Mainstream partial nitritation was studied at 10° C. in a moving bed biofilm reactor treating synthetic wastewater containing both nitrogen (≈40 mg L-1) and organic carbon at COD/N ratio ranging from 1.3 to 2.2. Three different control strategies were investigated to achieve partial nitritation. Initially, biofilm age was controlled by incorporating a media replacement strategy. Next, separately from the media replacement, oxygen limited conditions were investigated and finally pH control was incorporated together with oxygen limitation. Successful partial nitritation was achieved only by combining oxygen limitation with pH control. The average NH4-N concentration was equal to 16.0±1.6 mg L-1 and average NO2-N concentration was equal to 15.7±2.4 mg L-1 during steady state partial nitritation. The average residual NO3-N concentration was equal to 2.6±2.2 mg L-1. The results obtained from this study prove for the first time that partial nitritation can be successfully controlled in a biofilm reactor treating wastewater with low nitrogen concentration, relatively high COD/N ratio and at low temperature. An algorithm for dynamic process control of partial nitritation has been also developed.

A device and method for treating urban domestic sewage based on a two-stage combined process of partial denitrification-anammox belong to the field of biological sewage treatment. The device includes a raw water tank, a sequencing batch biofilm reactor (SBBR), an intermediate water tank, an up-flow anaerobic sludge bed (UASB) and a water outlet tank. A part of urban domestic sewage enters the SBBR and is mixed with residual sewage in the last cycle, a partial denitrification-anammox reaction is carried out under a stirring condition to remove nitrate nitrogen and a part of ammonia nitrogen, followed by a nitrification under an aeration condition to completely convert ammonia nitrogen into nitrate nitrogen, and effluent enters the intermediate water tank; and the other part of the urban domestic sewage is mixed with the effluent of the SBBR and continuously enters the UASB, and nitrite nitrogen, which is generated by nitrate nitrogen reduction, and ammonia nitrogen, are removed by means of anammox. According to the present invention, with no need of adding an external carbon source, organic matters in sewage can be effectively removed, the nitrogen removal efficiency of urban domestic sewage is improved, and efficient and low-consumption nitrogen removal is realized.

The present invention discloses a method for starting a single-stage system for nitrogen removal coupling partial denitrification and anammox. The two nitrogen removal processes are coupled by gradually enriching denitrifying bacteria in anammox granular sludge and then activating the partial denitrification process of the functional bacteria (denitrifying bacteria). Particularly, the method comprises: inoculating anammox granular sludge in a single-stage reactor, adding an organic carbon source in gradients to enrich denitrifying bacteria and to adapt anammox bacteria, and replacing nitrites in feed with nitrates gradually to activate the partial denitrification process.

This specification describes a membrane aerated biofilm reactor (MABR) and processes for nitritation, nitritation-denitritation or deammonification. The supply of oxygen through the gas-transfer membrane is limited to suppress the growth of nitrite oxidizing bacteria (NOB). Exhaust gas from an MABR unit may have an oxygen concentration of 4% or less. The process can optionally include one or more of: intermittent (batch) feed of process air; process air modulation; process air direction reversal; process air recycle; and, process air cascade flow. The process can optionally include adding a seed sludge containing anammox to a reactor, optionally after pre-treatment and selection. The process can optionally include pre-seeding an MABR media.

A multi-stage system comprising a digester, a bioreactor, a scrubber, a biofilter, and a membrane filter extracts and purifies biogas from a wastewater feed. The digester separates raw biogas from wastewater, the wastewater is then purified with a three-stage bacterial process in a bioreactor. The scrubber receives raw biogas from the digester under pressure, dissolving waste gases and purifying the methane, which can be further condensed and purified in the membrane filter. The bioreactor receives waste gases from the scrubber and membrane filter, with the ammonia portion of the waste gases rising through water from the bioreactor and being converted by annamox bacteria into nitrogen gas. The multiply recycled gas and water feeds produce a biogas having high purity and reduced atmospheric emissions of waste gases.

A method for advanced nitrogen and phosphorus removal of domestic sewage based on DEAMOX in AOAO process with sludge double-reflux is disclosed. The method comprises allowing domestic sewage and returned sludge of the secondary sedimentation tank (3) to enter the anaerobic zone (2.1) of the AOAO reactor (2), firstly performing partial denitrification by the denitrifying bacteria, reducing nitrate-nitrogen in the returned sludge to nitrite-nitrogen, then converting ammonia-nitrogen and nitrite-nitrogen into nitrogen by anammox bacteria, and phosphate accumulating bacteria and denitrifying phosphate accumulating organisms performing anaerobic phosphate release and storing internal carbon source; then allowing part of the mixed liquid to enter the intermediate aerobic zone (2.2) of the AOAO bioreactor (2) to carry out phosphate uptake and nitrification reaction, allowing another part of the mixed liquid to enter the anoxic zone (2.3) of the AOAO bioreactor (2), at same time allowing all the mixed liquid of the intermediate aerobic zone (2.2) and part of returned sludge of the secondary sedimentation tank (3) to enter the anoxic zone (2.3), using the internal carbon source stored in the anaerobic compartment and the internal carbon source in the returned sludge to carry out partial denitrification, anammox, denitrifying dephosphatation, and then allowing the mixed liquid to enter the post aerobic zone (2.4) and subsequently enter the secondary sedimentation tank (3) for mud-water separation. An apparatus for advanced nitrogen and phosphorus removal of domestic sewage based on DEAMOX in AOAO process with sludge double-reflux is also disclosed.

Disclosed is an apparatus and method for synchronously treating sewage and sludge through a step-feed partial nitrification coupling anaerobic ammonia oxidation process, belonging to the biological treatment field. Ammonia rich landfill leachate is firstly pumped into an aerobic reactor to realize partial nitrification process; exogenous surplus sludge coupling with partial nitrification reactor effluent are input to an anoxic reactor together for achieving integrated fermentation and denitrification process; finally, effluent from the anoxic reactor is pumped into an integrated autotrophic nitrogen removal reactor by a step-feed mode, the integrated reactor contains two main running units of aeration and anoxic stirring, ammonia is oxidized into nitrite in aeration stage, and the generated nitrite and ammonia contained in secondary influent are further removed through anammox process which operates stably and reliably, realizes efficient nitrogen removal from landfill leachate without external carbon source addition, and realizes the purpose of exogenous excess sludge reduction simultaneously.

A wastewater treatment system and a wastewater treatment process, fluidly combining a one or more SBR (sequencing batch reactor) module/s, in which nitrification and denitrification of the wastewater are performed in sequences and one or more MBR (membrane bioreactor) module/s.

The disclosure belongs to the technical field of flue gas treatment and provides a method for denitration of flue gas. The method includes in the presence of anammox bacteria, subjecting a NO.sub.x-containing flue gas and an ammonia water to an anammox reaction.

A device and method for shortcut nitrogen removal and nitrite-oxidizing bacteria activity inhibition are disclosed herein. An embodiment of the present invention provides a hollow fiber diffuser comprising: a plurality of hollow fibers on which bacteria can be attached and grow; and an inlet capable of supplying gas to one sides of the plurality of hollow fibers, wherein the gas includes oxygen and carbon dioxide, nitrite can be produced by the oxygen, and the concentration of oxygen in the gas is adjusted by the oxygen and the carbon dioxide.