The paper presents advantages and limitations of microwave heating in preparation of lotus stalk-based activated carbon by comparing the characteristic and adsorption properties of carbons with microwave (Mic-LSAC) and conventional (LSAC) heating methods employing H3PO4 as chemical agent. Mic-LSAC was produced with radiation power of 700W and radiation time of 15 min. LSAC was allowed by single step to get carbonized at 450 degrees C in a muffle furnace for 1 h. Both produced carbons showed typical Type IV nitrogen adsorption isotherms. Mic-LSAC had large surface area of 1434 m(2)/g and micropore volume of 1.337 cm(3)/g, while LSAC had surface area of 1220 m(2)/g and micropore volume of 1.191 cm(3)/g. Moreover, Mic-LSAC had higher portion of mesopores than LSAC. Boehm's titration results and Fourier transform infrared spectra indicated that Mic-LSAC possessed smaller acidic oxygen functionalities. Mic-LSAC had higher pH(pzc), more ordered stacking of layer compared to LSAC. For both adsorbents, the adsorption kinetics followed the pseudo-second-order model and the adsorption equilibrium data were very well represented by the Langmuir isotherm. The maximum adsorption capacities obtained at pH 2.80 were 564.97 mg/g and 537.63 mg/g for Mic-LSAC and LSAC, respectively. The differences of textual and chemical characteristics caused by heating method were related to adsorption capacity. (C) 2011 Elsevier B.V. All rights reserved.