土壤中分段石油烃热脱附行为研究

采用管式炉模拟土壤中石油烃热脱附过程,考察了加热温度、保持时间以及负压条件对土壤中分段石油烃热脱附过程的影响,为实际石油烃污染土壤修复工作提供理论依据.结果表明:提高加热温度、延长保持时间以及提供负压条件均对提高土壤中总石油烃去除率产生积极作用;常压下,在250℃保持2 h与300℃保持1 h的条件下,土壤中总石油烃去...

THERMAL DESORPTION BEHAVIOR OF THE FRACTIONS OF PETROLEUM HYDROCARBONS IN SOIL

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.