Adsorption of methylene blue from aqueous solution onto perlite

Adsorption of methylene blue from aqueous solutions onto unexpanded and expanded perlite samples activated by H2SO4 and NaCl solutions has been investigated, to assess the possibility of using perlite for removing cationic dyes from aqueous solutions. The effects of pH and temperature of dye solution on the adsorption capacities have been evaluated. The experimental data were correlated reasonably well by the Langmuir adsorption isotherm and the isotherm parameters (Q(m) and K) have been calculated. The removal efficiency (P) and dimensionless separation factor (R) have shown that perlite can be used for removal of methylene blue from aqueous solutions, but unexpanded perlite is more effective.