Achieving mainstream anammox in biological aerated filter by regulating bacteria community structure.

Although mainstream partial nitrification-anammox (PN-A) is a highly efficient and sustainable wastewater treatment process, it is difficult to achieve and stabilize due to the competition among functional bacteria. In this study, achieving one-stage mainstream anammox via regulating bacteria community structure was studied in a lab-scale biological aerated filter (BAF). The results showed that high free ammonia with 89.

NO production and emission pathways in anammox biofilter for treating wastewater with low nitrogen concentrations.

Although anaerobic ammonia oxidation (anammox) is a cost-effective nitrogen removal process, nitrous oxide (NO) production will greatly reduce the advantages of this process. It is important to identify the NO emission pathways and then reduce the NO production in anammox system. To date, very limited research has been done to investigate the NO production and NO emission pathways in anammox biofilter.

Achieving partial denitrification-anammox in biofilter for advanced wastewater treatment.

Recently, partial denitrification (PDN) - anaerobic ammonium oxidation (anammox) process has been widely studied in activated sludge for nitrate wastewater treatment. However, achieving PDN-Anammox in biofilter for domestic wastewater treatment was never reported. In this study, two lab-scale PDN biofilter and Anammox biofilter were built up to treat simulated domestic wastewater.

[Effect of Free Nitrous Acid on the Activity of Nitrifying Bacteria in Different Sludge Concentrations Under Anoxic Conditions].

This study investigated the inhibitory effect of free nitrous acid (FNA) on the activity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under anoxic conditions with different mixed liquid suspended solids (MLSS). Sequencing batch reactors were used to study the changes in the activity of AOB and NOB in nitrifying activated sludge based on four different MLSS (8398, 11254, 15998, and 19637 mg·L), after treatment, under anoxic conditions with FNA (at an initial concentration of 1.3 mg·L) for 48 h.

Initial nitrite concentration promote nitrite-oxidizing bacteria activity recovery from transient anoxia: Experimental and modeling investigations.

Transient anoxia due to the periodic anoxic/aerobic operation is beneficial for the nitrite-oxidizing bacteria (NOB) suppression. A continuous reactor of modified University of Cape Town process treating municipal wastewater was equipped with alternating anoxic/aerobic zones to maintain nitritation. Higher nitrite accumulation ratio in the oxic zones was achieved through transient anoxia and shorter aerobic actual hydraulic retention time (15 min), but it steeply deteriorated from above 95.