Ammonium removal in granular activated carbon up-flow submerged reactors containing native bacterial consortium

Free ammonium in industries wastewater could be one of the worst toxic contaminants of aquatic life if diluted in water. Biological nitrogen removal (BNR) is the most common method for removing ammonium and nitrate from wastewater. Attached growth and suspended growth are the main BNR systems. The aim of the present work was to study the treatment of petrochemical wastewater (ammonium and nitrate removal) using native bacterial consortium isolated from Kermanshah Wastewater Treatment Plant, Iran, in two laboratory-scale high performance, granular activated carbon up-flow submerged reactors (GAC-USRs). The average maximum removal efficiency of NH4-N and NO3-N was 97.46% and 97.58% at the nitrification rate (NR) and denitrification rate (DR) of 2.44 kg NH4-N/m3.day and 2.31 kg NO3-N/m3.day, respectively. It was confirmed that the immobilized native bacterium on GAC could achieve a high ammonium and nitrate removal efficiency. The results of this study showed that the Bio-GAC-USRs can be an efficient method for complete ammonium and nitrate removal from wastewater.