Removal of Color Pollutant from Wastewater Using Phragmites Australis and Sawdust as Biosorbents

Abstract

     In this study, powders of Phragmites australis (Phm) and Sawdust (SD) were utilized as biosorbents to remove Rhodamine 6G (R6G) as a cationic dye from wastewater. The surface characteristics of these biosorbents were examined using atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FT-IR) before the adsorption experiments. The batch adsorption method was employed to investigate the influence of various factors, including the amount of Phm and SD powder, adsorption period, initial concentration of adsorbate, temperature, and pH that affected on the adsorption process. The results showed that the highest removal efficiency (R%)for R6G dye was found at an adsorbent weight of 0.16g, a concentration of 10 mg/L, an adsorption time of 30 min, and a pH of 7 for both SD and Phm. Adsorption isotherms at different temperatures were observed following L-type, and through the adsorption isotherm models used, it was found that the adsorption of R6G dye is better described by the Freundlich isotherm (FrI) model. Thermodynamic parameters analysis suggests that the adsorption process is endothermic in nature, spontaneous, and occurs with an increase in disorder for SD as adsorbent, while for Phm it is an exothermic process that occurs with a decrease in disorder. In addition, the adsorption of R6G dye onto both Phm and SD is of a physical adsorption type. The kinetic data were analyzed by pseudo 1^st and pseudo 2^nd models, and were found to follow a pseudo 2^nd model with correlation coefficients (R² >0.9987and 0.9996) for Phm and SD, respectively. The study revealed that both SD and Phm represent potential low-cost biosorbents that effectively remove R6G dye from aqueous solutions.