Abstract: The present invention relates to a system or process for anaerobically treating wastewater. The system employs a pre-treatment unit that includes an MBBR having biomass supported on biofilm carriers. The biomass hydrolyzes or leads to a level of hydrolysis of particulate matter and acidifies the wastewater. In the process, the biomass yields relatively high acid production rates while employing a relatively short hydraulic retention time.

Abstract: The invention pertains to a method (200, 300, 400) of at least partly removing at least one micropollutant from wastewater (104) comprising carbogenous compounds and at least one micropollutant.

Abstract: A carrier element (1; 10; 20) for growth of biofilm thereon is designed for free-flowing in liquid to be purified and has surfaces (3; 13) for biofilm growth which are protected from the abrasion from other carrier elements or surfaces in a container containing the liquid to be purified by ridges (4; 12) having a height corresponding to a desired thickness of a biofilm intended to grow on the protected surfaces (3; 13). The ratio between the surfaces (3; 13) for biofilm growth and the area of the ridges ranges from 1:1 to 1:20.

Abstract: A process for converting ammonium (NH4+) of a mainstream of a wastewater plant to dinitrogen gas (N2), including the consecutive steps of i.) removing biodegradable carbon compounds in the mainstream, ii.) converting ammonium (NH4+) in the mainstream to nitrite (NO2?) in an aerated biological process containing ammonium oxidizing bacteria (AOB) in a nitration vessel (133a-133d); and iii.) denitrifying the resulting stream from step ii.) to dinitrogen gas in an anammox vessel (200). Growth of nitrite oxidizing bacteria (NOB) in step ii.) is prevented by periodically subjecting the bacteria in said nitration vessel (133a-133d) to water suppressing growth of nitrite oxidizing bacteria (NOB).

Abstract: The invention pertains to a method (200, 300, 400) of at least partly removing at least one micropollutant from wastewater (104) comprising carbogenous compounds and at least one micropollutant.

Abstract: A process for converting ammonium (NH4+) of a mainstream of a wastewater plant to dinitrogen gas (N2), including the consecutive steps of i.) removing biodegradable carbon compounds in the mainstream, ii.) converting ammonium (NH4+) in the mainstream to nitrite (NO2?) in an aerated biological process containing ammonium oxidizing bacteria (AOB) in a nitration vessel (133a-133d); and iii.) denitrifying the resulting stream from step ii.) to dinitrogen gas in an anammox vessel (200). Growth of nitrite oxidizing bacteria (NOB) in step ii.) is prevented by periodically subjecting the bacteria in said nitration vessel (133a-133d) to water suppressing growth of nitrite oxidizing bacteria (NOB).

Abstract: A carrier element (1; 10; 20) for growth of biofilm thereon is designed for free-flowing in liquid to be purified and has surfaces (3; 13) for biofilm growth which are protected from the abrasion from other carrier elements or surfaces in a container containing the liquid to be purified by ridges (4; 12) having a height corresponding to a desired thickness of a biofilm intended to grow on the protected surfaces (3; 13). The ratio between the surfaces (3; 13) for biofilm growth and the area of the ridges ranges from 1:1 to 1:20.

Abstract: A process that utilizes ammonium oxidizing bacteria (AOB) and anaerobic ammonium oxidizing (ANAMMOX) bacteria to remove ammonium from a wastewater stream. Sludge separated from the wastewater in a mainstream is processed in a sidestream that includes an anaerobic digester, a dewatering system, and a biofilm reactor. The anaerobic digester produces digested sludge that is dewatered, producing reject water that includes a relatively high ammonium concentration and a relatively low organic carbon concentration and a relatively high temperature. The reject water is treated in a sidestream deammonification biofilm reactor that includes biofilm carriers seeded with AOB and ANAMMOX bacteria that are effective to remove ammonium from the reject water. AOB and ANAMMOX bacteria on the media carriers is utilized to contact the wastewater in the mainstream and to remove ammonium therefrom.

Abstract: A process that utilizes ammonium oxidizing bacteria (AOB) and anaerobic ammonium oxidizing (ANAMMOX) bacteria to remove ammonium from a wastewater stream. Sludge separated from the wastewater in a mainstream is processed in a sidestream that includes an anaerobic digester, a dewatering system, and a biofilm reactor. The anaerobic digester produces digested sludge that is dewatered, producing reject water that includes a relatively high ammonium concentration and a relatively low organic carbon concentration and a relatively high temperature. The reject water is treated in a sidestream deammonification biofilm reactor that includes biofilm carriers seeded with AOB and ANAMMOX bacteria that are effective to remove ammonium from the reject water. In order to remove ammonium from the wastewater in the mainstream, the AOB and ANAMMOX bacteria on the media carriers is utilized to contact the wastewater in the mainstream and to remove ammonium therefrom.

Abstract: A method for biological purification of water such as wastewater using a carrier material is disclosed, wherein the water is treated in a reactor containing carriers for biofilm growth. These carriers are kept in movement in the water and are designed so that they have well-defined passages or compartments providing a surface for biofilm growth, which is protected against collision with the surfaces of other carriers. The carriers have a width or diameter greater than 20 mm, the protected area is larger than 1000 m2/m3 carrier element volume, the length of the passages or the depth of the compartments in the carrier elements as a mean value is smaller than 6 mm or smaller than 3 mm, respectively, and the ratio between the passage lengths or compartment depths and the longest dimension of the inlet openings to the passages or compartments, respectively, is smaller than 3.

Abstract: A method for biological purification of wastewater is disclosed, wherein the wastewater is purified in a biofilm process followed by an activated sludge process. The biological degradation in the biofilm process is performed under limitation of one of the nutrient salts nitrogen or phosphorous, and the surplus sludge from the biofilm process is allowed to pass to the activated sludge process.

Abstract: A method for biological purification of water such as wastewater using a carrier material is disclosed, wherein the water is treated in a reactor containing carriers for biofilm growth. These carriers are kept in movement in the water and are designed so that they have well-defined passages or compartments providing a surface for biofilm growth, which is protected against collision with the surfaces of other carriers. The carriers have a width or diameter greater than 20 mm, the protected area is larger than 1000 m2/m3 carrier element volume, the length of the passages or the depth of the compartments in the carrier elements as a mean value is smaller than 6 mm or smaller than 3 mm, respectively, and the ratio between the passage lengths or compartment depths and the longest dimension of the inlet openings to the passages or compartments, respectively, is smaller than 3.

Abstract: A method for biological purification of wastewater is disclosed, wherein the wastewater is purified in a biofilm process followed by an activated sludge process. The biological degradation in the biofilm process is performed under limitation of one of the nutrient salts nitrogen or phosphorous, and the surplus sludge from the biofilm process is allowed to pass to the activated sludge process.