The invention relates to a method for purifying sulphate containing wastewater and recovering sulphur species and hydrogen, comprising of converting sulphates of the sulphate containing wastewater to hydrogen sulphide in an anaerobic bioreactor, stripping the hydrogen sulphide into a gas phase and converting the hydrogen sulphide containing gas phase to a sulphide salt in a scrubber arrangement. Thereafter, the sulphide salt is subjected to electrolysis and hydrogen gas, hydroxide and elemental sulphur are recovered.

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.

A gas-liquid-solid separator can include a separator body having a vertical outer wall and a gas collector having a vertical gas collector wall surrounded by the outer wall, with a gas inlet opening at a bottom of the gas collector. An annular volume between the gas collector wall and the outer wall can contain a plurality of inclined flow channels. The flow channels can have a channel inlet opening at the bottom and can slope upward following a helical path between the gas collector wall and the outer wall. A gas-liquid-solid mixture inlet opening can be in a floor of the separator body. The mixture opening can be positioned below the gas inlet opening and the mixture inlet opening can have a top-down profile that fits within a top-down profile of the gas inlet opening.

Provided herein are systems and methods for treating a wastewater stream. In one embodiment, a wastewater stream is treated using a settling tank, a membrane feed tank, and at least one filtration unit.

The present invention relates to a method and to a device for continuous cleaning of process water circulating in a device for treating waste paper. The process water is supplied, from a unit of the device, to an anaerobic reactor comprising a gas separator, and the cleaned process water is returned back to a unit of the device, wherein this unit is selected from: a pulper; screening device; dewatering unit; oxidation/reduction unit; centrifugal screening device; fine screening device; paper-machine mould section; paper-machine press section; reject treatment unit; fibre recovery unit; and drying section; wherein the content of inorganic solids in the reactor is measured and, if this content exceeds a pre-set limit value, process water from the reactor is continuously fed to a solid-liquid separator for separation into a fraction that is depleted of inorganic solids and a fraction that is enriched with inorganic solids, wherein the fraction that is depleted of inorganic solids is returned to the anaerobic reactor and the fraction that is enriched with inorganic solids is conveyed away out of the device, until the content of inorganic solids in the process water is less than the limit value.

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.

A method for treating an aqueous fluid comprising a biodegradable organic substance in an installation comprising an upflow bioreactor containing a sludge bed, said sludge bed comprising biomass, an external separator, and a conditioning tank, the method comprising: treating the fluid in the conditioning tank; feeding the treated fluid into a lower part of the bioreactor and forming biogas; withdrawing the fluid from an upper part of the bioreactor, which withdrawn fluid comprises biomass; feeding the aqueous fluid withdrawn from the upper part of the bioreactor into the external separator wherein the aqueous fluid comprising the biomass is separated into a liquid phase, and a fluid phase enriched in biomass; returning said fluid phase enriched in biomass from the external separator to the bioreactor; and returning a part of said liquid phase to the conditioning tank.

The invention is directed to a process for the degradation of one or more hydrocarbons as present in an aqueous feed solution, wherein the one or more hydrocarbons are at least one of phenol, methyl phenyl ketone and methyl phenyl carbinol. The degradation takes place in a series of two or more continuously operated bio-electrochemical cells thereby defining at least one upstream bio-electrochemical cell and one downstream bio-electrochemical cell and wherein an applied cell voltage in each bio-electrochemical cell is different. The bio-electrochemical cell comprises a culture of microorganisms. The one or more hydrocarbons are converted at the anode whereby carbon dioxide, protons and optionally degradation products are formed. At the cathode carbon dioxide and/or the optional degradation products are reacted with the protons to methane. A treated aqueous solution is so obtained having a reduced content of the one or more hydrocarbons.

Provided herein are systems and methods for treating a wastewater stream. In one embodiment, a wastewater stream is treated using a settling tank, a membrane feed tank, and at least one filtration unit.