Experimental study of the biological treatment process of the exit wastewater from flocculation reactor

Abstract

This study investigates biological treatment of outlet wastewater from flocculation reactor. This stream has an unpleasant odor. So, a biological treatment unit has been used to separate biological contaminants. Results show that 35 min can be considered as optimum oxygen injection time. Results show that the reduction of nitrate and phosphate is 67% and 60.8% with increasing oxygenation time, respectively. Results show that BOD and COD decrease by about 1.8% and 1% with increasing oxygenation time from 35 to 40 min, respectively. Studies show that organic carbon and petroleum hydrocarbons decrease from 20.1 to 4.8 mg/l and 0.14–0.4 mg/l by increasing oxygen injection time from 5 to 35 min, respectively. Results show that wastewater turbidity decreasing is from 4.3 NTU to 2.1 NTU in biological unit. Results show that range of pH is between 9.9 and 10.4.