Polymer Chemistry

The discharges from many industries (plastics, cosmetics, paper, and particularly textiles) are heavily loaded with dyes which have dangerous toxicological impacts on the environment.

           Methyl orange is an anionic azo dye widely used in laboratories and in the textile industry. Carcinogenic and mutagenic, it is a powerful water pollutant. And also Safranin is one of the most widely used synthetic azo cationic dyes. It comes as a reddish brown water soluble powder, which is mainly used as a food coloring in flavoring candies and cookies. Safranin is also used to dye tannin, cotton, bast fibers, wool, silk, leather and paper.

        The aim of this work is the liquid-solid extraction of cationic or anionic dyes from dilute aqueous solutions of 10 mg / l of the two dyes by a material based on the zeolite. The effect of several parameters on adsorption performance were studied (contact time, mass of the support, pH, etc.).

The results obtained are as follows:

• The adsorption equilibrium was obtained after 180 min of two cationic dyes (SF and BM) with a low mass of zeolite (0.1g) and at pH = 6.5.

• The adsorption capacity of the dye by the zeolite increases slightly with increasing temperature from 25 ° to 55 ° C.

• The evolution of the adsorption capacity over time at different concentrations of the dye ranging from 10 to 200 mg / l with a maximum absorption capacity of the dye by the zeolite at such that.

 Qmax (SF) =

 Qmax (BM) =

          The study of kinetic models confirm, on the one hand, that the adsorption of the two dyes (SF) and (BM) on the zeolite follows the pseudo-first order model, and on the other hand, that the Langmuir isotherm is the appropriate model to explain the adsorption process of safranin on zeolite.