Decolorization of basic textile dyes using a novel adsorbent modification method: ultrasonic-acid modification

Abstract

In this study, removal of methylene blue (MB) and maxilon blue SL 200% (MB SL) dyes from aqueous solutions by using raw clay (RC) of Nevsehir (Turkey) vicinity and ultrasonic-acid modified clay (MC) was investigated. Adsorption was carried out with 500 mg/L MB and 50 mg/L for MB SL in terms of different adsorbent dosages, contact time, solution pH, temperature and stirring speed. The fitting of adsorption process with respect to Freundlich and Langmuir isotherms was examined. In this study, it was determined that the experimental data for MB dye removal by using RC (R2= 0.9737, Qo=3333 mg/g) and MC (R2=0.9914, Qo=5000 mg/g) were well fitted to Langmuir isotherm model. In addition to this, the experimental data for the removal of MB SL dye by using RC (R2= 0.9104, KF =19.45 mg/g) and MC (R2=0.9933, KF =44.62 mg/g) were well fitted to Freundlich isotherm model. As a result; it was indicated that raw clay can be used for the removal of cationic MB and MB SL dyes and ultrasonic-acid modified clay has high adsorption capacity for both of the dyes. Low-cost clay can be used for the removal of MB and MB SL dyes in preference to other adsorbents. Ultrasonic-acid modification was found as an alternative significant method for adsorbent modification.