Optimization of Nitrogen Removal for Alternating Intermittent Aeration-Type Activated Sludge System: A New Process Modification

Abstract

A new activated sludge process modification was proposed for intermittent aeration process to achieve more stable nitrogen removal performance. A single completely mixed reactor was divided into two compartments in series and operated in intermittent aeration mode by using activated sludge simulation model. The new configuration provided competetive advantage on nitrification as well as denitrification capacity, compared to the intermittently aerated system with a single reactor. In addition, the dissolved oxygen set-point control during air-on periods was found to be an important parameter in terms of nitrogen removal.

Model Based Optimization of Nitrogen Removal in a Full Scale Activated Sludge Plant

“…These are minimum aerobic sludge age was maintained as discussed above and the system was operated under low DO by providing 76% of total oxygen requirement of the system. As a result, 75%-80% nitrogen removal was achieved due to simultaneous nitrification and denitrification process (SNdN) under low DO levels (Münch et al, 1993;Insel et al, 2006b;Insel, 2007) …”

“…This was secured by an intermittent aeration strategy implemented in the simulation layout as shown in Figure 2. Intermittent aeration is a well-known activated sludge configuration for efficient nitrogen removal (Lin and Tsang, 1997;Hanhan et al, 2002;Insel et al, 2006b). Shortly, this strategy relies upon two specific parameters, namely the aerated fraction (AF) and cycle time ratio (CTR).…”

“…For full-scale models, dissolved oxygen and therefore aeration, play a vital role on system performance, especially on the extent of nitrification and simultaneous nitrification/denitrification processes taking place in biologic reactors. Recently, modeling studies have focused on evaluating the impact of aeration on the performance of different systems (Insel et al, 2006a(Insel et al, , 2006bInsel, 2007).…”

A Novel Method to Determine Blower Capacity of Wastewater Treatment Plants for Dry and Wet Weather Conditions

“…As listed in Table 2, the virtual WWTP was modelled to receive the influent at 36,000 m 3 /d of constant flow rate with the hourly discretised concentrations which were collected from the analysis of Site #1, Site #2 and Site #3 respectively. The virtual WWTP had a big blower controlled by a DO sensor allowing to manipulate the blower power in a dynamic manner to maintain 1 mg-O 2 /L of DO in the aeration tank [30,31]. In this way, the highest aeration (peak power consumption of the blower) lasting for one hour was identified in each day.…”