Document Type : Research Paper
Abstract
The treatment ofeffluents producedby the textile industries in Nigeria leaves much to be desiredbecause there has always been the complex problem ofeliminating the synthetic dyes in the effluents such as methylene blue (MB) that do not respondwell to the traditional cleaning mechanisms; the situation has ledto the needto explore yet another cheap alternative biosorbent (in this case palm kernel shell) to increase the potential ofthe adsorption ofthe dyes. This study explores the potential ofusing activatedcarbon derivedfrom palm kernel shells, a locally available agricultural waste, to remove MB from water solutions. The palm kernel shells were carbonisedin a muffle furnace, and adsorption experiments were optimised using the Box–Behnken design within the response surface methodology framework. Key variables, including dye concentration, adsorbent dose, andcontact time, were examinedto assess their effect on dye removal efficiency. Statisticalanalysis identifieda significant model with an F-value of53.83 and p-values less than 0.05 for all factors. Optimal conditions achieved approximately 77% dye removal at an adsorbent dose of0.75 g/100 mL, a contact time of35 minutes, and a dye concentration of133 mg/l. The regression model showed a predicted R² of0.8990 and an adjusted R² of0.9674, indicating high model accuracy. Adsorption isotherms were also analysed, with the Freundlich model fitting better (R² = 0.845) than the Langmuir model (R² = 0.754), suggesting adsorption occurs on a heterogeneous surface. Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed the presence ofactive functional groups before andafter adsorption. The study demonstrates that activatedcarbon from palm kernel shells is a practical, low-cost adsorbent for treating textile effluent containing methylene blue.
