Eco-friendly Biosorption Process of Reactive Blue 52 Dye Using Alga Dried Biosorbent of Filamentous Alga Species: Equilibrium, Kinetic Studies and Intervening Effect

Abstract

Background & objectives : Dyes are structurally complex materials, which enter into the environment due to discharging of textiles effluent from dyeing and printing processes. Reactive Blue 52 dye is used widely in the textile industry. Therefore, we investigated the efficiency of the filamentous Alga as natural adsorbent in the removal of Reactive Blue 52 dye from textile wastewater. Methods: This experimental study was performed in laboratory scale. In this study, the effect of adsorbent dose, contact time, pH and different dye concentrations on efficiency of adsorption process were studied and finally, fitting rate of data for Langmuir and Freundlich isotherms and also pseudo-first-order and pseudo-second-order adsorption kinetics were determined. For analysis of the data, linear regression and R-squared were used. Results: According to the obtained results, increasing of adsorbent dose to 22 g/100 mL in concentrations of 50 mg/L RB52 led to an increase of removal efficiency to 58.04%. Adsorption capacity was increased from 31.2 to 8.41 %, by increasing the initial pH from 3 to 11 for concentrations of 10 and 25 mg/L, respectively. Results showed that with the increase of contact time, removal efficiency increased and with increasing of initial dye concentration, the removal efficiency decreased. Langmuir isotherm was in good concordance with the data. The model of pseudo-second-order kinetic demonstrated better fitting with the experimental data. Conclusion: The results indicated the suitability of filamentous Alga as natural adsorbent for color removal.