A common final clarifier is provided downstream of a two-stage or three-stage activated sludge (AS) system that includes: (A) one or more flow equalization basin (FEB) reactors and a nitritation reactor as the first AS stage, and an anammox reactor as the second AS stage, or (B) a carbonaceous biological oxygen demand (BOD) removal reactor and one or more FEBs as the first AS stage, a nitritation reactor as the second AS stage, and an anammox reactor as the third AS stage. A first return activated sludge (RAS) flow is conducted from the final clarifier to the first AS stage and a second segregated RAS flow is conducted to the second AS stage. Alternatively, a third segregated RAS flow is conducted to the third AS stage.

A system and method for passive capture of ammonia in an ammonia-containing liquid effluent. The invention allows for the passage of ammonia through microporous hydrophobic gas-permeable membranes and its capture in a circulated stripping solution with concomitant production of a concentrated non-volatile ammonium salt.

A fluidized bed reactor for ammonia laden wastewater includes a column, a plurality of carrier particles, a first settling tank and a fluidizing means. The column defines a fluidizing chamber therein, and the fluidizing means is adapted for introducing the ammonia laden wastewater into the fluidizing chamber and further into the first settling tank. The reactor is further provided with microorganisms including nitrifying bacteria, anammox bacteria and heterotrophic denitrifying bacteria attached to the carrier particles. Nitrification reaction, anammox reaction and heterotrophic denitrification reaction are simultaneously taking place in the fluidizing chamber to transform ammonia into nitrogen by the microorganisms. A method for treating ammonia laden wastewater is also provided. The fluidized bed reactor is advantageous in the fact that its start-up is significantly shortened and it is adapted to efficiently treat thin ammonia laden wastewater.

The present invention provides an aeration lateral system designated to be site specific for new septic disposal areas or retro fitting to existing septic disposal areas to break up the biological clogging slug mat at the interface of the wastewater and imported sand or native soil fill under or adjacent to disposal areas of a typical septic system. The lateral system provides uniform or other site specific distribution of fluids about the bio-mat of a wastewater disposal area, with lateral spacing and hole spacing varying based on the type of disposal area being utilized. The lateral system can also be utilized to provide continuous low volume air supply system to a wastewater disposal area or peat filter module. The air lateral installation includes methods to minimize airflow disturbance of the soil and methods to prevent air leakage.

A method for treating wastewater containing TMAH and ammonium nitrogen includes the steps of (a) introducing a first solution which contains ammonium nitrogen but no TMAH into a single reactor with microorganisms comprising nitrifying bacteria and anammox bacteria, and denitrifying the first solution by the microorganisms under a dissolved oxygen concentration ranging from 0.1-0.5 mg/L and a pH value of 7-8; (b) when the denitrification efficiency reaches a steady state, introducing a second solution which contains ammonium nitrogen and TMAH and has a concentration of TMAH lower than 60 mg/L into the reactor; and (c) gradually increasing the concentration of TMAH in the solution to be added into the reactor for several times whenever the denitrification efficiency reaches a steady state. Accordingly, the inhibition of TMAH to the anammox bacteria can be significantly decreased, and both TMAH and the ammonium nitrogen can be treated simultaneously.

A device and method for enhancing nitrogen and phosphorus removal based on a multistage AO partial denitrification coupled with Anammox process in combination with a sludge hydrolytic acidification mixture belong to the technical field of active sludge method wastewater treatment. A system includes a water tank, a water pump, a biochemical reaction zone, a hydrolytic acidification tank and other devices. A multistage AO step-feed pipeline is used to inject raw water into the reaction zone in a segmented manner, guaranteeing efficient utilization of organic matter in the raw water; biofilm carriers are added into an anaerobic zone and anoxic zones to enrich anammox bacteria, and nitrite nitrogen produced by partial denitrification provides a substrate for the anammox bacteria to realize autotrophic nitrogen removal; a nitrification and phosphorus accumulating bacteria aerobic phosphorus uptake are performed in aerobic zones; and part of excess sludge in a secondary sedimentation tank enters the hydrolytic acidification tank to convert macromolecular organic matter into low molecular weight organic matter, a hydrolytic acidification mixture and the excess sludge in the secondary sedimentation tank synchronously flow back to the anaerobic zone, and as a high-quality carbon source, the low molecular weight organic matter can promote partial denitrification. The system provides a novel method for efficient and energy-saving treatment of municipal wastewater.

A methodology, system and apparatus are provided that include anoxic biofilms to perform partial denitrification and anammox (PdNA) reactions. The PdNA reactions can facilitate process intensification and carbon efficient biological nitrogen removal. The anoxic biofilms can be placed in a pre-anoxic zone or a downstream anoxic zone, where the biofilm and reactions are managed, including using storage compounds, to overcome mass transfer limitations in the biofilm. The methodology, system and apparatus can, when compared to state-of-the art technologies, improve the concentration gradient or reduce mass transfer limitations to facilitate PdNA reactions.

Methods and systems are provided for treating wastewater to simultaneously remove nitrogen, carbon, and phosphorus, while recovering energy in the form of methane and carbon dioxide. An ammonia-containing stream is directed to a pretreatment tank that produces excess sludge, biogas, and a pretreated stream. The pretreated stream has at least 45% less carbon than the ammonia-containing stream. The pretreated stream is then directed to an anoxic tank, which promotes phosphorus release and fermentation of particulate and dissolved organic matter. The mixed liquor is transferred to an aerated tank having low dissolved oxygen concentrations to promote development of phosphorus-release bacteria that is eventually recycled to the anoxic tank by way of the return activated sludge. Simultaneous nitrification, denitrification, and phosphorus release occur in the aerated tank. A membrane tank separates treated effluent from activated sludge in a membrane tank.

A common final clarifier is provided downstream of a two-stage activated sludge (AS) system that includes a flow equalization basin (FEB) reactor and a nitritation reactor as the first AS stage and an anammox reactor as the second AS stage. A first return activated sludge (RAS) flow is conducted from the final clarifier to the first AS stage with a low flow rate and a second segregated RAS flow is conducted to the second AS stage with a high flow rate. The FEB reactor is operated as an anoxic reactor to achieve carbonaceous BOD removal; conversion of organic nitrogen to ammonia nitrogen; and, denitrification of recycled nitrite or nitrate nitrogen. The nitritation reactor is operated as an aerobic reactor to achieve oxidation of ammonia nitrogen to nitrite nitrogen by biological nitritation. The anammox reactor is operated at zero or very low dissolved oxygen concentration to achieve nitrogen removal by deammonification.

In order to treat a flow of waste water, there is applied to this flow, after at most an optional pre-treatment of screening/degritting or deoiling, a filtration treatment by means of microfiltration or ultrafiltration membranes, by causing the flow to circulate tangentially to the membranes at a velocity of at least 0.1 m/s, in the presence of an organic sequestering agent composed based on organic phosphate at a concentration that is effective for sequestering metal ions contained in the flow and minimizing the formation of calcium carbonate, with a differential pressure on either side of the membranes that is less than or equal to 5 bar.