicial (25 y 50 g m-3), aunque por la mayor densidad inicial, el mejor rendimiento en biomasa se observó en los cultivos sembrados con 100 g m-3. Los contenidos de nitrógeno determinados al final del experimento, en el agua y sedimento, fueron inferiores a los valores iniciales, y entre el 36 y 60% de sus diferencias se recuperaron en biomasa de camarón.

This work presents a general mathematical programming model for satisfying water, energy, and food needs in isolated and low-income communities involving different process integration approaches. The problem consists in determining the optimal and sustainable configuration to satisfy the energy, water, and food demands of the inhabitants. Also, the use of waste-to-energy technologies is proposed to handle the municipal solid waste correctly and obtain valuated products from wastes to reduce the environmental impact. A multiobjective analysis is presented considering the consumption of fresh water, the greenhouse gas emissions, and the cost of the integrated system as objective functions. As a case study, the community with the lowest index of poverty and marginalization from the State of Guerrero in Mexico is presented. The results show that it is possible to satisfy the water, energy, and food needs in isolated communities accounting for integrated processes. Besides, it is possible to obtain trade-off solutions considering contradicting objectives.

Using water-energy-food-environment (WEFE) nexus as the prism, this review explores evolution of groundwater governance in Iran, Saudi Arabia, Mexico, China, Bangladesh and India – which together account for two-thirds of the global groundwater-irrigated area. Global discourse has blamed widespread water scarcity squarely on supply-side policymaking and advocated a broader template of water governance instruments. Integrated Water Resources Management (IWRM) presented just such a template – with pricing, participation, rights and entitlements, laws, regulations, and river basin organizations – as additional water governance tools. However, the IWRM template faced disillusionment and pushback in many emerging economies. WEFE nexus, the new paradigm, prioritizes system-level optima over sectoral maxima by harnessing synergies and optimizing trade-offs between food, water, energy, soil, and eco-system sustainability within planetary boundaries. Realizing this vision presents a complex challenge in groundwater governance. Global groundwater economy comprises three sub-economies: (a) diesel-powered unregulated, as in Nepal terai, eastern India, Bangladesh, Pakistan Punjab and Sind, and much of Sub-Saharan Africa, where use-specific energy subsidies are impractical; (b) electricity-powered regulated, as in North America and Europe, where tubewells are authorized, metered and subject to consumption-linked energy charges; and (c) electricity-powered unregulated, as in geographies covered by our review – barring China, Bengal and Bangladesh – where unmeasured electricity subsidies have created a bloated groundwater economy. This last sub-economy represents the heartland of global groundwater malgovernance, least equipped to meet the sustainability challenge. It has an estimated 300 million horsepower of grid-connected electric pumps that are either unauthorized and/or unmetered and/or use free or heavily subsidized or pilfered power for irrigating 50–52 million hectares, nearly half of global groundwater-irrigated area. In (a) and (b), groundwater scarcity inspires water-energy saving behavior via increased energy cost of pumping. In sub-economy (c), users are immune to energy costs and impervious to groundwater depletion. Here, the WEFE nexus has remained blind to the irrigation realpolitik that catalyzes or constrains policy action. We explore why the political costs of rationalizing subsidies are prohibitive and exemplify how a smart transition from fossil to solar energy for pumping may offer an opportunity to turn the perverse WEFE nexus into a virtuous one.

BACKGROUND: Poor quality irrigation water is a major cause of disease transmission for urban inhabitants consuming fresh produce in many developing countries. Irradiation of food is an alternative approach to reducing health risks for consumers, but its implementation depends heavily on consumer acceptance.RESULTS: In this pilot study, we show that most respondents consider the water quality of Mexico City to be poor and a health risk, and would be willing to pay for irradiated food as a means of pasteurizing fresh iceberg lettuce.CONCLUSION: Irradiated food could, potentially, be accepted in developing countries that have problems with water quality. Such acceptance would presumably be due to the perception that such a novel technology would (1) alleviate water impairment, and (2) lead to economic improvement. It is then possible that the public considers that water quality is a more pressing concern than any potential side effects of food irradiation.

