Recycling the wasted bentonite clay as a low-cost and novel adsorbent for the removal of the methylene blue dye in the aqueous solution

Abstract

This study aims to recycle thermal remediated bentonite clay waste (TRBCW) as a green, new, low-cost adsorbent to remove the methylene blue (MB) dye in an aqueous solution. The first system was the batch adsorption experiments having five condition parameters: contact time, pH, temperature, initial concentration of MB, and dose of TRBCW adsorbent. From the analysis of the batch adsorption data, it was apparent that the adsorbing of MB molecules on the TRBCW adsorbent was endothermic, irreversible, promising, spontaneous, and favorable. The Fruendlich model was more compatible than the Langmuir model for the experimental batch adsorption data, and the maximum adsorption capacity was 34.77 mg/g. The second system is the continuous (fixed-bed column) having three investigated condition parameters: the influent MB concentration, flow rate, and (TRBCW weight) bed depth, the adsorption capacity that results from the dominant parameters (1ml/min, 50 mg/L, and 22 cm) was 61.37 mg/g, and the experimental continuous adsorption data were more suitable with Yoon-Nelson, Thomas, and BDST models with R2> 0.9.

Keywords

• adsorption
• bentonite clay waste
• batch system
• methylene blue dye