| In this study, the activated carbons (AC) were prepared from the tung nutshell byH3PO4 activation. The method of factor analysis and the orthogonal design wereemployed to investigate the two different approaches of preparation. The preparationfactors, which effect AC's on the pore structural characteristics and the adsorptionproperties of methylene blue and iodine were discussed and optimized completely. Theresults show that the microwave radiation is a more effective method than the traditionalheating method for preparation of AC from the tung nutshell, for the preparing processtakes shorter time, and the AC prepared by the microwave radiation approach revealsexcellent adsorptive capability with evaluation of pore structure. Moreover, the highsurface area activated carbons (HSAAC) were also prepared by KOH activation using thetung nutshell-base-charcoal as the precursor. The orthogonal design method was appliedto analysis the effect preparation conditions on pore structural characteristics and theadsorption capability of phenol and methylene blue onto the prepared activated carbons.For prepared activated carbons, a specific surface area and pore size distributionanalyzer was employed to determine the N2 adsorption-desorption at 77K. The BETequation, MP and BJH methods were used to estimate the surface area, pore volume andpore size distribution. The scan electric microscope (SEM), X-ray diffraction (XRD) andFT-IR were also used to investigate the morphology, crystallite structure and chemistrystructural characteristics, respectively. The results show that all produced AC's possesmany graphite-like crystallite structure; The carbons prepared by H3PO4 activation revealmeso-porous structures with a broad pore size distribution, whereas those obtained fromKOH activation show to be the materials with predominant microporous structures and anarrow pore size distribution.The experimental results of Cr(Ⅵ) adsorption onto the tung nutshell-base-activatedcarbon show that the pH value of Cr(Ⅵ) solution is the most important factor to effect onthe Cr(Ⅵ) adsorption capacity of AC. Under the conditions of the initial pH: 2～3,concentration of Cr(Ⅵ): 40～60 mg/L, the dosage of AC: 2.0 mg/L and adsorptiontime: 180 min, the activated carbon reveals the highest adsorption capability for Cr(Ⅵ) insolution.
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