A Multi-Parameter Sensitivity Analysis of a Model Describing the Fate of Volatile Organic Compounds in Trickling Filters

A frequency array technique was employed to assess the impact of process operating and design conditions, biofilm, and compound-specific properties on the fate of volatile organic compounds (VOCs) in trickling filter processes. The objective of the study was to identify the ranges of parameters over which model predictions of biodégradation, volatilization, and overall removal are particularly sensitive. The model was found to be most sensitive to liquid loading rates less than 20 m³/m²-d and gas loading rates less than 200 m³/m²-d. The model predictions indicate that an effective method for controlling VOC emissions is through control of trickling filter ventilation rates. Effluent recycle had only marginal impact on model predictions. Model predictions were most sensitive to biofilm thickness less than 1 x 10^-4 m, liquid-gas mass transfer coefficients less than 0.10 m/d, Henry's law coefficients less than 0.10, and biodégradation rate coefficients less than 20 m³/kg-d. When employing the model for predictive purposes, greater care should be taken in defining parameters for compounds that lie within these ranges.