Biological wastewater treatment of wastewater is performed by oxidizing organic carbon with sulfur or a sulfur compound as an electron carrier, and reducing the sulfur or sulfur compound to sulfide. The sulfide is oxidized with nitrate or oxygen. If necessary, ammonia is oxidized to nitrate and then reduced to nitrogen gas. The process is effective for saline waste water facilities, as well as non-saline waste water facilities.

Processes and apparatuses for the neutralization of wastewater comprising terephthalic acid are provided. Such processes and apparatuses use magnesium hydroxide to neutralize the wastewater upstream of an anaerobic reactor.

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 process for treatment of sludge made up of saline organic solids or organic waste produced in a saltwater or brackish aquaculture system is described. The process includes use of a modified reactor, operating under anaerobic conditions, which yields methane from the digestion of the saline organic solids. Modification of a traditional reactor to include a packing substrate provides for saline waste digestion not previously known. Additionally provided is a process for producing methane from the digestion of organic solids. Inclusion of and use of modified reactors in aquaculture systems is also provided.

The invention relates to a process for reducing the amount of sulphur compounds in a sulphur compounds contaminated wastewater stream, using a granular sludge treatment system (10) comprising anaerobic microorganisms, wherein the process comprises the steps of adding an aqueous nitrate solution to the wastewater stream, contacting the wastewater stream with the anaerobic microorganisms, and anoxic oxidation of at least part of the sulphur compounds in the sulphur compounds contaminated wastewater stream by the anaerobic microorganisms, resulting in a sulphur compounds depleted wastewater stream. The invention furthermore relates to such a granular sludge treatment system (10).

An electroactive bio-carrier module and a sewage treatment device using same are provided, which relate to the field of bioelectrochemistry and sewage treatment. The electroactive bio-carrier module is composed of an anode module and a cathode module made of a conductive material. The anode module is formed by connecting carbon fiber brushes in series and is of a vertically ring type structure; the cathode module is formed by connecting stainless steel meshes in series; the stainless steel meshes are in a folded horizontal stacked design; the anode and cathode modules are connected through an external lead wire to form a circuit. Surfaces of the anode and cathode modules can both enrich microorganisms, biofilms are formed on the surfaces. The electrode module is arranged in an up-flow type sewage treatment device and is used as an electroactive bio-carrier, to form a hybrid sewage treatment device with a built-in electroactive bio-carrier.

Apparatus and method for mixing a tank containing a fluid with a gas, wherein the gas is fired with a periodic intensity and duration through the employment of a gas container containing an inverted siphon, with one end contained in the container and the other end extending into a fluid.

The invention relates to a process of microbiologically treating an aqueous liquid comprising biodegradable substrate in an installation comprising (i) a bioreactor containing a biomass sludge and (ii) a biomass separator that is separated from the bioreactor and that comprises one or more inclined plate settlers, wherein the biomass separator has a footprint area A of 0.5 to 30 m.sup.2 and the one or more inclined plate settlers comprise a total number of n inclined plate elements which together provide a total projected surface area (PSA) and a total projected surface area ratio (PSAR) that are calculated as follows:

[00001]$PSA={.Math.}_{i=1}^{n}ps{a}_i$$PSAR=PSA/A$

psa.sub.i representing the aggregate projected surface area of inclined plate element i in m.sup.2; and wherein PSAR2.8+0.17 A.

The installation that is used to operate the process of the present invention can achieve solid-liquid separation in the biomass separator at a very high fluid flow velocity, without compromising on separation efficiency and without substantially increasing the total footprint of the installation.

The invention also provides an installation for microbiologically treating an aqueous liquid comprising a biodegradable substrate.

A process for anaerobically treating a feed of manure that contains liquid and suspended solid in a reaction that uses a multicell lagoon reactor (MCLR) wherein the reaction system has an input cell, an output cell, and one or more intermediate cell all in series and located at least partially below the ground. A partition separates the cells to restrict a gravity induced flow of liquid and solids retained cell. The solids retention time exceeds the hydraulic retention time in each cell. Enclosing the cells enables collecting of biogas from the cells. At least an input cell operates as an anaerobic sequencing batch reactor that undergoes periodic mixing. An output cell provides treated liquid for recovery.

A low-carbon near zero emission process of industrial waste water, comprising: S1: entering industrial waste water into a pre-oxidation system to improve biodegradability of organics; S2: after treatment in the pre-oxidation unit, entering the waste water into an anaerobic biological treatment system, sodium chloride and sulfate is deeply removed and carbon sources in the waste water can be used to remove the sulfate and nitrate; S3: entering water output from the anaerobic biological treatment system into a membrane concentration system and membrane concentrated solution enters a nano-filtration salt fractionation system for salt fractionation; and S4: refluxing nano-filtration concentrate solution generated by the nano-filtration salt fractionation system to the anaerobic biologic treatment system for biological desulfurization, or synthesizing the nano-filtration concentrate solution to be sodium persulfate by electro chemical methods, and refluxing proportionately to a waste water pre-oxidation system for use in-situ.