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Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ingeniería y Competitividad is the property of Universidad del Valle and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A predictive molecular adsorption model for organic compounds over TiO2-P25 particles was formulated. The model is an extension of a theoretical method of surface characterization called Protonic Distribution Affinity (PDA), which is obtained from potentiometric titration analysis, zero point charge (ZPC) of the material and adsorption isotherms of the Langmuir-Hinshelwood type. The chemical nature of the compound in the model was established by initial pH and molecular weigh. We found that, for the TiO2,-P25, the ZPC was 6.8. The model was validated using experimental data of dichloroacetic acid (DCA), 4-chlorophenol (4-CP) andphenol (PH) to different conditions. The model has high predictive capacity, numerical stability and sturdiness for obtaining the solutions. For available experimental data, the correlation coefficient was 0.97. [ABSTRACT FROM AUTHOR]

Vinasse is the most important waste from the bioethanol plants due to its high polluting potential, forthis it has received special attention because of interest to develop new treatment alternatives. It was evaluated the remo val capacity of solids content and other parameters of vinasse by using electro-dissolution of iron and chemical flocculation through separate stages. The appropriate operating conditions for electro-dissolution were established by means of linear polarization sweeps and electrochemical impedance spectroscopy analyses. During the flocculation were conducted jar tests by using Ca(OH)2 as coadjuvant agent and as pH modifier. In this way, was possible to diminish 84% total solids, 54% chemical oxygen demand, 88% dissolved organic carbon and 76% color. The electrical consumption during electro-dissolution was 0.25 kWh/m³. [ABSTRACT FROM AUTHOR]

Solar heterogeneous photocatalysis is an advanced oxidation technology, which allows a successful treatment of many recalcitrant and emergent pollutants, such as: pesticides, industrial dyes and pharmaceutical compounds. Nonetheless, despite its effectiveness, the costs of applying this process are high when it is necessary to achieve a complete mineralization or to obtain an environment-friendly effluent. Photocatalytic-biological coupled systems have become in a feasible alternative able to treat efficiently these pollutants. In this work, a coupled system consistent of two compound parabolic collectors (CPC) solar photoreactors and a subsurface flow constructed wetland (SFCW) at pilot-scale was tested for degrading a mixture of commercial pesticides used in sugar cane crops. For measuring the process performance, regarding to the pollutant removal, the increase of the BOD5/COD ratio and the total organic carbon (TOC) removal were estimated for each separated system and the coupled system. Three different levels of solar UV accumulated energy and feed flow-rates to the SFCW were considered for the experimental design. The pilot-scale coupled system increased the BOD5/COD ratio from 0.15 to 0.90, and the TOC removal (total mineralization) was around 80%. [ABSTRACT FROM AUTHOR]

This work reports the results obtained from the transesterification of castor oil with methanol under soft conditions (low temperature and atmospheric pressure), employing basic solids as Ba/ZnO, Mg/ZnO, and K/ZnO. It was found that the different systems exhibit high catalytic activity for the transformation of castor oil, but the Ba/ZnO system showed a highest tendency toward cyclation of ricinoleic acid to form a product known as macrolactone, namelly (E)-13-n-hexyloxacyclictridec-10-en-2-ona. The catalytic systems were analyzed through FT-IR, TEM, SEM, X-ray diffraction, temperature programmed reduction, analysis of surface area and the esters obtained from the reaction were analyzed by gas chromatography coupled to mass spectroscopy (GC-MS). [ABSTRACT FROM AUTHOR]

This study assessed the effect of the geometry and concentration of substrate in the determination of overall quantum yields. The quantum yields were obtained under an approach of constant global parameters based on the properties of isotropic radiant field and perfect distribution of particles in the fluid phase. An idealized model for quantifying the radiation field was used for reaction rate and overall volumetric rate of photon absorption (OVRPA) were obtained by means of an approximate solution of the radiative transfer equation (RTE). The results for quantum yields allowed to show the non-intrinsic nature of the kinetics parameters because of the strong influence of geometry associated to the dependence on the radiant energy absorbed by the system, evaluating these photo-kinetic parameters at constant initial concentration of dichloroacetic acid (DCA). The overall relative error between the simulation and experimental data is less than 2.5% and the correlation coefficients are greater than 0.97. [ABSTRACT FROM AUTHOR]