NITRIFYING AND PATHOGENIC BACTERIAL FLUCTUATION DURING NITROGEN REMOVAL FROM WASTEWATER IN ZAKHO CITY/IRAQ

The high concentration of nitrogen (N) compounds in wastewater was found to be creating a reason eutrophication, effect the biodiversity aquatic ecosystems and human health. aim this study is reduce harmful N forms from by biological transforming (BNT) bacteria investigate fluctuation ammonium oxidizing (AOB), nitrite (NOB), pathogenic during process, so compost representative. A sample municipal taken, then subjected treatment process BNT, which subdivided into three stages ammonification, nitrification, denitrification. result revealed that nitrifying were flocculated transformation, like AOB NOB isolated until obtaining colonies nitrification liquid mineral solution Agar-Agar calculated. count 468 CFU/ml 2130 sample. existence coliform bacteria, especially E. coli raises possibility water contamination pathogens cause many serious illnesses human. Therefore, Mac-Conkey agar used for isolation total through BNT because it selective also differentiating specialized growth gram- negative bacteria. Total decreased gradually, before ammonification (556 CFU/ml), after (226 (154 CFU/ml) denitrification (45 have been determined indicated further chemical disinfection chlorination or ozonation required complete sterilization concluded all ecosystem deleterious reduced BNT.