Stormwater biofilter treatment model for faecal microorganisms.

Area of Science:

• Environmental Engineering
• Microbiology
• Hydrology

Background:

• Stormwater biofilters are crucial for managing water quality.
• Understanding microbial removal in biofilters is essential for effective stormwater treatment.
• Existing models may not fully capture long-term microbial dynamics.

Purpose of the Study:

• To develop and validate a new model for simulating long-term microbial removal in stormwater biofilters.
• To assess the impact of different biofilter configurations on microbial transport and fate.
• To identify key factors influencing microbial removal efficiency.

Main Methods:

• A 'three-bucket' approach for water flow and a one-dimensional advection-dispersion equation for microbial transport.
• Incorporation of adsorption, desorption, die-off, and temperature effects on microbial removal.
• Model calibration and validation using long-term monitoring data from laboratory columns.

Main Results:

• The water flow module achieved high efficiency (Nash-Sutcliffe Efficiency E: 0.82–0.95).
• The microbial quality module showed moderate to good performance (E: 0.46–0.68) for Escherichia coli removal.
• Sensitivity analyses indicated potential data limitations impacting model predictions.

Conclusions:

• The developed model provides a valuable tool for simulating microbial removal in stormwater biofilters.
• Optimized parameters align with existing literature, but further data is needed for robust calibration.
• Future research should focus on acquiring more comprehensive datasets to enhance model accuracy and reduce uncertainties.