Impact of multiple wastewater feedings on the efficiency of nutrient removal in an IFAS-MBSBBR: number of feedings vs. efficiency of nutrient removal

Abstract

This article presents the results of research into the influence of one, two and three wastewater feedings in a cycle on efficiency and performance of combined biological nitrogen and phosphorus removal in an integrated fixed-film activated sludge and moving-bed sequencing batch biofilm reactor (IFAS-MBSBBR). The experiment lasted 158 days and was conducted in two laboratory models of the IFAS-MBSBBR with an active volume of 28 L. It was found that along with an increase in the number of wastewater feedings, an increase in nitrogen removal efficiency was observed (from 56.9 ± 2.30% for a single feeding to 91.4 ± 1.77% for three feedings). Moreover, the contribution of simultaneous nitrification/denitrification in nitrogen removal increased (from 2.58% for a single feeding to 69.5% for three feedings). Systems with a greater number of feedings stimulated the process of denitrifying phosphorus removal. Regardless of the way in which wastewater feeding was applied to the IFAS-MBSBBR, highly efficient chemical oxygen demand (COD) removal (94.8 ± 1.80%) and biological phosphorus removal (98.9 ± 0.87%) were achieved.

Effect of anaerobic phases length on denitrifying dephosphatation biocenosis – a case study of IFAS-MBSBBR

“…The highest efficiency of the denitrification process (91.1 ± 1.8%) was achieved in series A3, probably due to the introduction of multiple feeding, which allows for better use of the organic compounds by the biomass present in the reactor. Our previous studies [ 15 ] have shown that the number of feedings in the cycle has a significant impact on the effectiveness of the denitrification process in the IFAS-MBSBBR system.…”

“…Due to the similar physiology of PAO and GAO (organic substance uptake in anaerobic conditions, ability to respire in the presence of nitrate or nitrite), the overlap of ecological niches of the two groups is high, and therefore there should be a tendency for ruling out one of the two groups. The two groups coexist in most of the full scale enhanced biological phosphorus removal plants [ 22 , 23 ] and laboratory systems [ 10 , 15 ]. They are also found together in systems focused on denitrifying dephosphatation [ 15 ] and in the system presented in the study.…”

“…The two groups coexist in most of the full scale enhanced biological phosphorus removal plants [ 22 , 23 ] and laboratory systems [ 10 , 15 ]. They are also found together in systems focused on denitrifying dephosphatation [ 15 ] and in the system presented in the study.…”

“…The reactor was operated in an air-conditioned room (temperature 18 °C). A detailed description of IFAS-MBSBBR can be found at Podedworna et al [ 15 ].…”

“…Denitrifying dephosphatation can also be achieved in the sequencing batch reactors. The examples of such solution are: SBR (Sequencing Batch Reactor) [ 11 ] with activated sludge, SBBR (Sequencing Batch Biofilm Reactor, [ 12 ], or pure MBSBBR (Moving Bed Sequencing Batch Biofilm Reactor)) [ 13 , 14 ], in which biomass was developed mostly in a biofilm formed on the surface of moving carriers, and IFAS-MBSBBR (Integrated Fixed-Film Activated Sludge – Moving-Bed Sequencing Batch Biofilm Reactor) [ 15 ], in which biomass was developed as activated sludge and biofilm. In the case of IFAS-MBSBBR, after the anaerobic phase that ensures the removal of readily biodegradable organic compounds, an aerobic phase occurs, where the oxidation of ammonia is held.…”