The overall objective of this research was to investigate various methods and parameters to increase the efficiency of chemically enhanced primary treatment (CEPT). The performance of CEPT was evaluated based on its efficiency of removal of nonsettleable solids (NSS). Some of the source characteristics that influenced NSS concentration included influent total suspended solids, influent turbidity, and influent total chemical oxygen demand. A higher concentration of the influent constituents led to a higher NSS concentration, suggesting that NSS represented a somewhat fixed fraction or percent of these influent constituents. The specific particle surface area (SPSA) was found to correlate with percent NSS in the effluent. A higher SPSA is a result of smaller-sized nonsettleable colloidal particles, thus leading to an increase in percent NSS. In summary, there are several parameters that affect NSS, which could be used to control NSS to improve CEPT, as demonstrated by this study. Water Environ. Res., 80, 331 (2008).

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The Moving Bed Biofilm Reactor (MBBR) technology was determined to be a promising and viable process for denitrification to achieve total nitrogen of between 3-4 mg N/L and nitrate concentration below 1 mg N/L. A post-denitrifying pilot MBBR system was set up at the Blue Plains AWTP (Advanced Wastewater Treatment Plant) and a bench scale kinetic evaluation was conducted. This study is a compilation of the ex-situ bench evaluations of the media grown in the pilot reactor. Denitrification kinetics and stoichiometry of MBBR technology using methanol as an external carbon source were investigated. The average specific denitrification rates (SDNR) were determined between 1.3 -2.0 g NO x -N/m 2 -day, and the stoichiometric C:N ratios were 4.6 -5.8 mg COD/mg NO x -N for a temperature range of 13 -18 o C. Experimental values were used to obtain Ks NOx-N (effective NO x -N half saturation constant) for different temperatures using a model developed based on the Monod kinetic expression and a spreadsheet interactive search routine. Values of effective Ks NOx-N were observed between 0.6 and 1.1 mg N/L for experimental temperatures ranging from 12.5 to 20 o C.