The transient-state, multiple-species biofilm model for biofiltration processes

Area of Science:

• Environmental microbiology
• Bioprocess engineering
• Mathematical modeling

Background:

• Biofilms are complex microbial communities crucial in environmental and industrial settings.
• Existing models often lack the ability to capture dynamic changes and multiple species interactions within biofilms.
• Periodic detachment, such as backwashing, significantly impacts biofilm structure and function, particularly in drinking-water biofiltration.

Purpose of the Study:

• To introduce a novel transient-state, multiple-species biofilm model (TSMSBM).
• To integrate key features essential for simulating biofilms under time-varying conditions, including periodic detachment.
• To provide a comprehensive tool for understanding complex biofilm dynamics.

Main Methods:

• Developed the TSMSBM incorporating four biomass types (heterotrophs, ammonia oxidizers, nitrite oxidizers, inert biomass).
• Included seven chemical species (BOM, NH4(+)-N, NO2(-)-N, NO3(-)-N, etc.) and eight reactions.
• Modeled reaction-diffusion, biomass growth, decay, detachment, and flux, with options for constant or periodic detachment.

Main Results:

• The TSMSBM successfully simulates transient biofilm development and the interplay of various components.
• Demonstrated the model's capability to illustrate the roles of soluble microbial products and detachment in biomass distribution.
• Showcased how backwashing influences biofilm characteristics in drinking-water biofiltration.

Conclusions:

• The TSMSBM represents a unique advancement in biofilm modeling by synthesizing essential dynamic features.
• The model provides valuable insights into the transient behavior and performance of multi-species biofilms.
• The TSMSBM is a powerful tool for optimizing processes like drinking-water biofiltration.