An experiment was conducted to compare the adsorption capacity and characteristics between activated carbon made of rice-hull(RHAC) and F-400 by Calgon to remove phenol, heavy metal and ammonia-nitrogen. While F-400 could not remove ammonia-nitrogen, RHAC was able to adsorb it. This is considered to be due to the ionic sorption capability of SiO2 remaining on the surface of RHAC. From the sorption equilibrium test, it was found that RHAC has higher adsorption capacity than F-400. In column tests, the slope of breakthrough curves of RHAC which represent the affinity of an adsorbent, was observed to be more gradual than F-400. This may be attributed to the inner diffusion of adsorbent once attached on macropores, into micropores well developed, with higher specific surface area of RHAC than F-400. For heavy metals, F-400 would remove chromium and lead but not cadmium, whereas RHAC was able to remove cadmium, lead but not chromium. This phenomenon is considered to have something to do with the distinct surface functional group of RHAC and the various surface charge densities of heavy metals tested.

An activated carbon-impregnated cellulose filter was fabricated, and the capacity to remove dust and volatile organic compounds was evaluated in a laboratory. The adsorption capacities for benzene, toluene, ethyl benzene and m-xylene gases were compared by an adsorption isotherm test conducted as a preliminary test, showing that mxylene and benzene were the most and least favorable for adsorption onto activated carbon, respectively. Cellulose filters were made with four levels of activated carbon contents, and dust removal was performed with all of the filters showing 99 % and higher efficiencies stable with a small variation during the experiment. Activated carbon content of 5 g in the unit filter area (125 g/m 2 ) was found optimum for benzene, toluene, ethylbenzene and m-xylene removal, as it appeared that higher than 5 g activated carbon content was unnecessary for the improvement of its capacity. With increasing benzene, toluene, ethylbenzene and m-xylene loading, the highest removal rates were determined as 0.33-0.37 mg/cm 2 s for as short as 0.0046 s of air filter residence time. The rapid removal was possible because of the high surface area of the activated carbonimpregnated cellulose filter provided by powdered activated carbon, which is distinguished from the granular form in conventional activated carbon towers. As fixed within a cellulose scaffolding structure, the powdered activated carbon performed excellent benzene, toluene, ethylbenzene, and m-xylene adsorption (98.9-100 %), and at the same time, particular matters were removed in average 99.7 % efficiency after being filtered through the cellulose filter sheet.

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