Development of dymanic model for growth of nitrifiers and phosphorus removing bacteria in sequencing batch reators

本研究旨在建立一个能描述序批式反应器中营养盐去除的非稳态模型。该模型最初是基于IAWQ活性污泥模型2（ASM 2）开发的。在厌氧和好氧条件下，采用序批式反应器（SBR）进行了长期试验研究。有效体积为100 L的反应器运行三个月。将6小时的循环时间分为四个阶段，即以恒定速率进料合成废水的第一混合阶段（2.0小时）、曝气和混合阶段（3.0小时）、沉降阶段（0.5小时）和排放阶段（0.5小时）。试验中，污泥龄控制在20天左右，曝气阶段的DO浓度控制在2.5mg/l左右。利用稳态和瞬态实验数据对模型进行了标定。几个动力学参数值进行了校准，以解释在稳定状态下的出水水质。校准工作表明，出水P是非常敏感的动力学参数相关的水解和发酵过程和存储过程的PHA和聚磷聚磷的聚磷生物（PAO）。然后用校正后的模型进行了长期模拟，以研究磷在启动期间的行为。该模型较好地解释了硝化/反硝化和生物除磷过程。ASM 2模型中未考虑PAO的反硝化能力，但引入PAO的反硝化能力后，预测效果更好。在启动期间，还对活性污泥进行了醌型分析。几种醌类化合物与除磷活性有良好的相关性。然而，这是很难确定的具体物种的磷去除活性。

The purpose of this study is to develop a non-steady state model which can express nutrient removal in sequencing batch reactors. The model was initially developed based on the IAWQ Activated Sludge Model No.2 (ASM2). A long-term experimental work was also carried out with a sequencing batch reactor (SBR) under anaerobic and aerobic condition. The reactor with an effective volume of 100 L was operated for three months. The cycle time of 6 hours was divided into four phases, which were the first mixing phase (2.0hrs) with feed of synthetic wastewater at a constant rate, the aeration and mixing phase (3.0hrs), the settling phase (0.5hrs) and discharge phase (0.5hrs). In the experiment, SRT and the DO level of aeration phase was controlled at around 20 days and 2.5mg/l, respectively. Experimental data at steady state and transient phase were utilized for the model calibration. Several kinetic parameter values were calibrated to explain the effluent quality at the steady state. The calibration works revealed that effluent P were very sensitive to kinetic parameters related to hydrolysis and fermentation processes and storage processes of PHA and poly-P by phosphorus accumulation organisms (PAO). Then a long-term simulation was conducted with the calibrated model to investigate phosphorus behavior during the start-up period. The model explained the nitrification/denitrifcation and biological P-removal processes satisfactorily. A better prediction was attaind when the denitrification ability by PAO was introduced, which was not considered in the ASM2. The quinon profile analysis was also conducted for activated sludge during a start-up period. Good correlationship between several quinon species and phosphrus removal activity. However it was difficult to identify the specific species for phosphorus removal activity.