Thesis (B.S.) -- Cagayan State University, 2023.
Includes bibliographical references.

The study produced an activated carbon derived from sweet potato peels (SPAC), impregnated with 60 % (v/v) phosphoric acid (2:1), and carbonized at 400 °C, 500 °C, and 600 °C for 60 minutes. A batch sorption study is done to investigate the effect of carbonization temperature on the removal efficiency and adsorption capacity of produced SPAC. The physicochemical characteristics of the activated carbon produced at varying carbonization temperatures were compared in terms of fixed carbon content, moisture content, volatile matter, and ash content using proximate analysis, and the functional groups using Fourier transform infrared (FTIR). The surface morphological characteristics and elemental composition of SPAC carbonized at 600 °C were studied using scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The results of the batch sorption study revealed that SPAC-600 and SPAC-500 exhibited comparable adsorption capacity and dye removal efficiency, higher than SPAC-400. The sweet potato peel is a highly promising adsorbent for methylene blue dye remediation with adsorption capacities and removal efficiencies of 49.97 mg/g and 99.94% for SPAC-600, and 49.97 mg/g and 99.87% for SPAC-500, at 100 mg/L of adsorbate dosage, 0.5 g/250 mL of adsorbent dosage, and 40 minutes contact time. Langmuir, Freundlich, and Dubinin-Radushkevich isotherm modeling were carried out. Langmuir isotherm gave a better fit for SPAC-400 and SPAC-600 while SPAC-500 fitted the Freundlich Isotherm model better. The maximum loading capacity (qmax) for SPAC-400, SPAC-500, and SPAC-600 was 38.87, 50.98, and 53.31 mg/g with R2 values of 0.9945, 0.9844, and 0.9798, respectively. The mean energy (E) calculated using Dubinin-Radushkevich isotherm for SPAC-400, SPAC- 500, and SPAC-600 is in the range of 1-8 kJ/mol, indicating that the governing type of adsorption is physical. The kinetics was evaluated using pseudo-first order and pseudo- second order kinetic models, where the data was best described by pseudo-second order, suggesting that the rate-limiting step is chemisorption.

Keywords: Activated carbon, sweet potato peels, phosphoric acid, adsorption.