Extraction of methylene blue using palm kernel oil as a green organic solvent: a parametric study

Methylene blue (MB), a synthetic dye widely used in industries such as textiles, pharmaceuticals, and food processing, has become a major environmental pollutant due to its toxicity and persistence in aquatic environments. Conventional solvent extraction methods often rely on hazardous organic solvents, posing risks to both human health and the environment. This study investigates a sustainable alternative by using palm kernel oil (PKO), a green organic solvent, for MB extraction. A parametric study was conducted to evaluate the effects of pH, organicto-aqueous volume ratio, and initial MB concentration on extraction efficiency. Batch extractions were performed using the shake-out method. The results showed a maximum extraction efficiency of 99% at pH 4.6 and a 1:1 volume ratio. Extraction efficiency was also influenced by the initial dye concentration. Additionally, a stripping process using hydrochloric acid (HCl) achieved 99% recovery of MB from the PKO phase, enabling solvent reuse. The presence of MB in PKO was confirmed using FTIR analysis. This study highlights PKO’s potential as a greener and effective alternative to conventional solvents in dye removal, offering a safer and more sustainable approach.