Abstract: In this article we determinated the adsorption rate of oil bleached by different adsorbents at 475nm wavelength. From the isosteric adsorption values the bleaching effects of activated carbon were compared with different activated attapulgites wich three kinds of pore size distributions(C2, C3, C4). The adsorption characteristics of this new kind of absorbent- attapulgites used in this bleaching process were investigated. The results showed that activated attapulgites are better than the activated carbon in processing colors adsorption. At the same time, this article compared the specific surface area and pore size distribution of these different adsorbents to elucidate that the specific surface area only can’t decide the bleaching effect. The more the polarity of the adsorbents close to the color particles and the pore diameter of the adsortents similar to the molecular diameter of the adsorbate, the more adsorption happen.

Key words: carbon, attapulgites, colors, specific surface area, pore size distribution, Freundlich