Simultaneous partial nitritation, anammox, and denitrification process for the treatment of simulated municipal sewage in a single-stage biofilter reactor

Low-concentration methanol effect on the microorganisms, nitrogen removal, and recovery of the completely autotrophic nitrogen removal over nitrite

“…Temperature sys was represented Temperature of this system.). When the low-concentration methanol increased from 0 to 38.0 mg•L À1 in this CANON process, the AOB was suppressed with its average activity reducing from 2.42 mg•L À1 •h À1 to 2.09 mg•L À1 •h À1 (Figure 3 The reason of this phenomenon is that low-concentration methanol as a toxicant could cause the microbial toxication or enzyme deactivation of anammox bacteria, which was named formaldehyde inhibition (Huang et al 2022). As a critical anammox enzyme, a hydroxylamine oxidoreductase might change methanol into intracellular formaldehyde, which cross-linked the peptide chains to damaged enzyme and protein activity.…”

“…Protein and polysaccharide enrichment could be the iontransport channel between the bulk liquid and AnAOB, thereby maintaining the 'lung-like breathing' behaviour and increasing the mass transfer efficiency (Chai et al 2019;Li et al 2021). At the optimum concentrations of these organic matters, AnAOB and denitrification bacteria can coexist in one reactor and enhance the nitrogen-removal ability of the CANON process (Huang et al 2022;Sanjaya et al 2022). However, in the presence of excessive organic matter, heterotrophic denitrifiers overgrow and compete with AnAOB for NO 2 À -N, resulting in the elimination of AnAOB (Liu et al 2021), and therefore, elimination of the CANON process.…”

Removal of Steroid Estrogens and Total Nitrogen by Denitrification Biofilter with UV/Peracetic Acid Pretreatment: Performance, Microbial Characteristics, and Mechanism

“…22 The DNBFs were operated in a downflow mode, and the hydraulic retention time (HRT) was set at 8, 5, and 3 h, respectively, concerning the existing research. 23,24 The DNBFs were first inoculated with activated sludge (3800 mg/L MLSS) collected from an anoxic tank at a municipal wastewater treatment plant in Nanjing, China, for 24 h. Then, the synthetic wastewater was directly pumped into the DNBF for W, while it was pretreated by UV/PAA for G. Synthetic wastewater with a C/N of 2 (COD and NO 3 − −N of 50 and 25 mg/L, respectively) was employed, with the components of wastewater shown in Table S1 in the Supporting Information (SI), referring to the previous studies 24,25 and the concentration of the actual tailwater from a wastewater treatment plant in Nanjing, Jiangsu province (China). E1 (purity >99%), E2 (>99%), and E3 (>99%) were purchased from Aladdin, Shanghai, China.…”

Exploring denitrification and anammox processes in the saturated zone of passively operated vegetated biofiltration systems

“…3,4 Extensive work has been done to study bioreactors and unvegetated biofiltration systems that could utilise different nitrogen removal processes, e.g., nitrification, denitrification and anammox (anaerobic ammonium oxidation), to provide satisfactory performance. [5][6][7] However, they usually run on a continuous basis, which often require active operation (e.g., pumps) and thus are not preferable as a decentralised approach. This presents significant opportunities for the application of multi-functional sustainable systems, such as nature-based solutions (NBS), to enhance the treatment of partially treated wastewater (with high nitrogen content 8 ) after onsite wastewater treatment systems (OWTS).…”