Efficiency of Pistachio Tree Sawdust in Removing Reactive Red 11 from Contaminated Aquatic Environment

Introduction: Dyes are among the hazardous pollutants that are often found in fabric wastewater. These pollutants have a significant environmental detrimental effect on the ecosystem of aquatic plants and animals. They are also likely to alter the physical and chemical properties of water. Therefore, in present study, it was attempted to investigate the effect of pistachio tree sawdust on removing reactive red 11 (RR-11). Materials and methods: The present study was conducted experimentally and on a laboratory scale. The impact of effective parameters such as initial dye concentration RR-11 (20-100 mg/L), pH of the solution (4-11), adsorbent amount (0.1- 0.6 g/L) and reaction time (5-100 min) were investigated in RR-11 dye removal efficiency using pistachio sawdust. Finally, isotherms and adsorption kinetics were examined and analyzed as well. Results: The results have indicated that under optimal conditions including initial dye concentration of 40 mg/l, the solution of the pH being equal to 4, pistachio sawdust content of 0.6 g/l, and reaction time of 60 minutes, a removal efficiency of 99.2% is obtained. The adsorption process using sawdust showed a better agreement with second-order kinetics (R2 = 0.9934) and Langmuir isotherm (R2 = 0.9906); the maximum adsorption capacity was 52.7 mg/g. Conclusion: According to the obtained results, pistachio sawdust can be used as a suitable adsorbent; it can replace the common expensive and costly adsorbents.