Deep-biofilm kinetics of substrate utilization in anaerobic filters

Acetate fermentation in anaerobic filters was performed to study the deep-biofilm kinetics of substrate utilization. Small Peclet number ranging from 0.01 to 1.5 found in the tracer test indicates that the flow regime in anaerobic filters is close to complete-mix. An axial dispersion model coupled with deep-biofilm kinetics is simulated along the biofilter height. A good agreement between the calculated and experimental results indicates that the proposed deep-biofilm model can be used to estimate the removal efficiency of the readily degradable substrate in anaerobic filters if the ratio of voidage to specific surface area is greater than several millimeters. Also, a higher influent substrate concentration gives a higher substrate removal efficiency if the surface loading is kept the same.