Shock Load Attenuation by a Trickling Filter

The property of shock load attenuation by a trickling filter appears to be a result of harboring bacteria at the lower depths of the filter under starvation conditions. When a shock load is applied to the filter, the bacteria respond in the same manner as do those bacteria in the biosorption process. They have considerable reserve capacity for substrate assimilation. A model trickling filter was operated in the laboratory at various organic loadings. The organic assimilation capacity of the filter was determined and various depths (boxes) of the filter were interchanged to ascertain their respective organic assimilation capacities at their new depth location in the filter. In order to exhibit shock loading attenuation properties, the filter must be somewhat oversized and be allowed to operate having the bulk of organic removal occurring in the upper few feet of the filter. This maintains a viable population of bacteria in the lower depths under starvation conditions that provide the shock load attenuation capability.