Optimizing nitrogen removal in the BioDenitro process

Abstract

The potential and limits of different configurations of the BioDenitro-alternating process to suit the various design cases that can arise depending on the wastewater characteristics, space necessary and effluent nitrogen requirements were analysed through simulations of the activated sludge model No. 2. The first analysis involved the combination in one cycle of the main phase in the alternating reactors with an aerated phase having the two reactors in aerobic conditions and/or a hydraulic phase using the flow only in the anoxic reactor. This option has been found to have a very high potential for cases with strict requirements concerning effluent total nitrogen, but limited when the requirements are low effluent NH4-N, relatively high effluent total nitrogen and minimum solids and hydraulic retention times. When the latter conditions have to be fulfilled the incorporation of a post-aeration reactor to the alternating reactor was found to be very effective. In addition the configuration is very flexible because multiple combinations of post-aeration reactor volumes and in the duration of the different phases in the alternating reactors can be selected to achieve effluent nitrogen requirements. This flexibility is limited to the use of moderate values in the post-aeration reactor volumes and in the duration of the aerated phase. An experimental trial of the latter configuration was carried out and demonstrated its operational simplicity by achieving the desired nitrogen requirements in the effluent simply by changing the duration of the aerated phase for a given post-aeration reactor volume. From the experimental results an enhanced simultaneous nitrification-denitrification at the start of aeration in the alternating reactors was found and the ASM2 model was shown to have a satisfactory predictive capacity.

Mathematical Modelling and Computer Simulation of Activated Sludge Systems

“…Adjustment of the phase lengths in alternating aeration and flow processes • (Dupont and Sinkjaer 1994;Potter et al 1996;Irizar et al 2003;Fikar et al 2005); DO control in the aerated zones (Leeuw • et al 1996;Solley and Barr 1999); Addition of the readily biodegradable substrate, such as fermentation • products of the raw sludge from primary clarifiers (Funamizu et al 1997); Shutting down one treatment line and overloading the other lines (Carucci • et al 1999); Reduction of the total nitrogen emission during stormwater events • (Seggelke andRosenwinkel 2002, Rosenwinkel et al 2007b;Ahnert et al 2009); Adjustment of the cycle range and the ratio between the nitrification and • denitrification length in an intermittently aerated process (Andreottola et al 2003); Adjustment of the mixed liquor recirculation between the nitrification • and denitrification compartments (Moussa et al 2004); Dosing ammonia rich substrate to the regeneration zone of the R-D-N • process (Novak and Havrlikova 2004); Adjustment of production schedules in a chemical industry WWTP (van • Hulle and Vanrolleghem 2004); Analysis of possible modifications in the layout of an oil refinery WWTP • and reduction of operating costs (Pardo et al 2007); Strategy of dosing external source to enhance denitrification (Phillips • et al 2009). …”

Effect of cycle length and phase fraction on biological nutrients removal in temporal and spatial phase separated process

“…In recent years, phased isolation technology, such as a BioDenitro and a BioDenipho, has also been applied extensively [6][7][8]. The phased isolation technologies have various advantages when compared to SBR including high stability achieved by maintaining continuous flow, regular water level, and minimal complexity through the elimination of the decanter and its associated equipments [9].…”

“…The literature on the phased isolation processes have also primarily emphasized only nitrogen removal [7,[11][12][13]. Thus, we have conducted the present research in order to clarify the optimal cycle length and evaluate the effect of the fraction of anoxic and anaerobic phases in a cycle time which maximizes the simultaneous removal of nitrogen and phosphorus without external carbon sources in a modified temporal and spatial phase isolated process.…”

Application of tube-type ceramic microfiltration membrane for post-treatment of effluent from biological wastewater treatment process using phase separation

“…Numerous studies on the biological nutrient removal (BNR) process have been carried out. Most notably, phase separation technology adopting intermittent aeration and flow path change has been widely used and applied [7][8][9][10]. This technology has some advantages: (1) elimination of the need for internal recirculation of sludge and nitrified effluent, (2) higher process flexibility by controlling each phase to match the fluctuation of influent loads, and so on.…”