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Antecedentes: la producción de papel está soportada principalmente en la madera debido a su alto contenido de celulosa. Sin embargo, actualmente se buscan fuentes alternativas que desestimulen el uso de este recurso favoreciendo la protección de los recursos naturales. La producción de cacao es una actividad económica importante en Colombia, sin embargo, genera grandes cantidades de residuos orgánicos. La cascarilla de cacao es uno de los residuos más significativos de la industria del cacao y representa alrededor del 12 % del peso total de la semilla. Objetivo: evaluar las propiedades fisicoquímicas del papel obtenido a partir de la cascarilla de cacao de la variedad TCS 01. Métodos: se identificó y cuantificó la composición de celulosa, hemicelulosa y lignina de la cascarilla de cacao. Se realizó un diseño experimental para analizar las condiciones de extracción y elaboración del papel obtenido de la celulosa de la cascarilla y se evaluaron seis parámetros de calidad basado en la norma NTC 5342 (muestreo para determinar la calidad de papel y cartón): adsorción, tensión, escritura, color, textura y apariencia. Resultados: se obtuvo un porcentaje de celulosa, hemicelulosa y lignina de 12,5, 21,5 y 15,6 % en peso respectivamente. A partir del diseño experimental para la elaboración del papel, se observó que a una temperatura de 80°C y durante 8 horas se obtuvo el mejor tratamiento, mostrando las mejores características de calidad y cumpliendo lo requerido por la NTC 5342. Se observó que la masa límite de celulosa fue de 4,21 g de muestra húmeda la cual tuvo una absorción de 3,5 ml de agua. Los ensayos de tensión mostraron resultados de 8,2 N en las muestras de papel. Conclusiones: aunque el material obtenido no cumple a cabalidad con las características necesarias para catalogarse como papel, este material puede ser utilizado en la producción de envases y embalajes donde se requiere resistencia mecánica moderada o en la producción del material llamado “cartón paja”. Además, su alta adsorción medida en la prueba realizada indica que este material podría ser utilizado como absorbente en las industrias alimentaria o de construcción. [ABSTRACT FROM AUTHOR]

Peat is an organic material that has been widely used as an efficient and low-cost adsorbent. As many studies tend to focus on temperate peats, there is a lack of knowledge about the adsorption mechanism of tropical peats. This paper investigates the use of two Brazilian peats (Cravinhos - C and Luis Antônio - LA) from the Mogi-Guaçu river basin for the adsorption of lead (Pb), zinc (Zn), and cadmium (Cd), in order to contribute to the use of local and easy access materials to remediate contaminated sites. The peats adsorbed a high percentage of cations, especially Pb cations (100.0-46.3%), with commercial peat C showing higher adsorption than peat LA. The removal order was Pb2+ > Cd2+ = Zn2+ for C and Pb2+ > Zn2+ > Cd2+ for LA. The batch data for both peats and for all metals were better fit by the Langmuir isotherm, with adsorption capacities (qm) for Pb, Zn, and Cd of 37.3134, 29.0674 and 21.2890 mmol kg-1 in peat C and 21.7391, 14.2550 and 3.6460 mmol kg-1 in LA, respectively, values comparable to those of other peats and biosorbents. The studied peats are considered efficient, alternative and low-cost adsorptive materials for these metals. The proximity of peatlands to areas with high potential for contamination necessitates the use of local materials to reduce remediation costs. [ABSTRACT FROM AUTHOR]

During polymer injection in enhanced oil recovery processes, polymeric molecules are attached to the rock surface as a result of a series of interactions between both components, leading to concentration decrease on the injected batch. This phenomenon, known as adsorption [18], can be estimated by analytical models and depends on several factors like the type of rock, degree of hydrolysis and polymer concentration, reservoir temperature, salinity of formation water, among other aspects. This paper shows the results of 144 statics tests where salinity (NaCl and CaCl2) and polymer concentration were taken as the parameters to be changed in order to determine which analytical model is the most accurate for the prediction of experimental results. The abnormal adsorption tendency with NaCl, indicates that the grater salinity value, the lesser adsorption value concentrations. This is mainly due to the response of the kaolinite substrate to flocculation. [ABSTRACT FROM AUTHOR]

In this paper, the process for the synthesis of LTA and/or FAU zeolites from waste materials from mining and manufacturing industry from Antioquia (Colombia) was described. The product was used as adsorbent for the removal of Cr (III) in solutions prepared in the laboratory. The waste materials were characterized by X-ray fluorescence, and X-ray diffraction. The zeolites were characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscopy (SEM) and BET area. Absorption data in Cr(III) removal tests were obtained by elemental composition from atomic absorption spectroscopy, and evaluated by Langmuir, Freundlich and Temkin models, and four kinetics models. The results showed the formation of zeolites from waste materials, and effective in adsorption tests of Cr (III). [ABSTRACT FROM AUTHOR]

Natural gas contains different types of gases such as methane, ethane, propane, butane, nitrogen and carbon dioxide, which methane is the main component. The separation of carbon dioxide from natural gas makes effective its use as domestic fuel, industrial and automotive fuel. The use of porous materials, which are able of preferentially adsorbing the CO2, is an alternative to obtain pure natural gas that allow the above mentioned applications. The traditionally used materials as CO2 adsorbents are activated carbon, zeolites and metal-organic frameworks (MOFs). In this paper, the CO2 adsorption capacity using zinc oxide nanoparticles (ZnONPs) is evaluated. These materials are attractive adsorbents, due to their low cost and great capacity of functionalization. [ABSTRACT FROM AUTHOR]

In this paper the removal of total organic carbon (TOC) present in an effluent generated by the rendering industry was evaluated, by photocatalysis (photo-Fenton) and activated carbon adsorption. The effluent considered in the study was the condensed steam cooking that has high environmental burdens so conventional biological and chemical treatments are insufficient or are economically unviable. To evaluate the effect of process variables, concentration of Fe (II) and dose of oxidizing agent (H2O2), the response surface methodology was used. In the adsorption study, the effect of pH, adsorbent dose and contact time was considered. For photocatalytic treatment the TOC removal percentage obtained was 69.2%, while for the adsorption process was 77.9%. After that, the TOC removal of two coupled systems was evaluated. For one of the systems, the effluent was pretreated by adsorption and subsequently subjected to photocatalytic treatment, reaching an overall degradation of 91.9%. This synergy between adsorption and photo-Fenton processes appears as a viable option for the treatment of this type of industrial effluents. [ABSTRACT FROM AUTHOR]

Air Conditioning with renewable energy is a key issue in the region's energy policy. The high temperatures usually attributed to climate change and the increase of the standard of living in society continues increasing energy demand in order to establish the conditions for thermal comfort in buildings. Solar air conditioning, although it contains a mature technology, its level of market introduction and acceptance by designers of buildings is exhaustive. This paper discusses the feasibility of these projects, identifies non-technological type barriers that hinders such use and implementation of solar energy for air conditioning systems, and finally, it approaches some criteria and recommendations to overcome these obstacles. [ABSTRACT FROM AUTHOR]