Malachite green dye behaviors in the presence of biosorbents from maize (Zea mays L.), their Fe-Cu nanoparticles composites and Fe-Cu nanoparticles

The sorption behaviors of biosorbent based on maize (Zea mays, ZM) cane (bagasse and stalk), their composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles for malachite green from aqueous solutions were investigated in this work. Adsorbents were characterized using BET, infrared spectroscopy, X-ray diffraction, SEM-EDS, and Fe-Cu nanoparticles were characterized by TEM. The study of the sorption kinetics indicates that the adsorption on malachite green by stalk and their composite follows second-order kinetics and nanoparticles and bagasse and their composite follow the pseudo-second order model. The malachite green adsorption by ZM/Fe-Cu composites were faster than natural materials and only showed two phases in the intraparticle diffusion model, probably due to the minor internal diffusion resistance. The adsorption isotherms experimental data were analyzed by the Langmuir, Freundlich and Langmuir–Freundlich models and the equilibrium data was well described by the Langmuir–Freundlich isotherm model. The adsorption was more favorable at basic pH. The OH-groups were proportional to dye adsorption capacities. Results showed that composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles possessed good adsorption abilities to malachite green.Project 3688/2014/CIB UAE

Properties of carbonaceous materials from sewage sludge to remove organic matter. Phenol as a particular case

Carbonaceous material obtained from the pyrolysis of sewage sludge, activated carbon (AC), a composite CM(Fe-Cu) (carbonaceous material/nanoparticles of Fe-Cu) and nanoparticles N(Fe-Cu) were used to evaluate and compare their abilities to remove phenol from aqueous solutions by adsorption followed by oxidation. The adsorbents were characterized by scanning electron microscopy, transmittance electron microscopy, Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction and Infrared (IR) spectroscopy. The presence of Fe-Cu nanoparticles was confirmed by the TEM technique. Sorption kinetics and isotherms were determined in the presence and absence of hydrogen peroxide. The experimental kinetic data of the activated carbon and the carbonaceous material were treated with Lagergren, Elovich and Ho models. The results show that both materials are best fit to the second order model indicating a chemisorption mechanism. The adsorption equilibrium of phenol by the different adsorption materials was observed in 24 h. The adsorption capacity of CM(Fe-Cu) for phenol was not affected by the pH, and the adsorption capacities for CM and AC decreased as the pH increased. The isotherms were lineal in all cases. N(Fe-Cu) was the most efficient material for the removal of phenol from aqueous solutions. The adsorption capacities decreased as the doses increased and the adsorption capacities of the materials were not affected by the temperature when it was between 30 and 50°C; only the composite CM(Fe-Cu)in the presence of hydrogen peroxide showed an endothermic behavior. The highest adsorption capacities were for N(Fe-Cu) in the presence and absence of hydrogen peroxide

Removal of indigo carmine by a Ni nanoscale oxides/Schoenoplectus acutus composite in batch and fixed bed column systems

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater

Sorción de fenol mediante un composito de Fe-Cu

La remoción de fenol de soluciones acuosas fue evaluada empleando un material carbonoso obtenido de la pirolisis de lodos residuales, composito (material carbonoso/Fe-Cu) y carbón activado comercial a partir de solución acuosa por procesos Fenton en un sistema batch. Cinética de sorción e isotermas se determinaron en presencia y en ausencia de peróxido de hidrógeno y se analizaron los comportamientos de adsorción. Los datos de las cinéticas obtenidos para cada proceso de adsorción mostraron que el material carbonoso modificado (composito) presentó una mayor capacidad de adsorción C(Fe-Cu)PF (qe= 8.60 mg/g) comparada con los demás materiales.Removal of phenol from aqueous solutions was evaluated using a carbonaceous material obtained from the pyrolysis of sewage sludge, composite (carbonaceous material Fe-Cu) and commercial activated carbon from aqueous solution by Fenton processes in a batch system. Sorption kinetics and isotherms were determined in presence and absence of hydrogen peroxide and adsorption behaviors were analyzed. Kinetic data obtained for each adsorption process showed that the modified carbonaceous material (composite) showed higher adsorption capacity C (Fe-Cu) PF (qe= 8.60 mg/g)

Malachite green dye behaviors in the presence of biosorbents from maize (Zea mays L.), their Fe-Cu nanoparticles composites and Fe-Cu nanoparticles

