New concepts of microbial treatment processes for the nitrogen removal in wastewater

Abstract

Many countries strive to reduce the emissions of nitrogen compounds (ammonia, nitrate, NOx) to the surface waters and the atmosphere. Since mainstream domestic wastewater treatment systems are usually already overloaded with ammonia, a dedicated nitrogen removal from concentrated secondary or industrial wastewaters is often more cost-effective than the disposal of such wastes to domestic wastewater treatment. The cost-effectiveness of separate treatment has increased dramatically in the past few years, since several processes for the biological removal of ammonia from concentrated waste streams have become available. Here, we review those processes that make use of new concepts in microbiology: partial nitrification, nitrifier denitrification and anaerobic ammonia oxidation (the anammox process). These processes target the removal of ammonia from gases, and ammonium-bicarbonate from concentrated wastewaters (i.e. sludge liquor and landfill leachate). The review addresses the microbiology, its consequences for their application, the current status regarding application, and the future developments.

Polishing of Secondary Effluent by a Two-Stage Vertical-Flow Constructed Wetland

“…4 sampling tap, the denitrification began to proceed. Denitrification is most commonly defined as the process in which nitrate is converted into dinitrogen via intermediates nitrite, nitric oxide, and dinitrogen via intermediates nitrite, nitric oxide, and nitrous oxide [19,20]. From the biochemical point of view, denitrification is a bacterial process in which nitrogen oxides (in ionic and gaseous forms) serve as terminal electron acceptors for respiratory electron transport.…”

Anodic ammonia oxidation to nitrogen gas catalyzed by mixed biofilms in bioelectrochemical systems

“…Ammonia-N pollution, which can cause eutrophication and be toxic to aquatic species, is usually converted into nitrogen gas via anaerobic ammonium oxidation (ANAMMOX) or nitrification/denitrification [1]. However, additional nitrite-N is necessary for anammox reaction and the cultivation of the anammox bacteria is difficult [2].…”

Landfill leachate treatment with a novel process: Anaerobic ammonium oxidation (Anammox) combined with soil infiltration system

“…In this way, Anammox combined with partial nitritation (partial nitritation-Anammox), a completely autotrophic nitrogen removal technology is achieved. Compared with the conventional biological treatment technologies, the process may have promising technical and economic advantages for landfill leachate treatment because of less oxygen consumption, no organic source addition and low sludge production [19,20].…”