Alternative low-cost adsorbent for water and wastewater decontamination derived from eggshellwaste: an overview

As the current global trend towards more stringent environmental standards, technical applicability and cost-effectiveness became key factors in the selection of adsorbents for water and wastewater treatment. Recently, various low-cost adsorbents derived from agricultural waste, industrial by-products or natural materials, have been intensively investigated. In this respect, the eggshells from egg-breaking operations constitute significant waste disposal problems for the food industry, so the development of value-added by-products from this waste is to be welcomed. The egg processing industry is very competitive, with low profit margins due to global competition and cheap imports. Additionally, the costs associated with the egg shell disposal (mainly on landfill sites) are significant, and expected to continue increasing as landfill taxes increase. The aim of the present review is to provide an overview on the development of low-cost adsorbents derived from eggshell by-products

Understanding RuO2·xH2O/carbon nanofibre composites as supercapacitor electrodes

Composites made from RuO2·xH2O particles supported on carbon nanofibres (CNF) have been prepared for supercapacitor electrodes. CNF, produced by Grupo Antolin Ing. SA. using a floating catalyst procedure was treated either in HCl or in HNO3. Then the composites were obtained by impregnation of CNF with an aqueous RuCl3·0.5H2O solution followed by filtering and alkali solution treatment. Heat treatment at 150 ◦C for 2 h was done. Specific capacitance of the composites has been measured and discussed on the basis of their RuO2·xH2O content and RuO2·xH2O particle size. The composites having RuO2·xH2O contents below 11 wt% show RuO2·xH2O particles, which grow from 2 to 4 nm as the RuO2·xH2O content increases. The specific capacitance of supported RuO2·xH2O, which can be very high (up to 840 F g−1), decreases as the RuO2·xH2Ocontent increases and RuO2·xH2O particles grow. The composites having RuO2·xH2O contents above 11 wt% show RuO2·xH2O particles of nearly constant size (4 nm); the effect of increasing the RuO2·xH2O content is to increase the amount of particles but not the size of the particles. In these composites the specific capacitance of supported RuO2·xH2O is nearly constant (440 F g−1) and close to bare RuO2·xH2O (460 F g−1).Financial support trough the project of reference MAT 2005- 01606 is gratefully acknowledged. F. Pico thanks for a contract associated with that project. We thank C. Merino, P. Soto and F. Martinez from Grupo Antolin Ing. SA., for providing carbon nanofibres.We thank Mr. Adrian Gomez for technical TEM support.Peer reviewe

Amorphous Carbon Nanofibers and Their Activated Carbon Nanofibers as Supercapacitor Electrodes

Carbon nanofibers (CNFs) show a high electrical conductivity but a reduced specific surface area that limits their use as electrode materials for supercapacitors. In this work, amorphous CNFs, with a relatively high electrical conductivity are easily activated in KOH, using certain KOH/CNF weight ratios. Activation does not produce any important change in the shape, surface roughness, diameter, graphene sheet size, and electrical conductivity of starting nanofibers. However, activation leads to new micropores and larger surface areas as well as a higher content of basic oxygen groups. They clearly enhanced the specific capacitance, attaining values higher than those reported for other activated CNFs. In this study, the effects of micropore size and oxygen content on the specific capacitance are discussed for three electrolytes: H2SO4, KOH, and (CH3CH2)4NBF4. Moreover, a good cycle life is found for the most activated CNFs.Acknowledgment. Financial support through the project of reference MAT 2008-03182 is gratefully acknowledged. V.B. thanks the Spanish Ministry of Science and Innovation for a RyC contract. F.P. thanks CSIC for a JAE doc contractPeer reviewe

Adaptación de asignaturas del Máster en Ciencia de Materiales a la modalidad de enseñanza semi-presencial

El proyecto de esta red titulado “Adaptación de asignaturas del máster en Ciencia de Materiales a la modalidad semipresencial” ha pretendido iniciar la reflexión sobre la posibilidad de reducir la presencialidad en la docencia del máster en Ciencia de Materiales, con la finalidad de facilitar que los alumnos puedan compaginar mejor los estudios de este máster con otras actividades. En un primer paso, se ha planteado planificar la docencia de tres asignaturas del máster (una del módulo fundamental y dos optativas) en forma semipresencial. De este modo, si esta nueva metodología es bien aceptada, podría plantearse su extensión al resto de asignaturas. Las asignaturas seleccionadas para este estudio son: “Técnicas de caracterización I: Dispersión de rayos X, neutrones y electrones. Microscopias”; “Materiales compuestos”; e “Introducción a la ciencia y tecnología de los materiales de carbón”. La adaptación de los métodos didácticos de estas asignaturas a la docencia semipresencial implica la preparación y selección de una serie de materiales adicionales a los que se han usado habitualmente. Con el fin de valorar el interés de los alumnos por esta posible modificación de la metodología de docencia en el Máster en Ciencia de Materiales, en el curso actual se realizó una encuesta a los alumnos del mismo. Los resultados de ésta indican que la incorporación de la docencia semipresencial sería una iniciativa bien recibida por el alumnado