Schoefs O, Perrier M, Samson R
Department of Chemical Engineering, Université de Technologie de Compiègne, BP 20 529, 60205 Compiègne Cedex, France.
Appl Microbiol Biotechnol. 2004 Mar;64(1):53-61. doi: 10.1007/s00253-003-1423-3. Epub 2003 Dec 5.
The objective of this study was to develop a reduced-order model of biodegradation in unsaturated soils that allows the estimation of contaminant depletion, using available on-line measurements. Hexadecane was chosen as a model compound for petroleum hydrocarbons. A two-compartment model was developed, decoupling the intrinsic biodegradation kinetics from limiting factors imposed by field conditions, such as oxygen transfer and contaminant bioavailability. Two new experimental protocols (one for the liquid phase and the other for the solid phase) were developed to monitor hexadecane depletion, hexadecane mineralization, total mineralization, and evolution of the degraders. Using the liquid-phase experiment, parameters of a Haldane kinetic model and yield coefficients were identified and used in the complete model of biodegradation in soil. Using the carbon dioxide production curve, a biocontact kinetic model was identified so that, despite the high sensitivity of the model outputs to variations in the parameters, hexadecane depletion could be correctly predicted with an average error on the entire time trajectory of about 8%. Moreover, the ratio between hexadecane mineralization and total mineralization remained constant after a brief transient period, indicating that hexadecane mineralization could be deduced from the total carbon dioxide measurement. Finally, the new model developed in this study allows real-time monitoring of contaminant biodegradation, using on-line carbon dioxide measurement.
本研究的目的是建立一个非饱和土壤中生物降解的降阶模型，该模型能够利用现有的在线测量数据估算污染物的消耗情况。选择十六烷作为石油烃的模型化合物。开发了一个双室模型，将内在生物降解动力学与现场条件（如氧气传递和污染物生物可利用性）施加的限制因素解耦。制定了两个新的实验方案（一个用于液相，另一个用于固相）来监测十六烷的消耗、十六烷的矿化、总矿化以及降解菌的演变。利用液相实验，确定了哈代动力学模型的参数和产率系数，并将其用于土壤生物降解的完整模型。利用二氧化碳产生曲线，确定了一个生物接触动力学模型，这样，尽管模型输出对参数变化高度敏感，但在整个时间轨迹上，十六烷消耗的预测平均误差约为8%时仍能正确预测。此外，经过短暂的瞬态期后，十六烷矿化与总矿化的比值保持恒定，这表明十六烷矿化可以从总二氧化碳测量值中推导出来。最后，本研究开发的新模型能够利用在线二氧化碳测量实时监测污染物的生物降解情况。
