KINETIC-ANALYSIS OF ALTERNATIVE CONFIGURATIONS FOR SINGLE-SLUDGE NITRIFICATION DENITRIFICATION

Single-sludge wastewater treatment systems for biological nitrification/denitrification offer significant advantages over multiple sludge systems. However, design and control of single-sludge systems is difficult because of interactions among the competing microbiological processes. A computer simulation model was developed to aid in the analysis of single-sludge systems. Results of applying this model to the intermittently aerated completely mixed configuration are presented. These simulations identified the importance of two new process variables - the aeration fraction and the cycle time ratio. A simplified kinetic model was then used to investigate the importance of these variables to other single-sludge configurations. It was found that under conditions of small cycle time ratios, all configurations performed the same. Hence, results of computer simulation of the intermittently aerated completely mixed configuration can be applied to other systems. Furthermore, a single procedure can be used to design any configuration. Such a procedure is presented.

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