关键词: 土壤, 石油烃, 热脱附, 加热温度, 保持时间, 负压

Abstract: The effects of heating temperature, retention time and vacuum conditions on the thermal desorption process of the fractions of petroleum hydrocarbon in soil were investigated by simulating the thermal desorption process in a tubular furnace, which provided a theoretical basis for the actual petroleum hydrocarbon contaminated soil. The results showed that increasing the heating temperature, prolonging the retention time, and providing negative pressure conditions had positive effects on improving the removal rate of total petroleum hydrocarbons(TPH) in soil. Keeping the temperature at 250 °C for 2.0 h or at 300 °C for 1.0 h, the removal rate of petroleum hydrocarbons was over 97%, and the residue amount of TPH was lower than the risk screening value of the first type of land in “Soil environmental quality：Risk control standard for soil contamination of development land” GB 36600-12018. The removal rates of C₁₀-C₁₆，C₁₇-C₂₈ and C₂₉-C₄₀ fractions were lower than 40% at 150 ℃ for 1.0 h, and C₁₀-C₁₆，C₁₇-C₂₈  fractions in soil could be quickly and effectively removed at 250 ℃. The removal efficiency of C₂₉-C₄₀ fractions was the key to reach the goal of remediation, because C₂₉-C₄₀ fractions were obviously affected by heating temperature and retention time.

Key words: soil, petroleum hydrocarbons, thermal desorption, heating temperature, retention time, negative pressure