Comparative Evaluation of Sequencing Batch Reactors

The performance of many processes and operations can be improved appreciably by the controlled unsteady operations that are provided by sequencing batch (fill and draw) biological reactors. The lack of design and operation experience in batch treatment has resulted in an experience void that has fostered the selection of continuous flow rather than batch treatment schemes. System selection should depend instead upon suitability of the system, reliability, efficiency, consistency, and economics. Bench, pilot, and full-scale investigations, and desk top and computer analyses must supplement existing bench scale studies if the experience void is to be filled. Several hypothetical examples are used to partially fill the void by comparing volumes for both the batch and continuous flow system. In the examples, sequencing batch treatment provides the potential for achieving effluent limitations in a total volume notably less than that for a conventional continuous flow system. This adds to previously recognized advantages that include holding a waste until proper treatment is achieved.