Numerical Ways to Characterize the Deterioration of Nanofiltration Membranes

In this study, a transport model is used to characterize structural and physico-chemical changes in a nanofiltration membrane during the filtration of ionic mixtures. The membrane state is analyzed by a set of four model parameters identified from glucose and salts filtration: the membrane water permeability (Lp), the mean pore radius (rp), the membrane charge density (Xd), and the dielectric constant of the solution inside pores (ep). The study of these structural and physico-chemical properties allows us to determine if deterioration or fouling occurred during filtration. Two distinct identification procedures from filtration of synthetic solutions are investigated in this paper. One is based on the filtration of single salt solutions, whereas the other lies in parameters identification from mixtures containing at least three ions. These methods are applied here to characterize influence of fouling deposit formation and membrane cleaning

Facile Elaboration of Wet Cellulose Film as Catalyst Support of MnOx Nanoparticles for the Catalytic Oxidation of Dyes in Absence of Light

In the present work a remarkably simple procedure for the elaboration of wet cellulose film containing manganese oxide nanoparticles was developed. The films were produced using a mold made by 3D printing using cellulose dissolved in an ionic liquid, which allows the production of thin and homogeneous films of different shapes, types and designs which cannot be made using conventional techniques. Thanks to this possibility, the final catalytic object can be implemented in specific reactors. Manganese oxide nanoparticles were prepared as a colloidal solution by a redox/sol-gel procedure and then deposited on the cellulose films by wet impregnation. The catalytic film obtained was tested in the decomposition of a dye, indigo carmine (IC), in the absence of light. The influence of the pH of the solution on the decomposition rate was investigated. IC total decomposition was measured after 1-h reaction at pH below 3. At pH = 2, no deactivation of the catalyst was observed even after four decomposition cycles. This work provides a new strategy to design cellulose-based catalysts for dye removal from wastewater

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage

Physico-chemical properties and thermal degradation characteristics of agropellets from olive mill by-products/sawdust blends

International audienceThis study aims to produce agropellets composed by olive waste, an olive mills by-product, blended with pine sawdust for 6 different mass fraction compositions. Thermal and physicochemical properties of these pellets such as moisture, ash content, bulk density and heating values were determined. In addition, thermogravimetric analyses were performed under inert and oxidative atmosphere in order to assess the thermal degradation behaviour of the produced agropellets. Results show that during the pelletization process, the high value of moisture in olive waste decreases. Values of ash content for each considered sample remain in the accepted agropellets French standards. Thermogravimetric analysis shows that the thermal degradation of the different pellets follows the usual behaviour of lignocellulosic materials. Furthermore, a quite continuous zone corresponding to the not readily char combustible part is detected during TGA under oxidative condition. However, a higher reactivity for PS/OW pellets is observed compared to those reported in literature. Such results prove that olive waste agropellets may be an alternative fuel for producing energy in domestic boilers. (C) 2014 Elsevier B.V. All rights reserved

Influence of operating conditions upon NO2- reduction by Zn in batch reactor: determination of kinetical parameters

International audienc

Transport of salt mixtures through nanofiltration membranes: identification of electric and dielectric contributions

International audienc