A method for treating effluents containing nitrogen in the form of ammonium, implementing chemical reactions for oxidizing and reducing the nitrogen in a sequencing batch reactor, the method including: introducing a volume of effluents to be treated into the reactor, injecting oxygen or air into the reactor for partial oxidation of the ammonium into nitrites and/or nitrates, interrupting the injection of oxygen or air, thus producing gaseous nitrogen, depositing the sludge at the bottom of the reactor and clarifying the content of the reactor close to the surface of same, discharging a clarified fraction of the content of the reactor. The draining and feeding steps occur simultaneously. During the feeding step, the volume of effluents is introduced close to the bottom of the reactor. During the draining step, the clarified fraction of the content of the reactor is discharged close to the surface of the content of the reactor.

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.

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.

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t−1), where K is a gain (K>1), and Q(t−1) is an amount of inflow of the water-to-be-treated during a time period t−1 immediately prior to the time period t.

A modular liquid waste treatment system is disclosed. In accordance with some embodiments, the system includes a central distribution unit and one or more treatment fins in flow communication therewith. The distribution unit may be configured to receive liquid waste from a given source and distribute that waste, at least in part, to one or more treatment fins. In turn, bacteria present in a given treatment fin treat the liquid waste, and the resultant treated liquid may drain from the fin to the surrounding environment. In some embodiments, a given treatment fin may include porous media providing a large surface area on which bacteria may grow to facilitate treatment. The system may be installed in and/or above the ground, and in some cases may be surrounded, at least in part, with treatment sand and/or other treatment media. The system may be used in aerobic and/or anaerobic processing of liquid waste.

Aerobic processes are disclosed for the treatment of wastewater which contains at least one substrate comprising at least one of organocarbon component and ammonium cation. A bioreactor is used for the treatment which contains ME biocatalysts to provide high bioreactor bioactivity density. The processes reduce sludge generated and are capable of effecting the metabolic oxidation at low dissolved oxygen concentrations.

A redox water treatment method comprises first determining the composition of water and whether water treatment requires either oxidation or reduction, or both to optimize nitrogen removal by a bioreactor. Sulfur dioxide (SO.sub.2) is injected into the water to be treated to provide H.sup.+, SO.sub.2, SO.sub.3.sup.=, HSO.sub.3.sup.−, dithionous acid (H.sub.2S.sub.2O.sub.4), and other sulfur intermediate reduction products forming a sulfur dioxide treated water, which behaves either as a reducing agent or an oxidizing agent depending on the strength of the acid concentration, which alters sulfurous acid from a reducing agent to a more powerful oxidizing agent.

Installation and method for processing wastewater, comprising: a) providing wastewater for processing; b) reducing O2 content of said wastewater by unactivated aerobic digestion; c) subsequently to ‘b’, eliminating substantially all O2 from said wastewater by anaerobic digestion; d) subsequently to ‘c’, transferring said wastewater to a closed photobioreactor; and e) subsequently to ‘d’, maintaining said wastewater in said photobioreactor in conditions favorable for algal photosynthesis, thereby allowing algae to grow in said photobioreactor. A method for growing algae is also disclosed whereby time, density and flow speed are controlled. The photobioreactor may have a conduit with two proportions of different cross sections.

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.

The present invention relates to an apparatus for biological sewage treatment, including a concentrated mixed liquor driving device that uses a gas to drive a concentrated mixed liquor to flow. The present invention further relates to a method for biological sewage treatment, including a step of using a gas to drive a concentrated mixed liquor to flow. The gas can be an aeration gas, especially an oxygen-containing aeration gas after aeration treatment. The apparatus and method of the present invention can sufficiently utilize the energy and oxygen of the aeration gas, so that the energy consumption and maintenance cost of whole apparatus are reduced, biological sewage treatment effects are improved, and sludge floating is prevented. In addition, the apparatus of present invention has advantages of high performance, energy saving, high reliability, and good movability.