The International Commission on Irrigation and Drainage (ICID) has organized its 23ʳᵈ International Congress in Mexico City during the period 08–‐14 October 2017. Its overall theme was: Modernizing Irrigation and Drainage for a new Green Revolution. Two Questions 60 and 61 were addressed and concerned respectively the following issues: Question 60 on Water Productivity: Revisiting the concepts in light of water, energy and food nexus, and Question 61 on State of knowledge of irrigation techniques and practicalities within given socio‐economic settings. The present paper aims at giving a summary of the main axis covered by the various contributions on Question 60. In fact, 91 contributions from 27 countries analyzed and discussed the three following sub themes related to Question 60, namely: i) Emerging issues and challenges of water saving, including impact of transferring water out of agriculture; ii) Understanding water productivity, water and energy use efficiency and water footprint of crops; iii) Water security for growth and development. A summary of the main ideas and findings emerged, for each sub theme mentioned above, are herein presented. Majors conclusions and recommendations are also included at the end of this paper. © 2019 John Wiley & Sons, Ltd.

As befits a CGIAR Challenge Program , the CPWF has welcomed a wide range of stake holders and partners in accord with their ability to achieve program goals. Decision on research investments (project selection) have been based on a competitive grants in which proposal quality was evaluated by an interdependent external panel. The usual weakness of a competitive grants approach - lack of coherence in research agenda has been address by Basin Focal Projects and synthesis research.

Security of the Water-Energy-Food Nexus has become a global concern, threatened by the rapid urbanization, unsustainable consumption of resources, population growth and climate change that exert pressure on resources to meet the socioeconomic demands. Water-Energy-Food Nexus is central for sustainable development and promoting efficient management of resources. Nevertheless, an efficient and sustainable Water-Energy-Food Nexus design requires the participation of multiple stakeholders in the decision-making process. This work presents a multi-objective optimization model for the design of a Water-Energy-Food system that involves the sustainable production of water, energy and food in areas that share economic activities through the industrial, agriculture and livestock sectors. Additionally, a multi-stakeholder assessment is presented to generate a set of solutions, where different priorities are given to the stakeholders. This approach allows quantifying the level of satisfaction of each of the stakeholders. Integration of resources is addressed according to economic and environmental objectives, such as the minimization of the cost of the system, water abstraction and greenhouse gas emissions. As case study, a region located in Mexico was selected based on its industrial activity and the challenges it currently faces in meeting resource demands due to low water availability. Results show that water reuse is crucial to improve the Water-Energy-Food Nexus sustainability. Also, it was found that the most affected sector for water scarcity is the agricultural sector. This model can be the basis for planning the Water-Energy-Food Nexus at regional level involving different stakeholders and for determining sustainable interactions between resources.

Waste water from Mexico's largest food processing industrial sector (based on maize, nejayote water) was used for growing Brachionus calyciflorus isolated from Lake Chapultepec in the Federal District of Mexico (D.F.). Nejayote water was collected from Colonia Providencia, D.F. Experiments were conducted at 25°C in 25 ml capacity vials with 20 ml of medium into which we introduced B. calyciflorus at an initial density of 1 ind ml-1. The experimental design consisted a total of 33 test vessels (2 food combinations X 5 densities X 3 replicates = 30 plus 3 replicates as controls that contained only algae). Experiments were terminated after day 16. Waste water in original concentration did nt rotifes. However, when diluted to 5 oncentrations (ranging from 2% to 32% and pH adjusted to 7.0), rotifer density increased with increasing concentration of waste water. Green algae (at constant density of 2 X 10 6 cells-1 of Chlorella) in combination with waste water resulted in a higher abundance of rotifers only at higher concentration (above 8 %) of waste water. The maximum peak density of rotifers (238-50 ind ml -1) was obtained at 16% dilution of waste water nd with addition of Chlorella. The rate of population increase per day ® (mean-SD) varied from 0.355-0.059 to 0.457-0.048 depending on food combination and concetration.<br>Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calyciflorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calyciflorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 10(6) células ml-1. Concentraciones de nejayote por encima del 8% no permitieron el crecimiento poblacional. Sin embargo, la presencia de alga permitió el desarrollo del rotífero a concentraciones de 8% y 16%. Nuestros hallazgos indican que el nejayote puedo ser utilizado de manera efectiva para la producción de rotíferos a gran escala para la acuacultura.