Biological denitrification in a continuous flow membrane reactor

Biological denitrification in a bench-scale continuous flow membrane reacto r has been investigated. The nitrate-laden water treated was separated from the suspended denitrifying culture by a 0.02 mu m average pore diameter me mbrane. Equal pressure was maintained across the membrane and nitrate was r emoved by molecular diffusion through the membrane and into the denitrifyin g culture. A nitrate removal efficiency of approximately 90% or a flux of 4 g NO3--N/m(2)/d of membrane area was achieved with an influent concentrati on of 20 mg/l NO3--N. A mathematical model was developed to approximate sys tem performance. Predicted effluent concentrations for the experiments cond ucted were 5.7, 9.5, 11.7 and 17.6 mg/l NO3--N. The respective measured eff luent concentrations were 2.3, 6.0, 9.0 and 16.0 mg/l NO3--N. (C) 1999 Else vier Science Ltd. All rights reserved.