| Polycyclic aromatic hydrocarbons (PAHs) are a large group of substances with carcinogenicity, reproductive toxiciry, embryotoxicity and teratogenicity, and they have been found widely distributed It is necessary to investigate the sorption characteristics of PAHs in water by soil.In this paper, the sorption properties, mechanisms and characteristics of PAHs by soil were studied experimentally using batch reactor and continuous-flow column. Batch reactor experiments showed the removal of organic pollutants with unsaturated bond by soil attributed to solute partition, the partition process finished quickly, and temperature had little effect on the process and sorption capacity. The removal efficiency of PAHs by soil was significant. The sorption of Acenaphthene and Phenanthrene was characterized by linear isotherm, indicating solute partition between water and the organic phase in soil. As of organic pollutants with unsaturated bond, the .sorption capacity of soil was greatly less than that of PAC. The removal ratios of different PAHs by soil increased with molecular weight and cyclic number, while those by PAC were high and stable.The continuous-flow column test indicated that the removal efficiency of PAHs by soil was significant in all those fixed-bed and the removal ratios of different PAHs increased with molecular weight and cyclic number The results of continuous-flow column test consisted with those of batch reactor. There was not a typical sorption layer of organic pollutants with unsaturated bond, but there was a high available sorption capacity which increased with the empty-bed contact time.
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