热强化有机污染物自土中挥发过程的试验与理论研究
Experimental and theoretical studies on volatilization process of heat-enhanced organic pollutants from soils
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摘要: 为了研究热强化条件下有机污染物自土中挥发去除规律及挥发过程的影响因素,设计了室内挥发模型试验,研究了不同温度、不同初始污染物浓度的挥发去除规律。研究结果表明,有机污染物自土中的挥发过程曲线可分成三个阶段:快速挥发期,稳定增长期和平衡挥发期;另外,初始污染物浓度越大,自由相污染物分子的比例越高,挥发速率越大;温度由40℃升高至80℃时,砂土的平均挥发速率提高了4.0~4.8倍;综合考虑拟合方程的相关性发现,有机污染物自土中的挥发去除过程符合一级动力学模型。Abstract: In order to study the laws of volatilization removal of organic pollutants from soils and the influencing factors of volatilization process under heat-enhanced conditions, the indoor volatilization model experiments are designed. The laws of volatilization removal at different temperatures and initial pollutant concentrations are studied. The results show that the volatilization process curve can be divided into three stages: fast volatilization stage, stable growth stage and balanced volatilization stage. In addition, the higher the initial concentration of pollutants, the higher the proportion of free-phase pollutants, so the rate of volatilization is getting faster. When the temperature increases from 40℃ to 80℃, the average volatilization rate of sand increases by 4.0 to 4.8 times. Considering the correlation of the fitting equation, the volatilization process of organic pollutants from soils conforms to the first-order kinetic model.