Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Civil and Environmental Engineering

First Advisor

Marty E. Tittlebaum


Microbial Rock Plant Filters (MRPFs) are capable of treating municipal wastewaters, particularly for the removal of biochemical oxygen demand (BOD) in an economic manner. There is no consensus on proper design for these treatment systems due to the limited performance data available on these recently developed systems (Reed, 1993). Variability of the BOD removal reaction rate constant is an important observation which has bearing on the design of these systems. Variability of BOD removal reaction rate constant along the filter length was modeled as a function of the variable microbial activity. The microbial activity was estimated using a modified fluorescein diacetate (FDA) method. Variability of dissolved oxygen (DO), hydrogen ion concentration (pH), temperature, and ammonia nitrogen (NH$\sb3$-N) in the wastewater along the filter length was also monitored. The study included monitoring of the MRPF located at Benton, Louisiana. A modified design criteria for MRPF treatment systems based on the modeled BOD removal reaction rate constant is suggested. It is expected that the use of this method will optimize the filter size for any given waste quantity and characteristics and ensures proper design.