<p>The development of low-cost and sustainable adsorbents for wastewater treatment has gained significant attention due to increasing environmental pollution caused by industrial waste such as dyes. The motivation of the present investigation is to utilize the waste from the <i>Manihot esculenta</i> tuber, commonly called tapioca or cassava. The discarded peel is used for the preparation of activated carbons. The conventional activation includes chemical and thermal processes that require long processing times, substantial energy and chemical inputs which may sometimes negatively affect the quality of the activated carbons. In this study, porous carbon was prepared from tapioca peel, an inexpensive and abundantly available agricultural by-product, through microwave-assisted activation (MWTPC), and its methylene blue adsorption was systematically compared with that of thermally activated carbon (TATPC). Batch-mode adsorption studies with methylene blue (MB) as the model adsorbate were performed to investigate the influence of contact time, adsorbent dosage, concentration, temperature, and solution pH on adsorption efficiency. Adsorption kinetics were analyzed using the pseudo-second-order model. MWTPC showed greater adsorptive capacity of 238 mg g^-1 and the highest rate constant of 0.012&#xa0;g mg^-1 min^-1, which is ten times higher than that of TATPC. Results of the Freundlich and Langmuir adsorption isotherms were determined and discussed in detail. Isotherms also showed superior performance for microwave-activated carbons. MWTPC showed enhanced adsorption at a smaller dosage of 2&#xa0;g g^-1. Thermodynamic parameters such as enthalpy(∆H), Gibbs free energy(∆G), and entropy(∆S) were calculated, and adsorption was found to be more feasible at all temperatures. The adsorbents were characterized using FTIR and SEM analysis. Studies showed the distinct characteristics of the adsorbents, enhanced adsorption capacity, and improved feasibility as a result of microwave activation.</p>