The sorption behaviors of biosorbent based on maize (Zea mays, ZM) cane (bagasse and stalk), their composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles for malachite green from aqueous solutions were investigated in this work. Adsorbents were characterized using BET, infrared spectroscopy, X-ray diffraction, SEM-EDS, and Fe-Cu nanoparticles were characterized by TEM. The study of the sorption kinetics indicates that the adsorption on malachite green by stalk and their composite follows second-order kinetics and nanoparticles and bagasse and their composite follow the pseudo-second order model. The malachite green adsorption by ZM/Fe-Cu composites were faster than natural materials and only showed two phases in the intraparticle diffusion model, probably due to the minor internal diffusion resistance. The adsorption isotherms experimental data were analyzed by the Langmuir, Freundlich and Langmuir–Freundlich models and the equilibrium data was well described by the Langmuir–Freundlich isotherm model. The adsorption was more favorable at basic pH. The OH-groups were proportional to dye adsorption capacities. Results showed that composites (ZM/Fe-Cu nanoparticles) and Fe-Cu nanoparticles possessed good adsorption abilities to malachite green.Project 3688/2014/CIB UAE

Tartrazine removal by ZnO nanoparticles and a zeolite-ZnO nanoparticles composite and the phytotoxicity of ZnO nanoparticles

ZnO nanoparticles (nanZnO) and a zeolite-ZnO nanoparticles composite (Ze-nanZnO) were prepared and characterized. These materials were used for the removal of tartrazine from aqueous solutions by an adsorption-photocatalysis coupled process. The adsorption using nanZnO showed a rapid decrease of the concentration of tartrazine and the adsorption by using the composite Ze-nanZnO was slower. The degradation of tartrazine by using both materials in the presence of ultraviolet light seems to be a highly efficient process for both materials, 87 and 81% degradation were observed for nanZnO and Ze-nanZnO respectively, although the first material seems to be more efficient than the second, this first material is difficult to remove from the aqueous solution after the process. The mineralization was monitored by measuring the total organic carbon at different contact and irradiations times. The degradation of the dye was high between 85 and 90%, higher degradation was observed using Ze-nanZnO as catalyst than nanZnO. “Lactuca sativa” species suffer “low toxicity” when they are in contact with solutions containing the dye and solutions that were in contact with nanZnO

Removal of indigo carmine by a Ni nanoscale oxides/Schoenoplectus acutus composite in batch and fixed bed column systems

Removal behavior of indigo carmine by Schoenoplectus acutus and Ni nanoscale oxides/Schoenoplectus acutus composite was determined. The characterization of both materials was done by TEM, SEM/EDS, DRX, and BET. Experimental data were best fitted to pseudo second order and Langmuir-Freundlich models for kinetics and isotherm, respectively; these results indicate a chemisorption mechanism on heterogeneous materials. Adsorption capacity of Ni nanoscale oxides/Schoenoplectus acutus composite was high in comparison with other adsorbents (760 mg/g). Adsorption of dye is not affected by pH (3 to 9). Metal nanoparticles supported on cheap and eco-friendly adsorbents are an alternative for the removal of dyes from wastewater

Desarrollo de un sistema para el monitoreo en tiempo real de contaminantes atmosféricos en la vertical de la Zona Metropolitana del Valle de Toluca, México.

En años recientes se ha presentado un gran interés en el monitoreo de los contaminantes atmosféricos y parámetros meteorológicos en la vertical y en tiempo real. El desarrollo de la tecnología ha abierto la posibilidad de utilizar vehículos aéreos no tripulados (UAV) como plataforma para el monitoreo del aire y disminuyendo costos de operación. Debido a la capacidad de carga de los UAV, es necesario desarrollar sistemas de monitoreo ligeros. El objetivo de esta investigación fue desarrollar e integrar un sistema ligero de no más de 1200 g de peso, provisto de diferentes sensores de contaminantes atmosféricos y de parámetros meteorológicos para ser transportado en un UAV, que incluya comunicación remota y realizar monitoreos de contaminantes atmosféricos en vertical de diferentes sitios de la Zona Metropolitana del Valle de Toluca, ZMVT. Para cumplir con el objetivo se desarrolló la siguiente metodología: Se realizó la búsqueda de sensores electroquímicos con menor interferencia entre gases, vida útil relativamente larga, rango de medición de concentraciones amplia, valor mínimo detectable bajo y costo accesible. Se realizaron pruebas del montaje optimo de la caja de sensores en el UAV, así como el desarrollo del sistema de anclaje y estabilización del sistema de monitoreo. Los resultados obtenidos fueron la integración de un sistema con sensores electroquímicos para medir CO2, CO, NO2, NO, SO2 y O3, sensor óptico para medir el material particulado, sensores de velocidad del viento, temperatura, humedad relativa y radiación solar, GPS y radio de comunicación; así como bombas que suministran la muestra de aire a los sensores y un contenedor para retener partículas para su posterior análisis. El suministro de energía se realiza con baterías permitiendo el monitoreo continuo por 3 h. Se logró un peso total de 1100 g. Se probó con éxito el funcionamiento del sistema realizando mediciones de las concentraciones de contaminantes atmosféricos en la vertical a 120 m de altura, se presentaran los resultados de los primeros muestreos con el sistema de monitoreo.  Por ejemplo, el sensor de Ozono que se comparó contra un medidor de ozono T 400 tiene una variación de 2.1 % a 400 ppb