[Volatilization behavior of BTEX on different underlying materials].

Volatilization behavior of benzene, toluene, ethylb-enzene and xylene (BTEX) behaves complicatedly with different characteristics of the underlying materials. For the need to control and take precautions against volatile organic compounds (VOCs) leak and pollution, and consider the diversification of underlying materials in the area of petroleum works, the test was carried out to study the volatilization behavior of BTEX on three kinds of typical underlying materials in Zibo, Shandong, China. The studies include volatilization dynamic curves of BTEX compounds and mixture and the optimized simulation formulas for them in the base of volatilization kinetics model. The results indicated that, under the same condition, volatility speed of BTEX compounds and mixture was Benzene > Toluene > BTEX > Dimethyl-benzene > Ethylbenzene, and for the three underlying materials, the order of volatility speed was water, sand and soil in sequence. The volatility coefficient linear positive correlated with the vapor pressure, the volatility coefficient remarkably increased with the vapor pressure of BTEX compounds on all the three underlying materials. The mechanism of underlying materials acted on volatilization of BTEX were mainly shown as increasing volatility area and influence the available original (amount) of pore in the course of volatilization and spread.