Linear and nonlinear modeling of kinetics and isotherm of malachite green dye adsorption to trimellitic-modified pineapple peel

Adsorption is known for toxic dye removal in water, which can utilize a plant-based material to make a low cost and sustainable adsorbent. This study addresses the issue of preparing a cellulose-based adsorbent that is catered to cationic dye property and address inaccurate data interpretation and parameter estimation errors in adsorption analysis. The objective of this research is to overcome these challenges by modifying the surface of cellulose with carboxyl and utilizing original nonlinear equations with errors evaluation within the applied models to interpret the adsorption. In this paper, the pineapple peel cellulose will be reacted with 1,2,4–benzene tricarboxylic acid for malachite green adsorption. Characterization results showed a peak of C = O at 1712 cm-1, confirming the success of the modification. Through analyzing lowest sum of normalized error in linear and nonlinear model fitting, the best fit was obtained from the nonlinear Sips isotherm, with qm = 51.3 mg g-1, KS = 0.016 L/g, and 1/n = 2.0, as well as PSO kinetics k2 = 0.0142 g mg-1 min-1, qe = 24.8 mg g-1 which suggest that the modification of cellulose promotes collaborative adsorption, a mixing mechanism for MG dye adsorption.