ETUDE DE LA BIOSORPTION DE COLORANTS PAR DIVERS MATERIAUX

Abstract

Many industries, such as plastics, and textile use dyes to color their products and also consome substantial volumes of water .Due to their good solubility, synthetic dyes are common water pollutants and they may frequently be found in industrial waste water. The presence of very small amounts of dyes in water is highly visible and undesirable. Due to increasingly stringent restrictions on pollutant content of industrial effluents, it is necessary to remove dyes from waste water before it is discharged into environment .

Adsorption techniques are proved to be an effective and attractive process for removal of non biodegradable Pollutants from wastewater . Most commercial systems use activated carbon as adsorbent to remove dyes in wastewater because it has excellent adsorption ability. But it is widespread use is limited due to high running cost. Many low cost adsorbents, including natural materials, biosorbents, and waste materials from industry and agriculture have been proposed by several workers.

The biosorption of a cationic and anionic dye, methylene blue and yellow supranol from aqueous solution onto plum tree and artichoke leaf powder was investigated at different temperature. Equilibrium data were analyzed using Freundlich , Langmuir equations. All of the isotherm parameters were calculated. The Langmuir model gave a better conformity than Freundlich equation.The adsorption was favorable at higher pH for methylene blue and lower for yellow supranol. In order to clarify the sorption kinetic, the fit of pseudo-first-order kinetic model , second –order kinetic model and intraparticule diffusion model were investigated. It was obtained that the biosorption process followed the pseudo-second –order rate kinetic. Thermodynamic parameters suggest that the adsorption is a typical physical process , spontaneous, exothermic and endothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue and yellow supranol from aqueous solution.