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This study involves the adsorption of Crystal Violet (CV) dye adsorbed from solution on the pyrophyllite's surface. The batch technique was used under a variety of conditions to produce quantitative adsorption, namely amount of adsorbent, dye concentration, contact time, pH solution and temperature. The maximum adsorption capacity of Crystal Violet on pyrophyllite was 9.58 mg/g for 10 mg/L of CV concentration, pH = 6.8 at a temperature 20°C and 1 g/L of adsorbent. This study of adsorption kinetics was carried out within framework of three models: intraparticle diffusion, pseudo-first order and pseudo-second order. The experimental isotherm data were analyzed using Langmuir and Freundlich models. Different thermodynamic parameters have shown spontaneous reaction with endothermic nature (The estimated value for DG was À7.64 kJ/mol at 293 K). Various techniques for characterizing the adsorbent were applied including X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) coupled by energy dispersive X-ray spectroscopy (EDX). In addition, the regenerated adsorbents technique was reused several times; this demonstrated an economical aspect of using pyrophyllite which underlines the re-use importance considering the material capacity to regenerate.

A new tool--the Membrane Fouling Simulator (MFS)--is developed to measure membrane fouling (pressure drop increase) in a small and simple system, representative for spiral wound membranes applied in water treatment. With the MFS, fouling development can be monitored systematically by (i) pressure drop, (ii) in situ and non-destructive (visual) observations using the sight glass and (iii) analysis of coupons sampled from the membrane sheet in the MFS. A comparison study of the MFS with spiral wound membrane elements (test rigs and a full scale installation) showed the same fouling. The MFS provided reproducible data. The small size and low water and chemical use of the MFS facilitate to perform systematic parallel studies. With the MFS, fouling of membranes applied in water treatment can be characterised.

In the course of this project we were able to develop a wastewater treatment method, column filtration, which turned out to be effective, affordable, and easily implementable. We tested filtration/adsorption process on a mixture of three dyes, methylene blue (MB), crystal violet (CV), and methyl orange (MO) on a column 50 cm of height and 5 cm in diameter. The column material consisted of equal amounts of walnut shells powder (WSP), corn cob powder calcined (CCPC), and pyrophyllite (PY) was proved to be more efficient. The aim of the present study was to optimize and standardize the operational and experimental parameters of the column. A number of tests were carried out to do this by changing the particle size of the adsorbent materials, the percolation debit of the filtrate and the height of the filter bed. The examination by UV-visible spectrometry shows that the removal percentage by 99% was carried out by the diameter of 120 lm predominantly with percolation debit of the filtrate of 50 mL min À1 and the height of column bed of 4.5 cm. When the materials having macroscopic porous structure with a very small grain diameter were used, of small-sized dyes into the filtering medium without being trapped. On the other hand, it is noticed that the efficiency of the adsorption by filtration increases with the increase in the height of the filter bed and decreases with the increase of both the percolation debit and particle size of the adsorbents.

This article presents two aspects environnementals: valorization of oil shale ash (OSA) of oil industry on the one hand, and on the other hand to study the effectiveness of cation adsorption of dye such as the Methylene blue (BM) on material (OSA).In this context, we carried out a parametric study of adsorption, in particular, the time of contact, the pH, the amount of the adsorbent, the temperature and the stirring velocity. A study of the kinetics of adsorption was carried out by two models: pseudo-first order and pseudo-second order, and a modeling by the isotherms of adsorption while basing itself on the models of Langmuir and Frendlich. The maximum capacity of adsorption of BM on OSA is of 2,464 mg/g, for a concentration of BM of 5 mg/L, an amount of adsorbent of 2 g/L. Material OSA was characterized by several methods such as diffraction of x-ray (DRX), electronic scan microscopy (MEB), electronic microscopy in transmission (MET), x-ray fluorescence (FX), and the infra-red Spectroscopy with transforms of Fourier (FTIR). In addition, the economic aspect of the use of OSA makes important the re-use of these materials considering their capacity to regenerate itself.