Remediation of remazol dyes by biochar derived from Caulerpa scalpelliformis-An eco-friendly approach

In this research, biochar prepared from green marine algae (Caulerpa scalpelliformis) was used as a sorbent for the remediation of four different remazol dyes. The adsorption studies indicated that maximum removal efficiency of 81% was achieved at the optimum equilibrium pH of 2, Biochar dosage of 2 g/L, initial concentration of 0.05 mmol/L and temperature of 30 degrees C. In this work, different isotherm models like Sips, Toth, Freundlich and Langmuir were also employed to find the best fit model for the experimental data. Based on % error values and correlation coefficients, Toth model (R-2 = 0.99 and % error = 0.60) performed well to describe the sorption isotherms in comparison with other models. The thermodynamic studies revealed that all the reactions are spontaneous and endothermic in nature. Finally, the elution experiments were carried out with different elutants and NaOH was found to be the best elutant for desorption of biochar.