Background and objective
Petrochemical industry as well as some other industries is one of the environmental pollution which polluttted wastewater with ammonia nitrogen. The objective of this study was two-step ammonia nitrogen removal from Kermanshah Petrochemical effluent using native bacteria immobilized on granular activated carbon.
This study conducted in continuous mode using two reactors with effective volume of 1.7 l for each reactor. These reactors operated as up-flow and fixed film. Granular activated carbon immobilized with nitrifier and denitrifire bacteria has been used as media. Initial concentrations of ammonia and nitrate (50-200 mg/l) with retention time (1-3 h) at pH 8 and temperature of 28 ± 3 ° C were studied.
Findings:Results showed that with increasing in retention time in both reactors nitrification and denitrification efficiency increased. The maximum nitrification and denitrification rates were 2.69 Kg NH4+/m3.d and 2.49 Kg NO3-/m3.d respectively. Maximum nitrification and denitrification rates occurred at 3h retention time and ammonia and nitrate removal efficiency were achieved 99.5 percent.
This study has been showed that native bacteria immobilized on granular activated carbon and use of that in a continuous up-flow attached-growth reactor for the removal of ammonia has a high efficiency