Anammox bacteria with attached-growth media for nitrogen removal in wastewater

Partial nitrification/ANAMMOX (PN/A) membrane aerated biofilm reactor (MABR) under a low C/N ratio and metagenomics identification

“…This may be because P g (1-2 kPa) reduced the activity of common Environmental Science: Water Research & Technology Paper heterotrophs and the thickness of the biofilm, 38 improved the mass transfer efficiency and ensured the partial nitrification process. 10,37 In addition, it was also verified that a partial nitrification MABR can entrap ANAMMOX bacteria and realize a PN/A MABR. 9 This study has proved that the PN/A MABR can effectively remove nitrogen under a low C/N ratio, but the operating parameters were extremely stringent.…”

“…A high DO suppresses the activity of anaerobic bacteria, including ANAMMOX bacteria and DB. 10 Hence, the weakening of the denitrification and ANAMMOX processes affected the TNRE.…”

“…[5][6][7] The substrates diffuse from the wastewater to the biofilm, and oxygen diffuses from the hollow membrane to the biofilm, forming a counter-diffusion phenomenon in the MABR, which can improve the nitrogen removal efficiency. [8][9][10] In the recent 20 years, the ANAMMOX process as the most economical and efficient nitrogen removal process has been widely studied. It can use nitrite to oxidize ammonium directly into dinitrogen gas without organics and aeration.…”

“…11,12 This process can contribute to low-carbon emissions for WWTPs. 10 However, mainstream PN/A is rarely successfully applied in engineering. 13 Nitrite accumulation 14,15 and ANAMMOX bacteria enrichment and retention 16 are the pivotal technical bottlenecks.…”

“…5–7 The substrates diffuse from the wastewater to the biofilm, and oxygen diffuses from the hollow membrane to the biofilm, forming a counter-diffusion phenomenon in the MABR, which can improve the nitrogen removal efficiency. 8–10…”