11 research outputs found
Variación temporal y espacial de la columna total de ozono en la región andina del Perú, santiago de Chile y en la Antártida 2005-2020
Se describirá los resultados del estudio de la columna total de ozono obtenidos con el sensor OMI del satélite AURA durante el periodo 2005-2020. Por ello el presente proyecto de investigación es de fundamental importancia, para estimar o cuantificar la variabilidad temporal del ozono total y dar a conocer a la población o comunidad científica para su comprensión y entendimiento
El jengibre y su relación con el comercio exterior en la economía peruana 2010 - 2019
Ginger (Zingiber officinale), better known as kion, has become an emblematic product of the exportable offer, with advantages and functional properties that are highly appreciated in the international market, with very notable official figures in 2019, placing Peru as the fourth exporting country world with 23.4 thousand tons and 41.5 million US . El objetivo del presente trabajo de investigación fue determinar la influencia de la exportación del jengibre, en comercio exterior en la economía peruana en el período 2010 – 2019; para ello se analizó el desenvolvimiento de las exportaciones del jengibre, así como su tendencia, relacionándolo con el comportamiento del Producto Bruto Interno y del PBI Agropecuario, utilizando fuentes secundarias. El estudio de nivel descriptivo y correlacional evaluó la significativa relación entre indicadores, haciendo uso de métodos deductivo e inductivo. Luego del análisis correspondiente, se logró determinar una alta correlación entre las exportaciones del jengibre y las exportaciones totales (R2 = 0.6794); como también con las exportaciones no tradicionales (R2 = 0.7296); de manera similar, una alta relación con el crecimiento de nuestra economía, que se evidencia en la correlación con el Producto Bruto Interno Nacional (R2 = 0.7971); y, el Producto Bruto Interno Agropecuario (R2 = 0.6885). Se concluye que, la exportación del jengibre constituye un factor importante en el crecimiento del comercio exterior en la economía nacional
Remoción de Cu (II) de aguas ácidas usando biomasa de las cáscaras de coco
Conferencia de la 20th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Education, Research and Leadership in Post-pandemic Engineering: Resilient, Inclusive and Sustainable Actions”. hybrid event, Boca Raton, Florida- USA, junio 18 - 22.La contaminación del agua por metales pesados generados por la industria minera es un problema ambiental. El uso de materiales de desecho orgánicos para tratar estas
aguas ofrece una alternativa a las tecnologías de tratamiento existentes.
El presente trabajo de investigación reporta la remoción de cobre de aguas ácidas utilizando biomasa de cáscara de coco (BCC). Las muestras de agua a tratar fueron recolectadas de las redes de drenaje de la laguna de Huascacocha, la concentración de Cu detectada fue de 3,26 mg/L, valor que supera los Estándares de Calidad Ambiental establecidos por la legislación peruana. En un sistema discontinuo se evaluó la influencia del tiempo de contacto y tamaño de partícula del BCC sobre el porcentaje de remoción de Cu (% R). Se logró un % R mayor de 92,67 con un tamaño de partícula de 0,21 mm y un tiempo de contacto de 60 min. Del análisis estadístico se concluye que las dos variables en estudio, a sí como su interacción, influyen significativamente en el % R. De los resultados presentados se puede decir que la BCC es una alternativa ecológica y factible para la remoción de Cu (II ) de aguas ácidas.Campus Huancay
Arabica‑cofee and teobroma‑cocoa agro‑industrial waste biosorbents, for Pb(II) removal in aqueous solutions
Agro-industrial waste biosorbents of arabica–cofee (WCA) and theobroma–cocoa (WCT) have been characterized and tested to remove Pb(II) from aqueous media. The maximum adsorption capacity of WCA and WCT (qmax = 158.7 and 123.5 mg·g−1, respectively) is comparable or even higher than for several other similar agro-industrial waste biosorbents reported in the literature. Structural and morphological characterization were performed by infrared spectrometry with Fourier transform (FT-IR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and charge measurements at the zero point charge (pHPZC). Both biosorbents, WCA and WCT, show cracked surfaces with heterogeneous plates which ones include functional adsorption groups such as OH, C = O and C-O-C. Optimal Pb(II) adsorption occurs for a pH between 4 and 5 at [WCA] and [WCT] dose concentrations of 2 g·L−1. We found that the adsorption process follows pseudo-second order kinetics with a rapid growth rate (almost six times larger for WCA than for WCT), basically controlled by the chemisorption process. The regeneration of both biosorbents was carried out in an eluent of 0.1M HNO3 and they can be eficiently reused up to 5 times.Campus Lima Centr
