Adsorption of neutral red from aqueous solutions using waste foundry sand: Full factorial design analysis



The aim of this study is to investigate the adsorption of Neutral red dye from aqueous solution on waste foundry sand with bentonite using 23 full factorial design. The combined effect of initial dye concentration, adsorbent dosage, and contact time on the neutral red adsorption was studied. Factorial design of experiments is employed to study the effect of three factors initial dye concentration (30 and 300 mg/L), adsorbent dosage (2.5 and 20 g/L), and contact time (5 and 120 min), at two levels low and high. The results were statistically analyzed by using the student's t-test, analysis of variance and an F-test to define important experimental factors and their levels. A regression model that considers the significant main and interaction effects was suggested. The results showed that initial dye concentration is the most significant factor that affects the removal of neutral red. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1086–1095, 2014