Removal of basic dyes from aqueous solution using sugarcane bagasse: optimization by Plackett–Burman and Response Surface Methodology

Abstract

In the present study, Plackett–Burman design has been used to identify the significant factors affecting the removal of basic dyes using agricultural waste, sugarcane bagasse (natural sugarcane bagasse). The effect initial dye concentration and sorbent dosage were identified to be the variables responsible for affecting the percentage uptake of Basic Blue 3 (BB3) and Methylene Blue (MB) from aqueous solution. Meanwhile, none of the studied variables were found to be significantly affecting the percentage uptake of Basic Yellow 11 dye. The interaction between the factors and their optimum levels for maximum percentage uptake of dyes were determined using Response Surface Methodology. Both models were highly significant with correlation coefficients (R²) of 0.9947 and 0.9967 for BB3 and MB dye solutions, respectively. For BB3, the percentage uptake of 98.59 was obtained with optimized conditions at 50 mg L⁻¹ initial dye concentration and 0.13 g sorbent dosage. Whereas for MB, under the optimum of 72 mg L⁻¹ of initial dye concentration and 0.18 g of sorbent dosage, the percentage uptake was recorded to be 95.19. The experimental values agreed well with the predicted values with percentage errors less than 3%.

Keywords:

• Dyes
• Low-cost adsorbent
• Adsorption
• Statistical experiments
• Optimum conditions

Acknowledgments

The authors are thankful for the support by the International Foundation for Science, Stockholm, Sweden and the Organization for the Prohibition of Chemical Weapons, The Hague, the Netherlands via grant number W/4386-1 and teaching assistantship for E.C. Khoo by Universiti Tunku Abdul Rahman (UTAR).