Study of lead divalent biosorption from aqueous solutions using corncob biomass modified (Zea mays)
Se estudió la remoción de los iones de Pb(II) de soluciones acuosas utilizando la biomasa del marlo de maíz modificado químicamente con una solución 0,2 M de NaOH, mediante un sistema batch, lográndose incrementar la capacidad de adsorción en un 40% frente a su similar sin modificar (ZM). El marlo de maíz modificado (MZM) se caracterizó por espectroscopía infrarroja con transformadas de Fourier (FTIR) determinándose la presencia de grupos funcionales como OH y grupos carboxílicos los cuales estarían favoreciendo el proceso de biosorción, se determinó el área superficial siendo esta igual a 2,2 m2/g. Asimismo, se evaluó la capacidad de adsorción del MZM en función del tiempo de contacto, dosis del biosorbente, pH y concentración inicial de la solución de Pb (II). Las condiciones óptimas para la remoción de Pb(II) fueron 4g/L de MZM, tiempo de agitación de 60 minutos y pH igual a 5,0. Los datos cinéticos se ajustaron al modelo de Pseudo Segundo Orden, los datos experimentales de equilibrio se ajustaron mejor al modelo Langmuir, lo que indicaría una biosorción en monocapa. El MZM posee una capacidad máxima de biosorción de 12,44 mg/g
Efficient Lead Pb(II) Removal with Chemically Modified Nostoc commune Biomass
A new biosorbent based on Nostoc commune (NC) cyanobacteria, chemically modified with NaOH (NCM), has been prepared, characterized and tested as an effective biomass to remove Pb(II) in aqueous media. The adsorption capacity of NCM was determined to be qe = 384.6 mg g−1. It is higher than several other biosorbents reported in the literature. Structural and morphological characterization were performed by FTIR, SEM/EDX and point zero of charge pH (pHPZC) measurements. NCM biosorbent showed more porous surfaces than those NC with heterogeneous plates including functional adsorption groups such as OH, C = O, COO−, COH or NH. Optimal Pb(II) adsorption occurred at pH 4.5 and 5.5 with a biomass dose of 0.5 g L−1. The experimental data of the adsorption process were well fitted with the Freundlich-isotherm model and pseudo-2nd order kinetics, which indicated that Pb(II) adsorption was a chemisorption process on heterogeneous surfaces of NCM. According to the thermodynamic parameters, this process was exothermic (∆H0 < 0), feasible and spontaneous (∆G0 < 0). NCM can be regenerated and efficiently reused up to 4 times (%D > 92%). NCM was also tested to remove Pb (%R~98%) and Ca (%R~64%) from real wastewater
Effective Removal of Cd(II) from Aqueous Solutions Using Theobroma cacao Agro-Industrial Waste
Theobroma cacao agro-industrial waste (WTC) has been characterized and tested as an effective biosorbent to remove Cd(II) from aqueous media. At the optimum pH of 5.0, a maximum adsorption capacity of qe,max = 58.5 mg g−1 was determined. The structural and morphological characterization have been conducted by FTIR, SEM/EDX, and TGA measurements. The SEM/EDX results confirmed that the metals are adsorbed on the surface. C-O-C, OH, CH, NH, and C=O functional groups were identified by FTIR. TGA results were consistent with the presence of hemicellulose. Biosorption kinetics were rapid during the first 30 min and then reached equilibrium. The corresponding experimental data were well fitted to pseudo-first and -second order models, the latter being the best. The biosorption isotherm data were also well fitted to Temkin, Langmuir, and Freundlich models, showing that several sorption mechanisms may be involved in the Cd(II) biosorption process, which was characterized as exothermic (ΔH0 < 0), feasible, and spontaneous (ΔG0 < 0). In binary (Cd–Pb and Cd–Cu) and ternary (Cd–Pb–Cu) systems, Cu(II) and particularly Pb(II) co-cations exert strong antagonistic effects. Using HNO3, effective good regeneration of WTC was obtained to efficiently remove Cd(II) up to three times
