Marsili-Libelli S, Tabani F
Department of Systems and Computers, University of Florence, Italy.
Water Res. 2002 Mar;36(5):1181-92. doi: 10.1016/s0043-1354(01)00339-6.
The aim of the paper is to assess the experimental errors arising from the operation of a closed respirometer using autotrophic biomass. A closed, intermittent-flow device has been set-up for the measurement of oxygen uptake rate (OUR) and parameter calibration. After describing the device structure and operation, the factors affecting accuracy have been assessed. Inaccuracies may be caused by two groups of parameters: design parameters, including flow rate, volume, sampling time, numerical algorithm, sample injection and environmental parameters, concerning the physicochemical conditions of the experiment, such as unwanted oxygen transfer, pH, and the influence of sludge condition on "start-up" behaviour. It is shown to what extent each of them affects the final accuracy of the OUR measurement. In the second part of the paper, the respirometric data are used to calibrate a two-step nitrification model and their impact on the accuracy of the estimation of model parameters is assessed. Confidence limits are derived for the identifiable parameter combinations and the practical identifiability assessed with the aid of trajectory sensitivity analysis.
本文旨在评估使用自养生物质的密闭呼吸仪运行过程中产生的实验误差。已搭建了一个用于测量氧摄取率（OUR）和参数校准的密闭间歇流装置。在描述了该装置的结构和操作之后，对影响准确性的因素进行了评估。不准确可能由两组参数引起：设计参数，包括流速、体积、采样时间、数值算法、样品注入；以及环境参数，涉及实验的物理化学条件，如不必要的氧转移、pH值以及污泥状况对“启动”行为的影响。展示了它们各自对OUR测量最终准确性的影响程度。在本文的第二部分，呼吸测量数据用于校准两步硝化模型，并评估其对模型参数估计准确性的影响。得出了可识别参数组合的置信限，并借助轨迹灵敏度分析评估了实际可识别性。
