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.

A green vortex assisted based liquid-liquid microextraction (VA-LLME) method was developed for preconcentration of selenium. Ammonium pyrrolidine dithiocarbamate (APDC) was used to form a hydrophobic complex with selenium in natural water, agricultural soil and food samples by GFAAS. Whereas Triton X-114, a nonionic surfactant and 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid were used for Se extraction as a dispersing medium. The conical flasks contents were shack on a vortex mixer to increase the extraction efficiency. Multivariate techniques were used to evaluate extraction parameters; pH, vortex time, APDC amount, volume of ionic liquid and Triton X-114 and centrifugation rate on the recovery of Se. The central composite design (CCD) was used for further optimization of the essential extraction parameters. The enhancement factor and limit of detection were obtained as 98.7 and 0.07 µg L⁻¹. The certified reference materials was used for accuracy of method and the related standard deviation was found to be 3.51%. The resulted data indicated that concentrations of Se in all types of water samples were below the permissible limit recommended by WHO.