Artocarpus camansi Blanco (Breadnut) core as low-cost adsorbent for the removal of methylene blue: equilibrium, thermodynamics, and kinetics studies

This study investigates the adsorption characteristics of methylene blue (MB) on core of breadnut, Artocarpus camansi Blanco. Oven-dried Artocarpus camansi core (ACC), with point of zero charge at pH 4.1, was found to be very effective in removing MB when compared to most literature reported fruit biomasses. Six isotherm models coupled with error analyses were used to investigate possible models of adsorption. Both the Langmuir and Sips models were found to give the best fit with maximum adsorption capacity, measured as mg of MB per g of adsorbent, of 369 and 328 mg g−1, respectively. Thermodynamics studies showed that the adsorption process was both spontaneous and exothermic. Fast kinetics, with 50% MB being removed within 5 min when 50 mg L−1 dye solution was used, showed pseudo-second-order. Fourier transform infrared, X-ray fluorescence, and scanning electron microscopic investigation of ACC before and after MB adsorption conclusively demonstrated that oven-dried breadnut core has great potential to be used as a low-cost adsorbent for the removal of MB.