Modelling seasonal dynamics of "Microthrix parvicella"

Area of Science:

• Environmental microbiology
• Wastewater engineering
• Biotechnology

Background:

• Microthrix parvicella is a filamentous bacterium causing bulking and scumming in wastewater treatment plants (WWTPs) globally.
• Despite being identified as a specialized lipid consumer, the competitive advantages of Microthrix in activated sludge systems remain unclear.
• Understanding Microthrix proliferation is crucial for efficient WWTP operation.

Purpose of the Study:

• To develop a model explaining the seasonal variations in Microthrix abundance in a full-scale WWTP.
• To investigate the hypothesis that low temperatures reduce lipid solubility and uptake by competing bacteria.
• To provide a research tool for further investigation into Microthrix selection mechanisms.

Main Methods:

• Development of a mathematical model based on the Activated Sludge Model No. 3 (ASM3).
• Calibration and validation of the model using data from a full-scale WWTP.
• Analysis of model parameters to assess the impact of temperature on lipid availability and bacterial competition.

Main Results:

• The model successfully described the observed seasonal variations in Microthrix abundance.
• The model structure and parameters supported the hypothesis that low temperatures may favor Microthrix.
• The findings indicate a potential link between temperature, lipid solubility, and Microthrix competitiveness.

Conclusions:

• The developed model provides a valuable framework for discussing and researching Microthrix selection mechanisms.
• Temperature-dependent lipid availability is a plausible factor influencing Microthrix dominance in WWTPs.
• Further research is needed to confirm these mechanisms and refine predictive capabilities for WWTP management.