| Summary: | 碩士 === 元智大學 === 化學工程研究所 === 88 === Petrochemical and other chemical products are important parts of mainstay requires in our life. However, manufacturing of these products very often can cause severe soil or groundwater pollution problems. Due to its complex structure, remediation of soil contaminated by organic compounds has never been easy. In the present experimental research, thermal desorption is considered as a means for remediating soil contaminated by benzene, toluene, ethylbenzene and xylene (BTEX) which are common organic compounds found in the petrochemical industries.
In the batch experimental tests, the desorption temperature were chosen to be around respective boiling points of BTEX. Based on the chosen temperature, experimental tests were conducted to gather data for establish the desorption isothermal Langmuir model was found to describe quiet well the observed data. On the mass transfer aspect, a power type mass transfer model was proposed to represent the mass transfer process.
In the continuous desorption tests, the contaminated soil was transported in a screw heating bed to achieve thermal detachment of organic compounds from soil. Test runs were conducted to investigate the thermal desorption efficiencies of contaminated soil under various operating conditions of temperature, gas flow rate, soil loading and initial organic concentration. Proper conditions were indentified for efficient operation of the thermal desorption process.
The test results idicated that among the four compounds tested, benzene is the easiest to remove from the contaminated soil by xylene, ethylbenzene and toluene. Thermal desorption was found to be a highly efficient process for removal of BTEX or similar compounds.
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