Removal of methylene blue from aqueous solution by adsorption onto the sand titaniferous [Elimination du bleu de méthylène dans l'eau par adsorption sur le sable titanifère]

Two types of titaniferous sand (ts) of taghazout (agadir region) were prepared,using the sieving as a method of separation of grain sizes; st(100-315μm) and st(80-100 μm),for testing their adsorption capacity of methylene blue,from aqueous solution onto the sand (ts),0.13mg/g and 0.24mg/g respectively,at the operating conditions,25 ml of the methylene blue solution of initial concentration 10 mg/l within 30 min. the amount adsorbed optimal for both type of sand is observed in the vicinity of (phzero),it can be interpreted that the diffusive interactions are those that promote the adsorption process. dubinin isotherm and the pseudo-second-order were found to be the best model to describe the adsorption process. the thermodynamic studies revealed that a greater adsorption can be obtained at higher temperatures and the process was found to be endothermic physisorption. accordingly,the sand (ts) was shown to be a very efficient and low cost adsorbent to remove the dyes from aqueous solutions,using a granulometric processing.