E-Andrew Sindt Creative Component S11.pdf

Percent removalsettings. The cause for this significant variation between the phosphorus effluent concentrations fordefault values and calibrated values was identified. Total nitrogen removal for both settings increasesas anoxic period length increases. This appears to be a function of denitrification, similar to theanaerobic-oxic plot.100959085807570Default TNDefault TPCal. TNCal. TP65600 50 100 150Anoxic period length (min)Figure 4.21 - Percent removal plot for BNR-S1 mode for oxic-anoxic period length variations. Dashedline signifies default period length (90min). Oxic period length (min)= 180 (min) - anoxic period length(min)4.6.3 Phase Variation SummaryIn both analysis the percent removal of TP and TN were maximized when the oxic period length wasminimized. Therefore, the cycle which contained the lowest fraction of oxic phase provided the bestpercent removals. Increasing the anaerobic phase length resulted in great TP removal for the calibratedmodel. Therefore, the optimum anaerobic/anoxic/oxic cycle sequence was 140/90/40 minutes.67