Processes and Modelling of Nitrification Denitrification Biological Excess Phosphorus Removal Systems – A Review

Abstract

This paper reviews developments in modelling the kinetics of activated sludge systems: Completely aerobic nitrification, anoxic/aerobic nitrification denitrification (ND), and anaerobic/anoxic/aerobic nitrification denitrification biological excess phosphorus removal (NDBEPR) systems. The paper highlights the progress in developing a general NDBEPR activated sludge kinetic model – development of polyP organism enhanced cultures, their kinetics, simplification of the kinetics for enhanced cultures under constant flow and load conditions, extension of the simplified model to mixed culture NDBEPR systems under constant flow and load conditions, integration of the polyP organism enhanced culture kinetics with the ND kinetics to give a general NDBEPR kinetic model for cyclic flow and load which incorporates the increased specific denitrification rates observed in NDBEPR systems compared to ND systems. Areas of research that require attention to complete the development of the general NDBEPR kinetic model are identified – denitrification by polyP organisms, calibration and verification of the model for cyclic flow and load, etc.

Endogenous model state and parameter estimation from an extensive batch experiment

“…In recent years an increasing interest in the modeling of the endogenous subprocess, in particular for activated sludge processes, has been developed (Beeftink et al, 1990;Dold et al, 1980;Droste, 1996;Horn and Hempel 1997;Janning et al, 1997;Keesman et al, 1998;Pirt, 1965;Ratsak et al, 1996;Spanjers, 1993;Sykes, 1991;Torrijos et al, 1994;Wentzel et al, 1992;Yuan and Stenstrom, 1996). In microbiological literature endogenous respiration is defined in terms of maintenance: it occurs when there is no observed substrate consumption and when maintenance ATP is obtained from biomass degradation.…”

Consideraciones de diseño para la eliminación biológica de fósforo empleando procesos biopelícula

“…Afirman que el Kc no se ajusta muy bien para tiempos de duración de fase anaerobia mayores de 4 horas. Wentzel et al (1992) desarrollan el primer modelo diná-mico en el que se incluye la simulación de eliminación biológica de fósforo, basado en los modelos bioquímicos y cinéticos. En el modelo general se incluyen 25 fenómenos, donde se describe el comportamiento de los heterótrofos, autótrofos y BAFs.…”

“…Debido a la falta de datos experimentales, queda pendiente la evaluación del modelo frente a distintas cargas orgánicas y flujos cíclicos. Henze et al (1995) Wentzel et al ( 1992). El modelo emplea la misma notación matricial descrita en el ASM1.…”

Effect of influent flow rate distribution on the performance of step-feed biological nitrogen removal process

“…Most of the plants recently employ biological process. Various biological nutrient removal processes such as pre-denitrification process (A/O), anaerobic/anoxic/aerobic process (A2/O), University of Cape Town (UCT), modified Bardenpho processes and Virginia Initiative Plant (VIP) were developed and widely applied [1][2][3][4][5][6]. These approaches will require additional energy for liquid circulation and addition of external carbon substrate for denitrification in anoxic zones.…”