Tertiary Denitrifying MBBRs: The Right Choice?

After reviewing the data from two pilot studies and a full-scale operating plant, it is clear that Moving Bed Biofilm Reactors (MBBRs) are reliable and robust alternative for tertiary denitrification; however, other factors outside the MBBR process play a significant role in determining whether or not it is the right choice for implementing this technology. The 2.3 mgd South Caboolture Plant near Brisbane, Australia has been successfully operating an MBBR plant for close to 10 years. The Noman M. Cole Jr. Pollution Control Plant (NCPCP) selected the MBBR technology for their ENR program after a successful pilot study and are in the final design stages. The Blue Plains Advanced Wastewater Treatment Plant (AWTF), however, did not select the MBBR technology even after a successful pilot. This paper compares and contrasts these studies by: 1) Evaluating each of these cases; 2) Presenting the design and operating data from each; 3) Discussing the key findings of each; and 4) Discussing what factors generally lead to the selection or non-selection of MBBRs for tertiary denitrification. The key factors include the NOx-N loadings, influent phosphorous concentrations, solids production, and downstream solids removal processes.