A process for treating an aqueous fluid comprising a biodegradable organic substance the process comprising a bioreactor unit batch feeding stage, wherein the aqueous fluid that is to be treated is fed into a bioreactor unit; a batch reaction stage, wherein the aqueous fluid is microbiologically treated and biogas is produced in the bioreactor unit; a degassing unit feeding stage, wherein an aqueous suspension comprising microbiologically treated aqueous fluid and biomass is withdrawn from the bioreactor unit and fed batch-wise into a degassing unit; and a semi-continuous biomass separator unit feeding stage, wherein the degassed aqueous suspension is withdrawn from the batch degassing unit and fed into a biomass separator.

A process for treating an aqueous fluid comprising a biodegradable organic substance the process comprising a bioreactor unit batch feeding stage, wherein the aqueous fluid that is to be treated is fed into a bioreactor unit; a batch reaction stage, wherein the aqueous fluid is microbiologically treated and biogas is produced in the bioreactor unit; a degassing unit feeding stage, wherein an aqueous suspension comprising microbiologically treated aqueous fluid and biomass is withdrawn from the bioreactor unit and fed batch-wise into a degassing unit; and a semi-continuous biomass separator unit feeding stage, wherein the degassed aqueous suspension is withdrawn from the batch degassing unit and fed into a biomass separator.

A device for preparing high-purity hydrogen and/or oxygen by electrolyzing water, including an electrolyzer and a degasser for degassing desalted water. The degasser is located at the upstream of the electrolyzer. After desalted water is heated and degassed in the degasser, the content of gaseous impurities, particularly argon, can be reduced to several ppb (weight ratio). The hydrogen and oxygen generated after the desalted and degassed water is electrolyzed in the electrolyzer also contain an extremely small amount of argon, so that the requirements in semiconductor industry are met. Also involved is a method of preparing high-purity hydrogen and/or oxygen by using the device.

A device for preparing high-purity hydrogen and/or oxygen by electrolyzing water, including an electrolyzer and a degasser for degassing desalted water. The degasser is located at the upstream of the electrolyzer. After desalted water is heated and degassed in the degasser, the content of gaseous impurities, particularly argon, can be reduced to several ppb (weight ratio). The hydrogen and oxygen generated after the desalted and degassed water is electrolyzed in the electrolyzer also contain an extremely small amount of argon, so that the requirements in semiconductor industry are met. Also involved is a method of preparing high-purity hydrogen and/or oxygen by using the device.

Disclosed is a system for producing magnesium hydroxide including: a generation unit; and a recovery unit connected to the generation unit, wherein the generation unit has a reaction tank in which a calcium hydroxide slurry is added to water to be treated containing magnesium ions to crystallize magnesium hydroxide and to obtain a reaction slurry containing particles of magnesium hydroxide, and a sedimentation tank in which the reaction slurry is reserved to sediment the particles and to separate the reaction slurry into a separation slurry containing the particles at a high concentration and a separation liquid containing the particles at a low concentration, and wherein, in the recovery unit, an alkaline aqueous solution is added to the separation liquid to crystallize magnesium hydroxide and to obtain the reaction slurry and then the reaction slurry is reserved to sediment the particles and to recover the sedimented particles.

The present invention is in the field of a system for gas recovery from wastewater, a method for treating wastewater, and a method wherein ammonia and carbon dioxide are recovered. Typically a wastewater stream is fed into the system, treated and stripped from ammonia and carbon dioxide, and a cleaner stream is released.

The present invention is in the field of a system for gas recovery from wastewater, a method for treating wastewater, and a method wherein ammonia and carbon dioxide are recovered. Typically a wastewater stream is fed into the system, treated and stripped from ammonia and carbon dioxide, and a cleaner stream is released.

Provided is an ultrafine bubble generating apparatus that generates ultrafine bubbles by generating film boiling by causing a heater provided in a liquid to generate heat, the ultrafine bubble generating apparatus including: an element substrate including a first heater that generates the film boiling in the liquid and a second heater that is arranged adjacent to the first heater, in which the first heater and the second heater are driven in different timings.

A purification device for water has a housing with a longitudinal axis, an upper and a lower end and a substantially round cross section. The device includes a first receptacle, arranged parallel to the longitudinal axis of the housing, for a first purification medium, and a second receptacle, which is also arranged parallel to the longitudinal axis of the housing, for a second purification medium. The receptacle for the second purification medium is arranged eccentrically with respect to the longitudinal axis of the housing.

The present invention relates to a process for purifying a wastewater stream WW1 contaminated with nitrobenzene, comprising (I) stripping of the wastewater stream WW1 with a stripping gas SG1 in a continuously operated stripping column to obtain a wastewater stream WW2 which contains nitrobenzene in a concentration reduced relative to WW1 (c.sub.NB,WW2), (II) further purification of the wastewater stream WW2 in a wastewater treatment plant, wherein a target value (c.sub.NB,WW2,TARGET) is specified for the concentration of nitrobenzene in the wastewater stream WW2, which is greater than zero but takes into account the requirements of the wastewater treatment plant for the maximum content of nitrobenzene in the wastewater streams supplied thereto, wherein, for at least one combination of specified boundary conditions of (a) nitrobenzene concentration in WW1, (b) the temperature of WW1, and (c) the temperature of SG1, a set of linear mathematical relationships of the type m.sub.SG1=x.Math.m.sub.WW1 is stored in a database, which linear mathematical relationships define a range of concentrations of nitrobenzene in WW2, wherein the set comprises, in addition to a mathematical relationship (0) which corresponds to the target value c.sub.NB,WW2,TARGET, at least a first mathematical relationship (1) for a first value of c.sub.NB,WW2, which corresponds to 98% of the target value c.sub.NB,WW2,TARGET, and a second linear mathematical relationship (2) for a second value of c.sub.NB,WW2, which corresponds to 102% of the target value c.sub.NB,WW2,TARGET, and wherein the flow rate of the stripping gas is adapted to the flow rate of the wastewater WW1 such that the flow rate of WW1 is within a range of values (AB) that is generated by the first mathematical relationship (1) and the second mathematical relationship (2) at the respective flow rate of WW1, and controlling the concentration of nitrobenzene in WW2 (c.sub.NB,WW2) by adjusting the flow rate of stripping gas SG1 accordingly in the event of a measured actual value of this concentration which is outside a window of >98% to <102% of the target value.