Operation performance and microbial community dynamics of phosphorus removal sludge with different electron acceptors

Abstract

Operation performances of phosphorus removal sludge with different electron acceptors in three parallel SBRs were firstly compared in the present study, and the effect of post-aeration on denitrifying phosphorus removal was also studied. Moreover, community dynamics of different phosphorus removal sludge was systematically investigated with high-throughput sequencing for the first time. TP removal rates for nitrate-, nitrite-, and oxygen-based phosphorus removal sludge were 84.8, 78.5, and 87.4 %, with an average effluent TP concentration of 0.758, 0.931, and 0.632 mg/l. The average specific phosphorus release and uptake rates were 20.3, 10.8, and 21.5, and 9.43, 8.68, and 10.8 mgP/(gVSS h), respectively. Moreover, electron utilization efficiency of denitrifying phosphorus removal sludge with nitrate as electron acceptor was higher than nitrite, with P/e(-) were 2.21 and 1.51 mol-P/mol-e(-), respectively. With the assistance of post-aeration for nitrate-based denitrifying phosphorus removal sludge, settling ability could be improved, with SVI decreased from 120 to 80 and 72 ml/g when post-aeration time was 0, 10, and 30 min, respectively. Moreover, further phosphorus removal could be achieved during post-aeration with increased aeration time. However, the anoxic phosphorus uptake was deteriorated, which was likely a result of shifted microbial community structure. Post-aeration of approximately 10 min was proposed for denitrifying phosphorus removal. Nitrate- and nitrite-based denitrifying phosphorus removal sludge exhibited similar community structure. More phosphorus accumulating organisms were enriched under anaerobic-aerobic conditions, while anaerobic-anoxic conditions were favorable for suppressing glycogen-accumulating organisms. Significant differences in pathogenic bacterial community profiles revealed in the current study indicated the potential public health hazards of non-aeration activated sludge system.

Comparison of bacterial communities in channel catfish Ictalurus punctatus culture ponds of an industrial ecological purification recirculating aquaculture system

“…The phylum Proteobacteria is a highly diverse phenotypic and phylogenetic lineage (Kersters et al, 2006) (Hahn, 2003). The sand filter pond had abundant species belonging to the genus Dechloromonas (accounting for 11.50% ± 0.02), which was absent in the other samples, and several studies have identified members of this genus as denitrifying polyphosphate-accumulating organisms (DPAOs) Dai, Wu, et al, 2017;Lv et al, 2014). Moreover, members of the genus Synechococcus have been reported to remove nutrients (total nitrogen and total phosphorus) from wastewater (Deng, Gao, & Sun, 2012).…”

Functional guild dynamics in a single-sludge shortcut nitrogen and phosphorus removal reactor: a modeling study

“…DPAO can be readily selected in a sequencing batch reactor (SBR) operated in anaerobic/anoxic mode by dosing nitrate or nitrite during the anoxic phase. 15,16 Tsuneda et al 17 used anaerobic-oxic-anoxic (AOA) operation mode to select DPAO by dosing supplemental carbon at the beginning of the oxic phase in order to encourage oxygen use by heterotrophic bacteria so as to provide competition for this electron acceptor to polyphosphate accumulating organisms (PAO); they then measured anoxic phosphate uptake rate and aerobic phosphate uptake rate. For comparison, they also measured the ratio of anoxic phosphate uptake rate to aerobic phosphate uptake rate of biomass taken directly from a wastewater treatment plant applying an anaerobic-anoxicoxic (AAO) process, and from a lab-scale SBR operating in anaerobic-oxic mode.…”