Removal of methylthioninium chloride dye from aqueous solution using cogon grass as adsorbent

Abstract

The aim of this study was to investigate the removal Methylthioninium Chloride dye using cogon grass to treat the effluent. The effects of various parameters such as adsorbent dosage, dye concentration and contact time were studied. Funtional group properties of cogon grass had been characterized using Fourier transform infrared spectroscopy (FTIR). The adsorption process attained equilibrium around 50 minutes. The maximum adsorption capacity was calculated to be 46.30 mg/g with optimized condition of adsorbent dosage 0.1 g at temperature 30 °C for 50 minutes. The adsorption kinetics of Methylthioninium Chloride with cogon grass suit into non-linear pseudo-second order reaction model that refers to the amount of adsorbate and amount of solute adsorbed on adsorbent surface at equilibrium. It was also found that the Langmuir isotherm fit better (R 2 = 0.9959) compare to the Freundlich isotherm (R 2 = 0.4093). The high levels of color removals were achieved with low contact times; and the cogon grass can be effectively used as adsorbent of methylthioninium chloride in aqueous solutions. These results prove that cogon grass is highly potential to be used as low-cost adsorbent for the dye removal from industrial wastewater.