آب و فاضلاب (Mar 2007)
Inhibitory Effect of Phenol on Ammonia Removal by Nitrification of High Ammonia and Phenol Contaminated Coke Wastewater from Isfahan Steel Company (ISCO)
Abstract
In this study, the nitrification process using enriched ammonia oxidizing bacteria was used for ammonium removal from coke wastewater of Isfahan Steel Company (ISCO). Influent and effluent samples containing ~600 mg l-1 ammonium and 2530-550 mg l-1 phenol were collected. For comparative assessment, ammonia removal was performed on artificial media in which removal of ammonium took a shorter time (8 days) than in the real wastewater. Ammonium removal efficiency from the effluent was higher than that from the influent due to the reduced phenol content in the former. The best result occurred in the treatment composed of effluent, enriched nitrifiers, and bicarbonate for which a record ammonium removal of 14 days was observed. MPN method was used to count and compare colonies of nitrifying bacteria in the samples. The enriched nitrifier sample containing 4.6×103 cell ml-1 was the best. The results show that phenol has inhibitory effects on nitrification. Carbonate ions and enriched nitrifying bacteria have positive effects on ammonium removal in all samples.
