The effect of an anoxic zone on biological phosphorus removal by a sequential batch reactor

Simultaneous nitrogen and phosphorus removal by a novel sequencing batch moving bed membrane bioreactor for wastewater treatment

“…In the anaerobic phase, the residual nitrate and nitrite could be removed by using the influent COD as substrate. Whereas, the transfer of residual nitrate and nitrite into the anaerobic phase could consume a portion of the substrate before the substrate being utilized by PAOs, which might inhibit phosphate release [5][6][7]. Therefore, in order to ensure simultaneous nitrogen and phosphorus removal, the SND performance must be enhanced during aerobic phase.…”

“…The denitrification complicates the EBPR since the denitrifiers consume a portion of the substrate before the substrate can be utilized by the biological phosphorus removing organisms, in other words, the transfer of nitrate into the anaerobic phase inhibits phosphate release [6,7]. In order to resolve this conflict, a number of changes had been introduced in SBR systems, such as filling the SBR with carriers or aerobic granular instead of activated sludge [8].…”

Landfill Leachate Nutrient Removal Using Intermittent Aeration

“…Figure 5 presents the phosphorus concentration profile at successive anoxic/aerobic phases during the experimental set-ups I (Aerobic 3 h/Anoxic1h-24 h), III (Aerobic 3 h/Anoxic3h-48 h) and IV (Aerobic 6 h/Anoxic2h-48 h). It is obvious that 1 h anoxic phase was not enough for phosphate release since PO 4 3− -P concentration remained almost constant after 24 h. Experiments III and IV resulted in phosphorus release during the anoxic phase, while phosphorus uptake was observed in the successive aerobic phase, indicating the system ability of performing enhanced biological phosphorus removal (EBPR) (Guo et al 2011;Akin and Ugurlu 2004). In both experimental conditions, negligible PO 4 3− -P concentrations remained in the effluent at the end of the aerobic phase.…”

“…In both experimental conditions, negligible PO 4 3− -P concentrations remained in the effluent at the end of the aerobic phase. The influence of NO 3 -N concentration on the phosphorus release during the anoxic phase was also examined (Akin and Ugurlu 2004;Kuba et al 1994). Figure 6 presents the detailed profiles of PO 4 3− -P and NO 3 − -N concentrations and pH during the experimental set-ups I, III and IV.…”

Effect of substrate N/COD ratio on the formation and characteristics of aerobic granules developed in sequencing batch reactors

“…As compared to conventional activated sludge systems, the SBR systems have many advantages including reduced operational costs, improved nitrogen and phosphorus removal, and less bulking (Akin and Ugurlu, 2004). Previous research showed that the removal efficiencies of organic carbon and nitrogen in SBR were strongly related to solids retention time, cycle time, hydraulic retention time and phase-length distribution (Chang and Hao, 1996;Colunga and Martines, 1996;Andreottola et al, 1997;Umble and Ketchum 1997;Chang et al, 2000;Uygur 2002,2004).…”