El objetivo general de este trabajo fue encontrar un nuevo valor agregado a las hojas de las agaváceas, desecho de la agroindustria. Se estudiaron cuatro especies de agaves de tres estados de la república mexicana: Agave angustifolia (Oacaxa), Agave tequilana (Jalisco), Agave salmiana y Agave lechuguilla (Hidalgo). Luego de una clasificación taxonómica, fenológica, ecológica y etnobotánica (basados en morfología comparada), se sometieron a diversos análisis físicos (humedad, molienda, tamizaje, granulometría y características foliares, MEB) y químicos (cenizas grasas y aceites, proteínas, análisis TGA y DTGA, así como FTIR). Las especies de A. angustifolia y A. tequilana son las que presentan un óptimo tamaño de fibra para la elaboración de papel. Corresponde también a los mayores porcentajes de celulosa (44.3% y 36.8%) por DTGA. Del análisis proximal, se evidencia que las dos especies definidas como mejores para la obtención de pulpa de celulosa, presentan pequeñas diferencias significativas en contenidos de grasas, proteínas, material solubilizable en agua caliente (AT) como en solución moderadamente alcalina y/o alcohólica.

Socio-environmental conflicts are situations that exemplify human rights transgressions caused by extractive activities. These are present in developing countries where extractivism, imperialism, and colonialism paradigms prevail. In the context of Mexico, criminalization, violence, and the absence of rule of law promote these conflicts, frequently aggravated by involvement with private interests. In the last 20 years, the relationship between human rights in the mining sector and its impact on the environment has been a critical research subject. This paper aims to carry out a systematic review to analyze human rights transgressions related to the mining industry’s impact in Mexico, and identify factors causing socio-environmental conflicts. The current study shows a systematic analysis based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. This method contributed to the collection of references that describe conflicts due to human rights transgressions and environmental damage in mining areas in Mexico. Human rights transgressions caused by mining in a Mexican context demonstrate the inability of the state to stop the increase in socio-environmental conflicts and its lack of concern towards preventing damage to the environment.

Chromium (Cr) is an element present in nature in mineral form. It has a dual effect, both as an essential micronutrient and a carcinogenic agent depending on its chemical form and concentration. It is present in various environmental matrices such as water, soil, and air, coming from natural and anthropogenic sources, and causes harmful effects on biota, ecosystems, and even human beings. This study's objective was to evaluate chromium toxicity and teratogenicity in zebrafish embryos of Danio rerio exposed to chromium through the D. rerio teratology assay (DarTA) test by evaluating spine malformations. To this end, the chromium toxicity curve was calculated from zebrafish embryos exposed to potassium dichromate (K2Cr2O7), and the probit test was used to establish the mean lethal concentration (LC50) and three subtoxic concentrations LC25, LC12.5, and LC6.25 to evaluate the teratogenicity. The results showed that potassium dichromate was statistically positive for the teratogenic effect at the three highest concentrations evaluated. Potassium dichromate exposure causes abnormal embryonic development and teratogenic effects, including severe heart defects in zebrafish embryos. Therefore, we conclude that potassium dichromate is toxic to the zebrafish developmental stages. The finding that potassium dichromate is teratogenic in zebrafish embryos suggests that this metal should be tested and evaluate potential risk in mammalian systems.

Arsenic contamination in groundwater has been detected in several studies in the region of Zimapan, Mexico. Arsenic contamination sources have been reported as natural and anthropogenic. In this study, the variation in concentrations of pollutants in mineralized zones, sedimentary rocks and anthropogenic activities was determined. Arsenic and lead concentrations of 5.0–248.0 and 0.10–132.0 μg L⁻¹ were observed in groundwater, respectively. Water mineralization was medium to medium high. Conductivity values between 198.0 and 970.0 μS cm⁻¹ were determined. Some contaminated wells showed conductivity values as much as 1,700 μS cm⁻¹. Open wells near mining waste showed conductivity values up to 1,485.0 μS cm⁻¹. Groundwater showed neutral pH and alkalinity tendency. Arsenic concentrations were low in the volcanic aquifer, and high in the aquifer with carbonate rocks. The average total arsenic concentration was 47.8 μg L⁻¹. Arsenic concentrations of 20–100 μg L⁻¹ were observed in 93% of the sampled points; concentrations greater than 50 μg L⁻¹ were found in 20% of the total. Forty-seven percent of the evaluated points correspond to samples associated with carbonate rocks.

Anode (Al and Fe) and cathode (graphite and Ti/RuO2) materials have been tested for electrocoagulation (EC) and purification of the acid whey. The electroactive areas (EA) of electrodes were calculated by the double layer capacitance method. Experiments were performed by cyclic voltammetry, chronoamperometry and polarization experiments. Among cathodic materials, the Ti/RuO2 electrode showed higher EA (2167 cm2) than graphite (1560 cm2). The Fe anode was found more stable than Al with greater charge transfer carried out in less time. Correlation of these results with those obtained during preliminary tests confirmed high removals (79 %) in 8 h. For the Al electrode, 24 h were required to achieve efficiency of 49 %.