Effects Of Primary Effluent Filtration On Trickling Filter Design And Operation

The BOD associated with the suspended solids in effluents from primary clarifiers represents a substantial portion of the organic load applied to subsequent wastewater treatment processes. Recently, specially designed filters have been developed to deal with the problems associated with the filtration of primary effluent. An example of these filters is a fine-grained, shallow-bed, air-pulsed filter. This filter has been applied successfully to treat primary effluents at a number of locations. Average suspended solids and BOD5 removals have been reported to be 50 to 70% and 25 to 45%, respectively. The purpose of this paper is to present information on how the use of primary effluent filtration may alter the design and operating characteristics of trickling filters, and to present a methodology which may be used to estimate the effects of primary effluent filtration on trickling filter performance.