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地下水曝气修复MTBE污染土壤过程中物化参数的确定

Keywords: Air,sparging,MTBE,土壤修复,吸附常数,有效扩散系数,相间传质系数

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Abstract:

采用吸附实验,研究了地下水曝气(airsparging,AS)修复MTBE污染土壤过程中MTBE在不同颗粒度的石英砂下的吸附参数、有效扩散系数和相间传质系数。结果表明,Freundlich等温吸附方程可以很好地描述MTBE在石英砂中的吸附行为,并且由此算出的粗砂,混合砂和细砂的吸附常数K随着颗粒度的减小相应增大,依次为6.855E-04、1.854E-03和1.910E-03。在有效扩散系数的计算中,本文用扩散模型拟合出MTBE在干燥土壤中的有效扩散系数Deff=3.748×10-6m2·s-1,并且拟合回归参数R2=0.997,非常接近1.0,这表明本实验采用的方法可以可靠地确定有机物在土壤中的有效扩散系数。在相间传质系数的分析中,本文采用经验公式计算出MTBE(NAPL)-水-气三相在土壤中的相间传质速率系数,计算结果表明,NAPL-水相平衡可看作瞬态平衡过程,并且相间传质速率常数主要取决于砂子的比表面积,而在气-水相和NAPL-气相中,它们的相间传质速率系数与空隙率有关。

References

[1]  Happel A M, Beckenbach E H, Halden R U. An evaluation of MTBE impacts to California groundwateFresources, Lawrence Livermore National Laboratory. Environmental Protection Department, Environmental Restoration Division, University of California. UCRL-AR- 130897. 1998.
[2]  Liu S J, Jiang B, Huang G Q, et al. Laboratory column study for remediation of MTBE-contaminated groundwater using a biological two-layer permeable barrier[J]. Water Research, 2006,40(18): 3401 - 3408.
[3]  Hartley W R, Englande A J, Harrington, D J. Health risk assessment of groundwater contaminated with methyl tertiary butyl ether (MTBE)[J]. Water Science and Technology, 1999,39(10-11): 305-310.
[4]  Kim H, Armable M D. Effect of surface tension reduction on VOC removal during surfactant-enhanced air sparging [J]. Journal of Environmental Science and Health, Part A -Toxic/Hazardous Substances and Environmental Engineering, 2006,41(12): 2799-2811.
[5]  李凌.土壤气相抽提法(SVE)去除土壤中挥发性有机污染物的研究[M].天津:天津大学,2002.
[6]  Schmidt T C, Schirmer M, Weiss H, et al. Microbial degradation of methyl tert-butyl ether and tert-butyl alcohol in the subsurface[J]. Journal of Contaminant Hydroaraphy, 2004,70(3-4): 173-203.
[7]  Chao K P, Ong S K, Protopapas A. Water-to-air mass transfer of VOCs laboratory-scale air sparging system[J]. Journal of Envlronmental Engineering,1998,124(11): 1054-1060.
[8]  Schwazenbach R P, Gschwend, P M, ImbodenD M. Environmental organic chemistry, John Wiley and Sons, Inc,1993.
[9]  Wilkins M D, Abriola L M, Pennell K D. An experimental investigation of rate-limited nonaqueous phase liquid volatilization in unsaturated porous media: steady state mass transfer[J]. Water Resource Research, 1995, 31(9): 2159-2172.
[10]  Powers S E, Nambi I M, Curry G W. Non-aqueous phase liquid dissolution in heterogeneous systems: Mechanisms and a local equilibrium modeling approach[J]. Water Resource Research,1998,34(12): 3293- 3302.
[11]  Giles H, TH MacEwan, SN NaKhwa. Studies in adsorptiom[J].J Chem Soc, 1960,111:3973-3993.

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