Woo S H, Park J M, Rittmann B E
Department of Civil Engineering, Northwestern University, Evanston, Illinois, USA.
Biotechnol Bioeng. 2001 Apr 5;73(1):12-24. doi: 10.1002/1097-0290(20010405)73:1<12::aid-bit1032>3.0.co;2-w.
This work develops and utilizes a non-steady-state model for evaluating the interactions between sorption and biodegradation of hydrophobic organic compounds in soil-slurry systems. The model includes sorption/desorption of a target compound, its utilization by microorganisms as a primary substrate existing in the dissolved phase, and/or the sorbed phase in biomass and soil, oxygen transfer, and oxygen utilization as an electron acceptor. Biodegradation tests with phenanthrene were conducted in liquid and soil-slurry systems. The soil-slurry tests were performed with very different mass transfer rates: fast mass transfer in a flask test at 150 rpm, and slow mass transfer in a roller-bottle test at 2 rpm. The results of liquid tests indicate that biodegradation of the soil-soluble organic fraction did not significantly enhance the biodegradation rate. In the slurry tests, phenanthrene was degraded more rapidly than in liquid tests, but at a similar rate in both slurry systems. Modeling analyses with several hypotheses indicate that a model without biodegradation of compound sorbed to the soil was not able to account for the rapid degradation of phenanthrene, particularly in the roller-bottle slurry test. The model with sorbed-phase biodegradation and the same biokinetic parameters, but unique mass transfer coefficients, simulated the experimental data in both slurry tests most successfully. Reduced mass transfer resistance to bacteria attached to the soil is the most likely phenomenon accounting for rapid sorbed-phase biodegradation.
本研究开发并利用了一种非稳态模型，用于评估土壤浆液系统中疏水性有机化合物的吸附与生物降解之间的相互作用。该模型包括目标化合物的吸附/解吸、微生物将其作为溶解相以及生物量和土壤中吸附相存在的主要底物的利用情况、氧传递以及作为电子受体的氧利用情况。对菲进行了液体和土壤浆液系统中的生物降解试验。土壤浆液试验在非常不同的传质速率下进行：在150转/分钟的摇瓶试验中传质快，在2转/分钟的滚瓶试验中传质慢。液体试验结果表明，土壤可溶性有机组分的生物降解并未显著提高生物降解速率。在浆液试验中，菲的降解比液体试验中更快，但在两种浆液系统中的降解速率相似。基于多种假设的建模分析表明，一个不考虑吸附在土壤上的化合物生物降解的模型无法解释菲的快速降解，特别是在滚瓶浆液试验中。具有吸附相生物降解且生物动力学参数相同但传质系数独特的模型，最成功地模拟了两种浆液试验中的实验数据。降低附着在土壤上的细菌的传质阻力是吸附相生物降解快速发生的最可能原因。
