81 DEAMMONIFICATION PROCESS IN THE MEMBRANE ASSISTED BIOREACTOR J. Surmacz-Górska, G. Cema and K. Miksch Department of Environmental Biotechnology, Silesian University of Technology, Akademicka 2, 44 100 Gliwice, Poland (E-mail: jsgorska@polsl.gliwice.pl, zijo6@wp.pl, kmiksch@zeus.polsl.gliwice.pl) ABSTRACT Conventional ammonia-rich wastewater nitrification/denitrification usually requires a large amount of energy for aeration and an addition of organic carbon, which becomes a major cost factor. In comparison with classical nitrification/denitrification, deammonification is a process which allows reducing both aeration and the addition of external- carbon source to the system. This paper presents the possibility of implementation of the deammonification process into the membrane assisted bioreactor. In one of the reactors partial nitrification was observed while in the other reactor the observed anammox process resulted in 20% nitrogen removal and gas was produced. This paper gives only rough ideas of how the system works. KEYWORDS Anammox, deammonification, membrane-assisted bioreactor, nitrogen removal INTRODUCTION Processes of micro – and ultrafiltration become more and more popular in environmental engineering. Membrane-assisted bioreactor (MBR) is a system, which combines activated sludge process with micro - or ultrafiltration membranes. The use of membrane instead of the secondary clarifier in the processes of the wastewater treatment generates a lot of advantages, for example high efficiency of selectivity, which results in good quality of the effluent, retention of all the biomass, which effects in facilitating of the sludge retention time (SRT) control, reliability of the unit operation, easily enhancement of the unit scale, because of module construction and the compact dimensions of the whole system. Apart from these advantages in membrane assisted bioreactor excess sludge production is lower than in conventional activated sludge systems (Ghyoot et al., 2000, Rols et al., 1997), what becomes important on account of the cost connected with treatment of the sludge. COD removal achieves high level and the nitrification of the ammonia nitrogen concentration typical for municipal wastewater is usually complete (Rosenberger et al., 2002, Cicek et al., 2001, Nagaoka et al., 1999). Also progress in wastewater treatment processes takes place. The deammonification process was discovered by scientists few years ago. The deammonification is a process, that compared to conventional nitrification – denitrification, requires considerably smaller amounts of carbon and oxygen. It is the process, which combine partial nitrification with anaerobic ammonium oxidation (ANAMMOX) process in one single reactor or proceeds as a two-step process. This process allows to reduce aeration and eliminate necessity of external carbon source addition to the system.