An aeration nozzle is provided, having on one end an air supply port (16a) connected to an aeration pump (13) and a waste water suction port (17) for suctioning waste water in a processing tank (3, 4), and having a micro-bubble generation unit (18), provided facing the air supply port, for mixing air supplied by the air supply port and waste water suctioned from the waste water suction port and generating micro-bubbles (9), wherein a plurality of blades of cylindrical micro-bubble generators (19) included in the micro-bubble generation unit (18) is configured such that tip ends of the blades are formed so as to face one another around the center of the cylindrical micro-bubble generators (19a, 19b); and by being formed from an elastic member (such as rubber), the tip ends of the blades are configured so as to bend with the base ends as starting points.

Integrated methanogenic anaerobic reactor and membrane bioreactor, and method for eliminating organic matter and nitrogen in urban or industrial wastewater, preferably with COD concentrations between 150 and 5000 mg/L and where the eliminations of total nitrogen that occur are between 15 and 50 mg/L, at temperatures above 15° C. The wastewater treatment takes place thanks to three stages of treatment: methanogenic anaerobic stage, anoxic stage with biofilms and suspended biomass and aerobic filtration stage with biofilms and suspended biomass.

There are provided processes for treating wastewater. The processes can comprise treating a mixture comprising the wastewater and an activated sludge, in a single reactor, with an electric current having a density of less than about 55 A/m.sup.2, by means of at least one anode and at least one cathode that define therebetween an electrical zone for treating the mixture; exposing the mixture to an intermittent ON/OFF electrical exposure mode to the electric current in which an OFF period of time is about 1 to about 10 times longer than an ON period of time; and maintaining an adequate oxidation-reduction potential in the single reactor. Such processes allow for substantial removal of carbon, nitrogen and phosphorus from the wastewater in the single reactor of various forms and for obtaining another mixture comprising a treated wastewater and solids.

A water cleaning system 1 includes an aerobic region 90 including breeding water 9 containing organic matter and oxygen, an aerobic layer 6 linking with the aerobic region 90 and inhabited by aerobic bacteria, a facultative anaerobic layer 5 provided adjacent to the aerobic layer 6 and inhabited by facultative anaerobic bacteria, an obligatory anaerobic layer 4 provided adjacent to the facultative anaerobic layer 5, inhabited by obligatory anaerobic bacteria, and made of andosol 40, an anaerobic space 3 having an anaerobic environment, allowing the obligatory anaerobic bacteria inhabiting the obligatory anaerobic layer 4 and products therefrom to flow therein, and a tube 18 as linking means linking the anaerobic space 3 and the aerobic region 90.

Processes and compositions for removal nitrogen, organic and inorganic contaminants from wastewater using Feammox bacterium are provided.

Process for treating effluents containing nitrogen in ammonium form, using a sequential biological reactor (1), according to which: a volume of effluents to be treated in one complete cycle is introduced into the biological reactor in one or more successive fractions by volume, each fraction by volume being treated during a subcycle; each subcycle comprises a phase of feeding with a fraction by volume, and at least a first aerated step, during which total or partial oxidation of the ammonium to nitrites takes place by injection of air or of oxygen into the effluent, a settling out and emptying step taking place after the end of the complete cycle; the weight of N—NH.sub.4 to be treated is determined from the volume of effluents in the reactor at the end of the feeding phase, and from the difference between the initial N—NH.sub.4 concentration in the reactor and a concentration desired at the end of the aerated step, a maximum aeration time TM is dedicated to the aerated step, and an initial air flow rate Qairinit, for the beginning of the aerated step, is determined by taking into account the weight of N—NH.sub.4 to be treated and the maximum aeration time TM.

A bioreactor for anaerobic, aerobic and anoxic digestion of organic matter from wastewater, having a bottom anaerobic zone where the wastewater is fed where anaerobic bacteria produces biogas and the sludge produced is deposited on the bottom and subsequently extracted. An anoxic middle zone contains denitrifying bacteria which converts nitrates to nitrogen, and an aerobic zone at the upper part where at least one biological contact rotor is disposed, which degrade organic matter remaining in the water. The growth of nitrifying bacteria converts ammonia nitrogen into nitrites and nitrates. The tank has a plurality of rhomboids for biogas, sludge and scum collection that join together form a intermediate polyhedral separator panel. The rhomboids joined together define conical collectors with connecting nozzles of ducts from a capture and conduction network of biogas and funnel-shaped manifolds with connecting nozzles of ducts that define a capture and conduction network of sludge and scum.

A process approach allows economical self-sustained operation of single vessel biotreatment systems for municipal wastewater treatment. The daytime solar powered treatment process is changed during darkness periods to operate the biotreatment system without electric grid powering.

A method for removing phosphorus by gasification, the method including: a) providing a membrane bioreactor including a reaction tank and a membrane separation system; b) aerating the reaction tank to control a redox potential in the reaction tank to be higher than −200 mV; and c) controlling the dissolved oxygen concentration around the membrane separation system to be greater than 0 and smaller than 2 mg/L and the dissolved oxygen concentration in the reaction tank excluding the membrane separation system to be greater than 0 and smaller than 1 mg/L, and allowing the dissolved oxygen concentration around the membrane separation system to be higher than the dissolved oxygen concentration in the rest zones of the reaction tank. A phosphorus removal system by gasification includes: a reaction tank, a membrane separation system, a water production system, an aeration system.

A method of wastewater treatment using a membrane bioreactor, including: controlling aeration to enable a dissolved oxygen concentration to be 0 to 1.5 mg/L, and keeping the integrated reaction vessel under a facultative environment. A wastewater treatment system by the membrane bioreactor without physical area division includes a reaction vessel, a membrane separation system, a water production system, and an aeration system. The membrane separation system is disposed inside the reaction vessel. The water production system communicates with the membrane separation system to pump filtrate out of the membrane separation system. The aeration system is employed to aerate the reaction vessel and the membrane separation system.