Department of Civil Engineering, The University of Hong Kong, Hong Kong.
Water Sci Technol. 2010;62(10):2442-9. doi: 10.2166/wst.2010.488.
Mathematical simulation and laboratory experiments were conducted to investigate the controlling factor for aerobic sludge granulation. A model was used to describe the biomass dynamics during the granulation process. The simulation results indicate that the selective discharge of small and loose sludge flocs is the key controlling factor for granulation. In the experimental studies, tests were conducted with four batch column reactors (BCR) that were seeded with both activated sludge flocs and mature granules. Three different sludge discharge methods were tested, including unselective discharge of mixed sludge, selective discharge of small and slow-settling flocs, and selective discharge of settled dense sludge. The results show that mixed sludge discharge and discharge of dense sludge resulted in disappearance of granules from the reactors. Only selective discharge of small and slow-settling sludge flocs led to complete granulation. Small and loose sludge flocs were found to have a clear advantage over large and dense granules in substrate uptake. It can be concluded that selective discharge of loose flocs removes these competitors in suspended-growth mode from the reactors and makes the substrate more available for uptake and utilization by the biomass in attached-growth form, leading to granulation.
进行了数学模拟和实验室实验，以研究好氧污泥颗粒化的控制因素。建立了一个模型来描述颗粒化过程中的生物量动力学。模拟结果表明，小而松散的污泥絮体的选择性排出是颗粒化的关键控制因素。在实验研究中，使用四个批次柱状反应器（BCR）进行了试验，这些反应器接种了活性污泥絮体和成熟颗粒。测试了三种不同的污泥排放方法，包括混合污泥的非选择性排放、小而缓慢沉降絮体的选择性排放和沉降致密污泥的选择性排放。结果表明，混合污泥排放和致密污泥排放导致反应器中的颗粒消失。只有小而缓慢沉降的污泥絮体的选择性排放才能导致完全颗粒化。小而松散的污泥絮体在基质摄取方面明显优于大而致密的颗粒。可以得出结论，松散絮体的选择性排出将悬浮生长模式下的这些竞争生物从反应器中去除，使基质更容易被附着生长形式的生物量摄取和利用，从而导致颗粒化。
