Simultaneous nitrification, denitrification and phosphorus recovery (SNDPr) - An opportunity to facilitate full-scale recovery of phosphorus from municipal wastewater

Abstract

Sewage treatment plants are a potential point source for recycling of phosphorus (P). Several 23 technologies have been proposed to biologically recover P from wastewater. The majority of 24 these technologies are side-stream processes and rely on an external source of soluble organic 25 carbon to facilitate P recovery. To date, no studies have demonstrated the potential to facilitate 26 main-stream recovery of P, using carbon that is naturally present in wastewater. Simultaneous 27 nitrification, denitrification and phosphorus removal (SNDPR) is an elegant process that can 28 uptake influent carbon and effectively remove both nitrogen (N) and P from wastewater. 29SNDPR studies to date, however, have failed to facilitate a P rich liquor end-of-anaerobic-30 phase, that enables economies of scale to recover influent P. Therefore, this study examined 31 the feasibility of achieving a P rich liquor (e.g. > 70 mg-P/L) with granular SNDPR process. A 32 synthetic influent that replicated the nutrient and carbon concentrations of municipal 33 wastewater was used to investigate whether carbon in the influent wastewater could enable 34 both nutrient removal and P recovery from wastewater. Our granular SNDPR process was able 35 to facilitate a P rich liquor of approximately 100 mg-P/L end-of-anaerobic-phase. A dissolved 36 oxygen (DO) concentration of 0.5 mg/L in a sequencing batch reactor (SBR) was found to be 37 essential to achieve complete nutrient removal and a high P concentration at the end of the 38 anaerobic phase. At this steady state of reactor operation, the abundance of polyphosphate 39 accumulating organisms (PAOs) was 2.6 times the abundance of glycogen accumulating 40 organisms (GAOs). The study also demonstrated the importance of denitrifying polyphosphate 41 accumulating organisms (DPAOs) and glycogen accumulating organisms (DGAOs) to achieve 42 complete removal of N from the effluent. Compared to nitrifying bacteria, the polyphosphate 43accumulating organisms (PAOs) had a higher affinity towards DO. This study, for the first 44 time, showed that the mainstream recovery of P is feasible using a SNDPR process.

Pollutant removal from municipal sewage by a microaerobic up-flow oxidation ditch coupled with micro-electrolysis

“…In response to long-term operation under microaerobic conditions, the proportions of Chloroflexi, Acidobacteria, Gemmatimonadetes and Planctomycetes in S1–3 increased dramatically in comparison to those in S0, but there was a decrease in the proportions of Proteobacteria, Bacteroidetes, Patescibacteria, Nitrospirae and Firmicutes. Moreover, Proteobacteria, Chloroflexi and Bacteroidetes were dominant phyla in all samples, which were in accordance with previous studies [ 8 , 10 , 12 , 13 , 16 , 17 , 30 ]. These phyla play important roles in carbon and nitrogen metabolism.…”

“…In addition, the extra carbon sources required for heterotrophic denitrification cause substantial excess sludge production [7]. To further address the shortcomings of those traditional nitrogen removal methods, new principles and strategies have been proposed, such as partial nitrification-denitrification [8][9][10][11], anaerobic ammonium oxidation (anammox) [12][13][14], and simultaneous nitrification and denitrification (SND) [15][16][17]. These approaches are based on the fact that ammonium-oxidizing bacteria (AOB) convert ammonium into an intermediary compound, nitrite, which is then transformed to nitrogen gas by autotrophic denitrification, heterotrophic denitrification and anammox [18,19].…”

Nitrification in the presence of sulfide and organic matter in a sequencing moving bed biofilm reactor (SMBBR) with zeolite as biomass carrier

“…After that, the VSS concentration decreased strongly down to 0.78 g L −1 (Day 14), a value very close to the initial VSS concentration at this NLR. However, the biomass keep its concentration (measured as VSS) in a stationary range that can be attributed to the high‐volume exchange ratio (75%) and the high SRT (49 d) maintained, a situation also obtained by Salehi et al Although both systems (with and without zeolite) had an increase and decrease of VSS concentration, the TAN oxidation and nitrite oxidation were not affected, as shown in Figs (a) and (b). At NLR = 0.176 kgN m −3 d –1 , both systems started at a VSS concentration of ≈1.35 g L −1 .…”

Advances in Studies on Microbiota Involved in Nitrogen Removal Processes and Their Applications in Wastewater Treatment

“…Especially, the simultaneous nitrification-denitrification process requires the simultaneous presence of aerobic and anaerobic environments within the same reactor; hence, the DO concentration directly affects the denitrification rate and efficiency ( Wang et al, 2018 ). Moreover, the SND process had been applied for the removal of phosphorus pollutants from municipal wastewater, showing the SND process is feasible in phosphorus removal ( Salehi et al, 2019 ).…”