Zeolitic tuff constitutes a technical and economical feasible alternative to manage acidic waters in initial phases of generation. A study of cation exchange with two zeolitic tuffs from Ecuador and one from Cuba has been conducted using breakthrough curve methodology. Cations Mn²⁺, Cd²⁺, Cr³⁺, Zn²⁺, and Al³⁺ have been chosen owing to their presence in underground water in exploration activities (decline development) in Fruta del Norte (Ecuador). Zeolites characterized by X-ray diffraction and thermal stability after heating overnight as heulandites show a similar exchange behavior for the five cations studied. The clinoptilolite sample Tasajeras shows a relevant cation exchange performance expressed in the important increment of spatial time to reach the breakthrough point in comparison with heulandite samples. The maximum length of unused beds was found for Cr³⁺ and Zn²⁺ cations showing, therefore, a lower adsorption performance in relation with Mn²⁺ and Cd²⁺. A final disposal method of metal-loaded zeolites with cement is proposed.

Geostatistics is a discipline that deals with the statistical analysis of regionalized variables. In this case study, geostatistics is used to estimate geoid undulation in the rural area of Guayaquil town in Ecuador. The geostatistical approach was chosen because the estimation error of prediction map is getting. Open source statistical software R and mainly geoR, gstat and RGeostats libraries were used. Exploratory data analysis (EDA), trend and structural analysis were carried out. An automatic model fitting by Iterative Least Squares and other fitting procedures were employed to fit the variogram. Finally, Kriging using gravity anomaly of Bouguer as external drift and Universal Kriging were used to get a detailed map of geoid undulation. The estimation uncertainty was reached in the interval [-0.5; +0.5] m for errors and a maximum estimation standard deviation of 2 mm in relation with the method of interpolation applied. The error distribution of the geoid undulation map obtained in this study provides a better result than Earth gravitational models publicly available for the study area according the comparison with independent validation points. The main goal of this paper is to confirm the feasibility to use geoid undulations from Global Navigation Satellite Systems and leveling field measurements and geostatistical techniques methods in order to use them in high-accuracy engineering projects.

The organic composition of 65% of urban solid waste of the Metropolitan District of Quito originates from food waste, which has negative environmental effects. The purpose of this study was to evaluate the factors related to food waste in homes in the capital and characterize urban solid waste management. The study is quantitative and exploratory. An association analysis was performed for the main categorical variables through calculation of statistical chi squared and an assessment of polychoric relation. A descriptive and multi-scale statistical analyses were performed for focus of the social metabolism to characterize waste management. A noteworthy element was the relation between expenses for purchase of food and non-alcoholic beverages in the last month-household income in the last month (p value < 5%). Between 2012-2021, the most representative median for waste generation corresponded to the Eugenio Espejo administration, with 141470 t/ year, with a metabolic waste rate of 2.45E-05 (t/year). On the other hand, the Tumbaco administration obtained 30217 t/year and 1.22E-05 t/year, respectively.

Food insecurity persists in Ecuador, and organizations like the Quito Food Bank (BAQ) are key to mitigating it. This study evaluatesBAQ’s management from a sustainability perspective, analyzing its social, economic, and environmental impacts in line with the Sustainable Development Goals (SDGs). A mixed, exploratory, and descriptive case study approach was employed. Data collection included direct observation, a review of internal records, and semi-structured surveys administered to 240 volunteers. The environmental impact was quantified using a “gate-to-gate” Life Cycle Assessment (LCA) with OpenLCA software and the ReCiPe 2016 methodology, while The social and economic analysis was conducted in R, using non-parametric statistical tests. The LCA identified storage as the main critical environmental, responsible for over 80% of the impacts due to high-energy consumption for refrigeration. Socially and economically, the BAQ’s food basket provides significant savings for beneficiary households, allowing them to redirect resources to other essential needs. However, this assistance is only partial and does not generate full economic security. The study highlights the duality of the BAQ’s operations: while food redistribution generates social and environmental benefits by reducing waste, it has its own environmental footprint due to the use of energy resources. A more holistic perspective is therefore proposed to ensure these interventions are truly sustainable in the long term.