This research applied microwave-induced plasma with KOH activation to obtain activated carbon. It was discovered that activated carbon with a large surface area can be synthesized by this treatment in an extremely short time, where activated carbon with a Brunauer–Emmett–Teller surface area of 1007, 1888, 2084 m2 g−1 was obtained within 80, 270, 330 s, respectively. It is remarkable that the investigated method can reduce the activation time by one to two order of magnitude in comparison to conventional thermal activation. Emission spectra from the plasma and pore structures of the products depending on KOH concentration are discussed here.

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Oxy-tetracycline (OTC) has been recognized as not only a good antibiotic but also environmental contamination resulted from over-dosage and leakage from agricultural activities. Among various alternatives, catalytic ozonation is a promising method because of its simplicity and effectiveness. In this work, magnetic carbon nanoparticles (M-CNPs) synthesized by nebulizing pyrolysis of glycerol and ferrocene has been applied as a catalyst for enhancing ozonation of OTC. Effects of catalyst loading and initial concentration of tetracycline on degradation of oxy-tetracycline have been experimentally examined in comparison with other typical carbonaceous powders which are carbon black and graphite. While the change of OTC concentration were analyzed using high performance liquid chromatography (HPLC) analyzer for examining its characteristics, fresh and spent carbonaceous catalysts were also characterized using electron microscopy, surface area and porosity analyzer, and x-ray diffraction (XRD) analyzer. It was found that M-CNPs could exhibit a superior performance in the removal of OTC by adsorption and catalytic ozonation, resulting a faster completion of OTC removal within 30 min or 2 times faster when compared with the cases of carbon black and graphite powder as well as ozonation alone.

A new activation method using a pseudo continuous reactor with microwave-induced plasma is examined to prepare activated carbon. Carbonized carbon gel is mixed with potassium hydroxide before being activated by microwave irradiation. The specific surface area of the product is investigated by varying microwave-retention time. The results show that the activated carbon with specific surface area of 3,054 m 2 g -1 and total pore volume of 1.35 cm 3 g -1 can be obtained within 510 s, although hour-level time is necessary to obtain similar activated carbon if conventional methods are used. Temperature change of the carbon precursor caused by microwave irradiation was measured in batch mode to estimate the temperature at pseudo continuous system based on the retention time. It was found that the retention time to reach 700 °C of the carbon precursor can be essential factor to achieve high surface area and large pore volume. In addition, the activated carbon synthesized by the proposed method can show an average mass yield percentage of 24.2%, which is much higher than that from conventional methods, 4.5-5.0%. Based on the influence of the microwave retention time, reaction mechanism is discussed. The fast rate and high yield shown here should contribute to energy-saving process.