Application of Activated Sludge Model No. 3 for the Modeling of Organic Matter Biodegradation at Thermophilic Temperatures

Abstract

The primary aim of our research was to investigate the applicability of activated sludge models (ASM) for aerobic thermophilic processes, especially autothermal thermophilic aerobic digestion (ATAD). The ASM3 model (Gujer et al., 1999) theoretically seems to be the most suitable, because storage plays an important role in a batch-feed cycle system like ATAD. The ASM3 model was extended with an activation step of the thermophilic organisms. This model was calibrated and verified by independent test results, demonstrating its ability to describe the process. The growth (l H 5 26.04 day 21 ), storage (k STO 5 20.39 day 21 ), hydrolysis (k H 5 11.15 day 21 ) and decay rates (b H,O2 5 1.28 day 21 , b STO,O2 5 1.10 day 21 ) obtained from calibration are significantly higher at 558C than at mesophilic temperatures, justifying the faster metabolism at higher temperatures. An inert fraction of the biomass (characterized by the model parameter f I 5 0.4) was found to be significantly greater than in the mesophilic case. This can be attributed to the lower diversity of the thermophilic species and thus to their narrower substrate spectra. Water Environ. Res., 79, 554 (2007).

Modeling, Instrumentation, Automation, and Optimization of Wastewater Treatment Facilities

“…Based on simulating data from 13 nitrifying-denitrifying facilities, Choubert et al (2007) proposed the following modifications to the default ASM1 parameter values: max,A = 0.45 d -1 at 10°C; b A = 0.17 and 0.13 d -1 at 20 and 10°C, respectively; and anoxic Y H = 0.54 gCOD/gCOD at 10°C. Kovacs et al (2007) extended ASM3 using an activation step for the thermophilic organisms for modeling autothermal thermophilic digestion, which was uncoupled to the rest of ASM3, and calibrated and verified the new model with different sets of data. Hwang and Oleszkiewicz (2007) reported that the sudden temperature decrease from 20 to 10 °C caused a 20% greater decrease of the nitrification rate than predicted by using the temperature correction factor of 1.072.…”