La transformación del nitrógeno en la bosta de caballo (BC) y en el rastrojo vegetal con estiércol de vaca (VR) en todas las etapas del compostaje de estos residuos. Objetivo. Evaluar el comportamiento del nitrógeno en el compost de la bosta de caballo comparándolo con lo sucedido en el compost del rastrojo vegetal con estiércol de vaca. Materiales y métodos. Uso de pilas de compostaje a cielo abierto y la evaluación físico química del proceso. Resultados. En ambas pilas de compostaje la temperatura alcanza su mayor valor en la fase termofílica dentro de la primera semana. Los valores de pH se están regulados por la formación y volatilización del nitrógeno amoniacal. La conductividad eléctrica del compost producido por la bosta de caballo alcanza un valor máximo de 5 uS/cm y el producido por el rastrojo vegetal con estiércol de vaca de 4 uS/cm esto se relaciona con la formación de nitrógeno amoniacal en la fase termofílica y nitratos en la fase de enfriamiento. La relación C/N al final del compostaje para la bosta de caballo se incrementa, debido a que solo queda residuos de cascarilla de arroz no degradado. La disminución de la concentración de N-NH4 es debido a volatilización y formación de N-NO3. Conclusiones. El compost de la bosta de caballo presentó una mayor concentración de nitrógeno que el compost del rastrojo vegetal con estiércol de vaca.

El presente estudio evalúa la variabilidad hidroquímica del río Asana por influencia de la quebrada Millune en Moquegua, Perú. Se analizó la información de monitoreos de calidad de agua durante el periodo 2010-2018 a través de los diagramas de Gibbs, las relaciones molares, el diagrama de Piper, el diagrama de Stiff y el modelo hidrogeoquímico PHREEQC para la identificación de los índices de saturación de los principales minerales a los que están expuestos los cuerpos de agua en evaluación. El análisis por componentes principales permitió la identificación de la variabilidad de la hidroquímica en función de la naturaleza de la fuente y su estacionalidad. Los resultados obtenidos muestran que las aguas de la quebrada Millune, afluente del río Asana, son de naturaleza ácida con presencia de iones de aluminio y manganeso en concentraciones elevadas respecto a lo establecido en el ECA agua (estándar de calidad ambiental de agua), a diferencia del río Asana, que presenta concentraciones bajas; ambos ríos son de naturaleza sulfatada cálcica. Se determinó que los iones aluminio y manganeso se deben a la meteorización del mineral alunita y erosión del suelo, aporte mineral, por el deshielo paulatino del nevado Arundani, ubicado en la cabecera de cuenca del río Asana. Finalmente, el río Asana, por su capacidad de amortiguamiento, neutraliza las aguas ácidas y disminuye la solubilidad de los cationes disueltos.

The Peruvian anchoveta fishmeal industry generates wastewater (pumping water) during the transport of fish from boats to production plants. This study represents the first evaluation in Peru of Moringa oleifera (MOD) and chitosan as bio-coagulants specifically applied to the coagulation–flocculation treatment of pumping water, providing a direct comparative analysis against traditional ferric sulfate under identical experimental conditions. The effluent is characterized by an extreme turbidity of 5,683 NTU, total suspended solids (TSS) at 3359.3 mg/L, and oils and fats at 451.3 mg/L, and it was treated using optimized doses: 4.0 g/L for MOD and 0.2 g/L for chitosan. The results demonstrate that natural alternatives achieve turbidity removal exceeding 97.5%, matching the efficiency of inorganic salts. Notably, chitosan achieved 88.59% TSS removal with no significant statistical difference (p > 0.05 according to the Kruskal–Wallis test) from ferric sulfate, while MOD excelled in oil reduction (37.84%) compared with chitosan. Beyond treatment efficiency, this research fills a gap in circular economy data by identifying that the resulting sludge, containing >4% non-toxic nitrogen, is suitable for composting. These findings establish a new renewable benchmark for the Peruvian fishing industry’s transition toward sustainable, zero-waste water management.

The preservation of hydrobiological diversity is essential to ensuring the stability of the food chain and the sustainable development of high-Andean basins, which face increasing vulnerability to anthropogenic factors such as the construction of dams and reservoirs. In this study, multiple regression models, both linear and nonlinear, were developed to predict the Shannon–Wiener (H′) and Pielou (J′) indices of periphyton and macrobenthos using 21 water quality parameters and concentrations of nine metals in sediments. Samples of macrobenthos and periphyton were collected at seven monitoring stations during the dry and wet seasons between 2014 and 2025. For the analysis, linear regression models were compared with nonlinear machine learning models, specifically Gradient Boosting and Random Forest. Principal component analysis (PCA) revealed that variability of the basin’s ecosystem is dominated by geogenic factors (conductivity, boron, chlorides, and arsenic) and thermal influence. The Gradient Boosting model demonstrated superior predictive capacity (R² = 0.768 for macrobenthos) compared to linear models (R² = 0.354), successfully capturing the nonlinear responses of biota to stressors such as arsenic in sediments and temperature. It is concluded that natural chemical anomalies in the Titire River act as severe ecological filters, and that artificial intelligence shows promising results in the exploration of new applied tools for environmental management in extreme altoandine ecosystems.

Non-marketable postharvest residue from Satsuma Owari mandarins (Citrus unshiu)—discarded due to having a puffy peel (MC) or being damaged (MD)—was evaluated against a commercial mature reference (MM) using an integrated cascade biorefinery. Along the liquid pathway, must fermentation (6.1–9.0% v/v) and fractional distillation yielded a citrus brandy (~30% v/v). Vinasse emerged as the stream of highest strategic relevance, maximizing bioactive response (up to 1339.1 µg GAE/mL) with a naringenin-dominated phytochemical profile. Along the solid pathway (peel), sequential recovery of essential oil and pectins was performed. Essential oil yields (0.575–0.85 mL/100) decreased significantly with physical peel damage, underlining flavedo integrity. Concurrently, recovered pectins (18.6–23.3%) exhibited a degradation-driven structural transition: MM retained galacturonic acid-rich linear domains (89.8%), whereas in MD they had evolved toward a branched architecture with higher rhamnogalacturonan I (30.6%). All fractions were low-methoxyl (DM < 50%), ensuring functionality in ionic gelling systems. In conclusion, this reproducible strategy successfully transforms postharvest losses into functional ingredients and chemical distillates, providing a robust foundation for circular economy models within the citrus industry.