This study optimizes the production of activated carbons from hydrothermally carbonized (HTC) biomass using potassium hydroxide (KOH) and phosphoric acid (H3PO4) as activating agents. A 23 factorial experimental design evaluated the effects of agent-to-precursor ratio, dry impregnation time, and activation duration on mass yield and iodine adsorption capacity. KOH-activated carbons achieved superior iodine numbers (up to 1289 mg/g) but lower mass yields (18–35%), reflecting enhanced porosity at the cost of material loss. Conversely, H3PO4 activation yielded higher mass retention (up to 54.86%) with moderate iodine numbers (up to 1117.3 mg/g), balancing porosity and yield. HTC pretreatment at 190 °C reduced the ash content, thereby enhancing the stability of hydrochar. These findings highlight the trade-offs between adsorption performance and process efficiency, with KOH suited for high-porosity applications (e.g., water purification) and H3PO4 for industrial scalability. The study advances biomass waste valorization, aligning with circular economy principles and offering sustainable solutions for environmental and industrial applications, such as water purification and energy storage.
The 2023–2024 blackouts in Quito, Ecuador, led to severe air quality deterioration, primarily driven by diesel generator use and increased vehicular traffic. This study analyzed data from seven urban and peri-urban monitoring stations, applying meteorologically normalized data and machine learning models (Boosted Regression Trees and Random Forests) to isolate the direct impact of blackouts on pollutant concentrations. The results revealed that PM10 increased by up to 45% and PM2.5 by 30%, frequently exceeding regulatory limits, particularly in industrial and residential zones. SO2 exhibited the most extreme rise, surging by 390%, with peak values reaching 500 µg/m3 in areas heavily reliant on high-sulfur diesel generators. The NO2 concentrations exceeded 200 µg/m3 in high-traffic areas, while O3 showed dual behavior, decreasing in urban cores due to titration effects but increasing by 15% in suburban valleys, driven by photochemical interactions. A comparison between 2023 and 2024 blackouts highlighted worsening pollution trends, with longer (8–12 h) outages in 2024 causing severe environmental impacts. The findings demonstrate that blackouts significantly worsen air quality, posing critical public health risks. This study underscores the urgent need for policy interventions to mitigate the environmental impact of energy disruptions. Key recommendations include stricter fuel quality standards, diesel generator emission controls, and an accelerated transition to renewable energy. These results provide scientific evidence for future environmental regulations, supporting sustainable air quality management strategies to minimize future energy crises’ health and ecological consequences.
This study examines the evolution of the scientific literature on mining and heavy metals, with a particular focus on biosanitary risks associated with childhood exposure. The research integrates a systematic literature review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology, combined with a bibliometric analysis of Scopus-indexed publications, international epidemiological data, and an evaluation of the socio-environmental context in Ecuadorian mining regions. The PRISMA-based screening process was applied to identify, filter, and select relevant peer-reviewed studies, enabling the delimitation of a focused corpus of literature, with particular attention given to scientific contributions produced by Latin American researchers and institutions. The results reveal a significant concentration of knowledge production among a limited number of countries and institutions, the dominance of English as the main language of scientific communication, and the centrality of journals in environmental sciences and toxicology. While notable progress has been made in identifying contaminants and exposure pathways, governance structures, territorial disparities, and policy implementation processes remain insufficiently explored. In Ecuador, the rapid growth of mining concessions in ecologically sensitive zones presents potential threats to children’s neurocognitive development, highlighting the urgent need for ongoing surveillance, biomonitoring programs, and preventive public health measures. The study emphasizes the importance of strengthening regional research capacity and fostering more equitable international scientific collaborations to ensure that knowledge production is responsive to local contexts and effectively safeguards vulnerable populations.