Gujer Willi, von Gunten Urs
Swiss Federal Institute for Environmental Science and Technology (EAWAG) and Swiss Federal Institute of Technology (ETH), Duebendorf, Switzerland.
Water Res. 2003 Apr;37(7):1667-77. doi: 10.1016/S0043-1354(02)00456-6.
Disinfection of some microorganisms is characterized by a lag-phase (a minimum required ozone exposure until disinfection occurs). This phenomenon is easy to model in laboratory batch reactors but not in continuous flow mixed reactors. This paper introduces a stochastic disinfection model where individual microorganisms are followed on their paths through full-scale reactors. Combining exponentially distributed transport processes with delayed exponential disinfection kinetics for large populations of microorganisms (up to 10,000 individuals) yields predictions which can be evaluated statistically. It could be shown that deterministic models work well for systems with good disinfection performance (more than 2 log units reduction of active microorganisms), for reactors with poor performance stochastic models have to be applied. It could be demonstrated for real reactors that Bacillus subtilis spores are poor surrogates for Cryptosporidium parvum oocysts. The differences between the two microorganisms are large for reactors that deviate significantly from plug-flow behaviour.
某些微生物的消毒具有滞后期（在消毒发生之前所需的最低臭氧暴露量）。这种现象在实验室间歇式反应器中很容易建模，但在连续流混合反应器中则不然。本文介绍了一种随机消毒模型，该模型跟踪单个微生物在全尺寸反应器中的路径。将指数分布的传输过程与大量微生物（多达10000个个体）的延迟指数消毒动力学相结合，可以得到可进行统计评估的预测结果。结果表明，确定性模型适用于消毒性能良好的系统（活性微生物减少超过2个对数单位），对于性能较差的反应器，则必须应用随机模型。对于实际反应器，可以证明枯草芽孢杆菌孢子不能很好地替代微小隐孢子虫卵囊。对于显著偏离活塞流行为的反应器，这两种微生物之间的差异很大。
