Hydraulic Age Distribution in Perfectly Mixed Non Steady

Juanico M. and Friedler E. (1994)
Hydraulic age distribution in perfectly mixed non steady-state reactors.
ASCE J. of Environ. Eng., 120(6): 1427-1445.

ABSTRACT

The Leslie Matrix Model is applied to the analysis of the hydraulic age distribution of perfectly mixed, non steady-state flow reactors. The relationship between the hydraulic age distribution and the performance of this kind of reactors is discussed, and the concepts and algorithms developed in the paper are applied to a case study. Steady-state flow and batch reactors are particular cases of the non steady-state flow reactor. The percentage of fresh effluents within the reactor (PFE) is a better descriptor of the reactor performance than the Mean Residence Time. When a reactor is under strict steady-state flow conditions, the ratio PFE/mean residence time is constant, and only then PFE can be substituted by the mean residence time. High rate reactions (such as Faecal coliforms removal in sewage treatment systems) correlate better with PFE of a few days (1 to 5 days in the discussed example) while low rate reactions (such as BOD removal) correlate better with PFE of more days (30 days in the example). Computer algorithms for the calculation of PFE and the mean residence time are provided.

KEYWORDS
non steady-state flow reactor, sequential batch reactor, mean residence time, hydraulic age distribution, sewage treatment, wastewater treatment