A comparative study on the adsorption of two remazol dyes on green adsorbent

Abstract

Due to the large amount of wastewater discharged by the textile industry, many alternative researches have been undertaken in recent years to effectively remove textile dyes from water. In our study, the adsorption from aqueous solution of two important textile dyes, reactive azo dyes Remazol Red (RR) and Remazol Blue (RB) was studied with calcined chicken eggshell (Gallus Gallus domesticus) adsorbent. Batch biosorption studies were conducted to evaluate the effect of various parameters, such as contact time, initial dye concentration, amount of adsorbent, and pH, to determine the optimal adsorption parameters (Remazol Brilliant Red F3B: Ci=20 mg/l, 1.5g adsorbent, 160 μm, 700 rpm, pH=6.0±0.2, T=20±2 oC, where E%=97.3; Remazol Brilliant Blue R: Ci=20 mg/l, 1.5 g adsorbent, 160 μm, 700 rpm, pH=6.0±0.2, T=20±2oC, where E%=98.8). The changes in morphological structure were evaluated by SEM analysis. The experimental isotherm data were analyzed using the Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models. Biosorption kinetics data were tested using pseudo-first-order, pseudo-second-order, where in our experimental conditions the biosorption followed a pseudo-second-order reaction. EDS analyses were carried out, and bioconcentration factors were calculated before and after adsorption. The results of this study indicate that adsorption with calcined eggshell is a promising, feasible, reliable and ecofriendly method for Remazol textile dye removal from aqueous solutions.