Assessment of activated sludge stability in lab-scale experiments

作者：Van den Broeck Rob M R; Van Impe Jan F M; Smets Ilse Y M^*

来源：Journal of Biotechnology, 2009, 141(3-4): 147-154.

DOI：10.1016/j.jbiotec.2009.02.019

• Activated Sludge stability
• Biological wastewater treatment
• Transient
• Microscopic analysis
• Specific oxygen uptake rate

The majority of activated sludge research is conducted in a laboratory environment with, most often, the start-up sludge being taken from a large-scale wastewater treatment plant. Inoculating this sludge in a lab-scale set-Lip induces a transient period, which, evidently, has a direct impact on the experimental results during this period of acclimatization. In the currently published literature, the acclimatization period is either neglected or fixed to two or three times the sludge age, without any guarantee that stable conditions are indeed reached. To develop a strategy that assesses the stability of activated Sludge, three experiments were performed during which the activated sludge was extensively monitored through a series of physical, microscopic and biochemical analyses. It is demonstrated that it is possible to objectively quantify activated sludge stability through the monitoring of the total averaged filament length per image, the sludge volume index and the maximum specific oxygen uptake rate. Hereto, a moving window approach is adopted: within a 7 days interval the mean slope and the gap between the maximum and minimum value has to be smaller than a pre-specified threshold value. Once stability is reached, the true impact of test conditions can he studied without interference of adaptation phenomena.

• 出版日期2009-5-20