Sorption Properties of Organo Modified Montmorillonite Clay for the Reclamation of Chromium (VI) from Waste Water

The natural Montmorillonite (Mt) clay was modified with three newly synthesized cationic surfactants such as 2-(dodecanoyloxy)-N,Nbis(2-hydroxyethyl)-N(oxiran-2-ylmethyl) ethane-1-ammonium chloride, 2-hydroxy- N- (2-hydroxyethyl) - N (oxiran-2-ylmethyl)-N-(2-(tetradecanoyloxy) ethyl) ethane-1-ammonium chloride and 2-hydroxy-N(2- ydroxyethyl)- N-(oxiran-2-ylmethyl)-N-palmitoyloxy) ethyl) ethane-1-ammonium chloride to get organo OMt- I, OMtII and OMt- III respectively. The three modified clays were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Thermo gravimetric Analysis (TGA), X - Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) techniques. The three modified OMts were utilized to reclaim Cr (VI) from wastewater and batch adsorption studies were conducted with various operational parameters such as initial Cr (VI) concentration, pH, amount of adsorbent dosage and agitation rate. The effect of pH on the adsorption of Cr (VI) indicates that the adsorption was favorable in the pH range of 6. As the amount of adsorbent dosage increases, the efficiency in the removal of Cr (VI) ions increases. Langmuir and Freundlich adsorption isotherm best fitted with the experimental isotherm data. The results show that the modified Mt has a good affinity toward the reclamation of Cr (VI) ion and the degree of the efficacy was in the order of the surfactant modified OMt III > OMt II > OMt I. This can be attributed to the increasing hydrophobic chain length of cationic surfactants.