Electronic Theses and Dissertations




Parsa Pezeshk



Document Type

Dissertation (Campus Access Only)

Degree Name

Doctor of Philosophy




Civil Engineering

Committee Chair

Charles Camp

Committee Member

Stephanie Ivey

Committee Member

Larry Moore

Committee Member

Dale Armstrong


Activated Sludge Model 1 (ASM1) is a set of 13 ordinary differential equations that can be used to simulate the performance of an activated sludge treatment system in terms of carbon and nitrogen removal. The purpose of this research is to calibrate the kinetic parameters of ASM1 for biological treatment in an oxidation ditch activated sludge system using a Big Bang-Big Crunch optimization algorithm. Completely stirred tank reactors (CSTRs) in series are used to model the hydraulics of the ditch. The results show that 17 CSTRs in series could be used to model the hydraulics of the ditch. Since wastewater circulation velocity in the ditch affects wastewater detention times, it was directly measured in the field as a function of number of surface aerators in operation. A queueing mechanism was devised to model detention times for CSTRs in series during dynamic simulation. Influent wastewater was characterized based on plant data and typical characterization fractions reported in the literature. Newton-Raphson method is used to reduce the computational time to find steady state solutions. An integration step size of 25 seconds is shown to be satisfactory for dynamic simulation. Finally, ASM1 kinetic parameters are selected to minimize the difference between simulated and observed values for TSS, BOD5, NH3-N, and suspended solids in the ditch effluent.


Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.