EVALUATING THE EFFECS OF COD/TP RATIO ON PHOSPHORUS AND NITROGEN REMOVAL IN A LAB-SCALE A2O SYSTEM

Abstract

   The study was carried out to evaluate the effecs of COD/TP ratio on nitrogen and phosphorus removal nitrogen from synthetic wastewater in a lab-scale. The influent COD was prepared at about 350mg/L, while the TP was varied to obtain the COD/TP ratio of 20, 30, 40, and 60. The obtained results showed that when the COD/TP ratio was lower than 30, the TP removal efficiency increased when COD/TP ratio was increased, the TP removal efficiency was varied from 72% to 83%, corresponding to the effluent TP lower than 3.0 mg/L. The COD/TP ratio seemed not affect the COD and TN removal. At all COD/TP ratios, the COD and TN removal efficiencies were achieved at over 93% and 75%, respectively. Based on the observed results, it should be noted that during designing and operating the A2O system, the COD/TP ratio needs to be maintained at a proper ratio to achieve high removal efficiency. 

Keywords: A2O system, COD/TP ratio, nitrogen removal, phosphorus removal, wastewater