Application of low-cost material for adsorption of dye from aqueous solution

Abstract

Cationic dyes are one of the aromatic compounds that cause major environmental problems. The adsorption process has attracted a lot of attention in recent years. In this study, the seeds were used as a low-cost adsorbent for the removal of cationic Blue 41 dye from aquatic environments. The studied parameters included the effect of adsorbent dosage, pH of the solution, contact time, and the initial concentration of Cationic Blue 41 dye. The removal efficiency in optimal conditions for Cationic Blue 41 with Salvia seeds (concentration = 50 mg/L, dose = 2 g/L, reaction time = 120 min and pH = 9) was obtained 70%. The data were evaluated using Freundlich and Langmuir methods. The structure and characteristics of the seeds were determined by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Brunauer-Emmett-Teller (BET) techniques. The SBET and total pure volume for the Salvia seeds were 3.053 m2/g and 0.684 cm3/g. The results showed that the adsorption process follows Langmuir model with an adsorption capacity of 19.16 mg/g. According to the result of the pseudo-first and pseudo-second kinetic study, it was found that the process of dye adsorption on the low-cost seeds best described by pseudo-second kinetic. The findings showed that the Salvia seeds can be used as a natural absorbent, environmentally friendly and affordable treatment for water and wastewater, especially those containing cationic dyes.