Biosorption of lead (ii) in aqueous solution with biomass of prickly pear cladodes (opuntia ficus indica)
Se investigó la remoción de plomo de soluciones acuosas por biomasa de los cladodios de la tuna (BCT), una especie abundante en la sierra peruana. Las propiedades físicas y químicas de la BCT se determinaron por técnicas de FTIR y SEM/EDX. El análisis FTIR confirmó la presencia de grupos –OH, CO–C, C=O y –NH2, los cuales interactuarían con el metal. La micrografía SEM reveló que la morfología superficial de la BCT tiene porosidad adecuada para la biosorción. En un sistema discontinuo se obtuvo la más alta capacidad de biosorción (qe) con una relación masa BCT/volumen de 4 g/L, pH 4,5 y tiempo de contacto de 1 h. La biosorción siguió un modelo cinético de pseudo-segundo orden y el proceso de difusión intraparticular fue el factor principal de control de la velocidad. Los datos en el equilibrio fueron correlacionados con cinco modelos (Langmuir, Freundlich, Temkin, D-R y Redlich-Peterson) y se ajustaron mejor al modelo de Langmuir, lo que indica que el proceso se realiza en centros activos energéticamente homogéneos, el valor de qe máxima fue 50,25 mg/g. Los resultados obtenidos demuestran que la BCT puede ser usada como biosorbente eficiente para el tratamiento de aguas contaminadas con Pb (II)
Alkaline Modification of <i>Arabica</i>-Coffee and <i>Theobroma</i>-Cocoa Agroindustrial Waste for Effective Removal of Pb(II) from Aqueous Solutions
Arabica-coffee and Theobroma-cocoa agroindustrial wastes were treated with NaOH and characterized to efficiently remove Pb(II) from the aqueous media. The maximum Pb(II) adsorption capacities, qmax, of Arabica-coffee (WCAM) and Theobroma-cocoa (WCTM) biosorbents (qmax = 303.0 and 223.1 mg·g−1, respectively) were almost twice that of the corresponding untreated wastes and were higher than those of other similar agro-industrial biosorbents reported in the literature. Structural, chemical, and morphological characterization were performed by FT-IR, SEM/EDX, and point of zero charge (pHPZC) measurements. Both the WCAM and WCTM biosorbents showed typical uneven and rough cracked surfaces including the OH, C=O, COH, and C-O-C functional adsorbing groups. The optimal Pb(II) adsorption, reaching a high removal efficiency %R (>90%), occurred at a pH between 4 and 5 with a biosorbent dose of 2 g·L−1. The experimental data for Pb(II) adsorption on WACM and WCTM were well fitted with the Langmuir-isotherm and pseudo-second order kinetic models. These indicated that Pb(II) adsorption is a chemisorption process with the presence of a monolayer mechanism. In addition, the deduced thermodynamic parameters showed the endothermic (ΔH0 > 0), feasible, and spontaneous (ΔG0 < 0) nature of the adsorption processes studied
Single and Binary Removals of Pb(II) and Cd(II) with Chemically Modified Opuntia ficus indica Cladodes
In this study, cladodes of Opuntia ficus indica (OFIC), chemically modified with NaOH (OFICM), have been prepared, characterized, and tested as an effective biomass to remove Pb(II) and/or Cd(II) from aqueous media. At an optimum pH of 4.5, the adsorption capacity, qe, of treated OFICM was almost four times higher than that of untreated OFIC. The maximum adsorption capacities (qmax) in the single removal of Pb(II) and Cd(II) were 116.8 and 64.7 mg g−1, respectively. These values were 12.1% and 70.6% higher than those for the corresponding qmax in binary removal, which indicates the strong inhibitive effect of Pb(II) on the co-cation Cd(II) in a binary system. Structural and morphological characterization have been carried out by FTIR, SEM/EDX, and point of zero charge (pHPZC) measurements. The SEM/EDX results confirmed that the metals are adsorbed on the surface. The presence of C-O, C=O, and COO- functional groups were identified by FTIR on both OFIC and OFICM surfaces. On the other hand, we found that the adsorption processes followed the pseudo-second-order kinetics for both single and binary systems, with a fast biosorption rate of Pb(II) and Cd(II). The equilibrium data (adsorption isotherms) were better described by Langmuir and modified-Langmuir models for single and binary systems, respectively. A good regeneration of OFICM was obtained with an eluent of 0.1 M HNO3. Therefore, OFICM can be efficiently reused to remove Pb or Cd, up to three times