ISSN 0003-6838, Applied Biochemistry and Microbiology, 2012, Vol. 48, No. 8, pp. 667–684. © Pleiades Publishing, Inc., 2012. Original Russian Text © A.N. Nozhevnikova, M.V. Simankova, Yu.V. Litti, 2011, published in Biotekhnologiya, 2011, No. 5, pp. 8–31. 667 In the modern world, the amount of generated wastewater is ever increasing as a result of domestic and industrial activity, which demands an efficient and cheap method of decontamination. The basis for bio- logical decontamination of wastewater, which remains the most economical and environmentally friendly process, is aerobic and/or anaerobic degradation and mineralization of organic matter by microorganisms. The development and improvement of the existent methods of biological decontamination of wastewater from pollution is an extremely important task, as the wastewater that gets into the environment affects the quality of fresh water drastically. The global problem of drinking water is inseparable from the problem of wastewater treatment and prevention of the contami- nation of fresh water. Ammonium nitrogen is one of the major nutrients contained in wastewater. The decontamination of wastewater from nitrogen compounds is performed in the nitrification–denitrification process, where ammonium is first oxidized to nitrate, which is fol- lowed by the assimilation of carbon dioxide (nitrifica- tion) and subsequent reduction of nitrate to nitrogen gas (denitrification) [1]. The process of nitri-denitrifi- cation is quite expensive because of the high costs of aeration and nutrients, which are needed for the growth of denitrification microorganisms. The energy consumption for aeration, which is needed for the nitrification stage, could be as high as 80% of the total energy consumption (nitrification–denitrification) [2]. If the treated water does not contain a sufficient source of organic carbon, the addition of electron donors could be needed at the denitrification stage. Nitrification–denitrification technologies are used for the treatment of wastewater that have both an organic content and a low nitrogen content. Thus, the process of denitrification is used for urban wastewater treat- ment where the initial BOC 5 /nitrogen ratio is not less Application of the Microbial Process of Anaerobic Ammonium Oxidation (ANAMMOX) in Biotechnological Wastewater Treatment A. N. Nozhevnikova, M. V. Simankova, and Yu. V. Litti Vinogradskii Institute of Microbiology, Russian Academy of Sciences, Moscow, 117312 Russia e-mail: nozhevni@mail.ru, msimankova@mail.ru Received July 6, 2011 Abstract—This review covers various aspects of the process of anaerobic ammonium oxidation by nitrite with the formation of molecular nitrogen called ANAMMOX (ANaerobic AMMonium Oxidation). Anaerobic ammonium oxidizing bacteria are briefly described, including their phylogenetics, habitat, and morphologi- cal and physiological characteristics. The current views on the biochemistry of the microbial nitrite reduction by ammonium are presented. The review is focused on biotechnological wastewater treatment based on the ANAMMOX process. Various nitrogen removal technologies using this process, namely, the SHARON- ANAMMOX CANON and DEAMOX BC-DEAMOX, and their practical use are reviewed. Various types of reactors and set ups using the ANAMMOX process that are applied to the treatment of wastewater are ana- lyzed. Processing methods for slowly growing ANAMMOX bacterial biomass accumulation aimed at subse- quent inoculation in reactors are analyzed. The problems and methods for ANAMMOX bacterial biomass immobilization in reactors and on carriers are described. A description and parameters of laboratory and pilot plants utilizing various high-ammonia wastewater are given. Examples of the currently operating full-scale industrial setups with the ANAMMOX process implementation, including those for the complex biochemi- cal treatment of domestic sewage (BC-DEAMOX) constructed by EKOS (Russia) at the Olympic facilities in the Sochi region, are discussed. Keywords: ANAMMOX, ANAMMOX bacteria, anaerobic ammonium oxidation, BC-DEAMOX, DEAMOX, denitrification, nitrification, wastewater decontamination, planctomycetes, CANON, SHARON-ANAMMOX DOI: 10.1134/S0003683812080042 Abbreviations: AOB, ammonium-oxidizing bacteria; BOD, bio- logical oxygen demand; VFA, volatile fatty acids; NOB, nitrite- oxidizing bacteria; IRBC, immersed rotating biological contrac- tor; DM, dry matter; MSW, municipal solid waste; COD, chemi- cal oxygen demand; ABF reactor, anaerobic biological filtrated reactor; CANON, completely autotrophic nitrogen removal over nitrite; DEAMOX, denitrifying ammonium oxidation; FISH, flu- orescent in situ hybridization; RBC, rotating biological contac- tor; SBR, sequential batch reactor; SHARON, single-reactor high-activity ammonium removal over nitrite; UASB reactor, up- flow anaerobic sludge blanket reactor. PROBLEMS, PERSPECTIVES