Development of Composite Adsorptive Biosorbent from \(H_3PO_4-NaOH-BaCl_2\) Modified Almond Shell: Experimental and Statistical Approach

This study aimed to use an experimental and statistical approach to develop a cost-effective composite adsorptive biosorbent from acid, base and salt-modified biomass. Almond Shell samples were washed, milled to uniform particle sizes (425 µm) and then modified with H3PO4, NaOH, and BaCl2 separately. The three active samples were combined to form a tricomposite biosorbent based on the Simple Lattice Design (SLD) under the Mixture Methodology of the Design Expert Software (11.0.1), within the ranges of 20-60%. The adsorptive capacity of each within tricomposite consisting of different percentage compositions of the modified Almond shell samples was investigated based on the Methylene Blue Number (MBN) Test. The results obtained were subjected to statistical analysis. The maximum adsorption capacity (MBN) of 896.12 mg/g was obtained from the tricomposite almond shell comprising mixture ratio of 20% (H3PO4), 20% (NaOH) and 60% BaCl2. The combination is well fitted to Linear Model () with Std. Dev. of 13.25, R² of 0.6452, Adjusted R² of 0.5565, Predicted R² of 0.4566 and Adeq Precision of 8.472 (>4). The numerical optimization of the experimental data was obtained at 0.980 desirability. The experimental values obtained were in good agreement with the predicted values from the models, with relatively small errors (0.13%) between the predicted and the actual values. This shows that the optimisation process via the SLD was very fit and reliable.