Absorption and Desorption of Dissolved Petroleum Hydrocarbons Using Sands as Absorbent Material

The absorption and desorption of dissolved petroleum hydrocarbons (DPHs) in seawater are studied using sands from a bathing beach as absorbent material and 0# diesel as absorbate. The results show the absorption and desorptionof DPHs on sands fits the first-order reaction model. The rate of desorption is slower than that of absorption up to 13 times, and about 25% oil becomes residues in the sands. Thus an environmental threat may have been in existence for a long time. The absorqtion isotherms can be described as Henry's equation, and the transportation amount of DPHs from seawater to sands decreases with the increase of temperature. The absorption is of to physical absorption according to the thermodynamic analysis.