During its journey, the river water suffers natural or anthropic contamination, deteriorating its quality.  This impact can be qualified by determining the pollution Indexes (IPO). The work aimed to evaluate the spatial and temporal variation of the IPOs in the water of the high Andean micro-basin of the Chumbao River. The study included the section from 13°46'38.4” S, 73°15'32.3” W at 4079 m of altitude up to 13°35'26.4” S, 73°27'00.8” W at 2572 m of altitude. Physical, chemical, and microbiological parameters of the water were determined in 8 points along the river. These were grouped to calculate the IPO by mineralization (IPOMI), organic matter (IPOMO), suspended solids (IPOSUS), and trophic (IPOTRO) in the dry and rainy seasons. The indexes were categorized from 0.0 (not polluted) to 1.0 (highly polluted). The data were collected in triplicate and valuated through ANOVA and Tukey's test. It was found that IPOSUS, IPOMI, and IPOMO. The points near the head of the micro-basin reported no and low pollution; besides, they increased considerably in urban areas reaching highly polluted levels. In contrast, IPOTRO reported a eutrophic state, and that contamination levels were higher in the dry season. The waters of the Chumbao River above 2900 m of altitude and close to the head of the micro-basin do not show contamination, but in the urban area the index of pollution is high.

Los metales se transportan, a nivel espacial y temporal, a través de la superficie del suelo y la atmósfera, convirtiéndose en un peligro para el medio ambiente y poblaciones vulnerables de las cuencas hidrográficas. El presente estudio tuvo como objetivo determinar fuentes y niveles de metales en sedimentos del agua en la microcuenca del río Huancaray en la región Apurímac (Perú), mediante la técnica de análisis por fluorescencia de rayos X (FRX) durante la época de secas y lluvias de los años 2018 y 2019. Los elementos detectados fueron K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Br, Rb, Sr, Y, Zr, Nb y Ba. Resalta la presencia de Zn, Cr, Cu, Pb, Ni y As como elementos críticos en cada punto de la microcuenca del río Huancaray; las concentraciones son superiores a los límites permisibles; asimismo, los periodos de lluvia y seca no presentan diferencia significativa, mientras que las principales fuentes de contaminación son centros poblados, prácticas de la agricultura, presencia de la minería ilegal y fuente de origen natural.

The avocado fruit is an agro-industrial product with high export demand in Peru due to its sensory and nutritional qualities, which can be affected during storage. The study aimed to evaluate the effect of the application of a coating formulated with potato starch (Solanum tuberosum ssp andigena), nopal mucilage (Opuntia ficus indica), and pectin on the physicochemical and physiological properties during the storage of Fuerte and Hass avocados. Samples were taken in their harvest state from the plantation in “Occobamba”, which is cultivated by the Avocado Producers Association in Chincheros, Apurímac, Peru. Physicochemical properties (titratable acidity, pH, total soluble solids) and physiological properties (weight loss, firmness, and color L* a* b*) were determined during 20 days of storage at 20 °C. The elaborated films present high transparency and low aw values. In the coated avocado of the Hass and Fuerte varieties, acidity and total soluble solids decreased significantly (p-value < 0.05) during the storage time. Weight loss and firmness of coated fruits decrease to a lesser extent. Luminosity L*, color index, and color variation showed better attributes for the coated samples. The use of coatings made with potato starch, nopal mucilage, and pectin allows the physicochemical and physiological properties of avocado fruits to be maintained for a longer time during storage.

The removal of heavy metals from wastewater is an environmental challenge which demands the use of environmentally friendly materials that promote a circular economy. This study aimed to apply a novel composite of an activated nanoclay/hydrocolloid in the removal of heavy metals from wastewater. A composite blended under pressure was prepared with spray-dried hydrocolloid derived from Nostoc sphaericum algae and activated nanoclay in an acid medium and 1M NaCl. The composite and components were analyzed through infrared (IR), X-ray (XR), ζ potential, cation exchange capacity (CEC), particle size, and SEM images. The composite was subjected to the adsorption of heavy metals (Pb, As, Zn, and Cd) at pH 4.5 and the removal percentage, kinetics, and adsorption isotherms were evaluated. It was observed that the activated nanoclay and the composite that presented a particle size of around 400 nm significantly increased (p-value < 0.05) the CEC, ζ potential, the functional groups, and chelating components, removing heavy metals above 99% for Pb, As 33%, Cd 15%, and Zn 10%. Adsorption kinetics was adjusted to the pseudo second-order model (R2 > 0.98), and the Langmuir and Freundlich models better represented the sorption isotherm at 20 °C. The formulated composite presents a good ability to remove heavy metals in wastewater.

The spatial and temporal quantification of climatic elements is necessary in different regions of the world, as mitigation policies against climate change in recent years the use of renewable energies has been promoted, with solar radiation being an important element, the objective is to correct Tropical Rainfall Measuring Missions (TRMM) satellite data series of solar radiation with respect to the data observed through an automatic meteorological station for a short period at a point located in the southern Peruvian Andes, we proceeded to process the observed data and download satellite information, making use of From a mathematical model, the correction coefficients of the satellite data were determined; The multiplicative factor model better corrects the satellite information, the Pearson correlation improved from R = 0.65 to R = 0.84 for monthly solar radiation, in the series of satellite data corrected for 37 years, a trend was determined -0.0006 Watt/m2/month.