Introducing and Evaluating a New Model of Rotary Reactor in Nitrate Removal from Aqueous Environments by Electrocoagulation Method

Background & objectives: Nitrate contamination of drinking water is a common problem in many parts of the world that poses a serious threat to public health and environment. In this research, the performance of a new rotary electrocoagulation reactor model for removal of nitrate in presence or absence of turbidity has been investigated. Methods: In this study, aluminum and iron electrodes were analyzed in parallel and monopolar arrangement. At each test time, a sample of 370 liters was prepared and the effects of operating parameters such as initial nitrate concentration, current density, annular reactor speed, optimum time, electrode materials and presence of turbidity on nitrate removal were evaluated. Results: The results indicated that the optimum utilization parameters were material of aluminum electrode, current density of 22.8 A/m2, annular reactor speed of 13.3 rpm and optimum time of 90 min, under which removal efficiency was 95.7%. The presence of turbidity has decreasing effect on nitrate removal and at nitrate concentration of 225 mg and with increasing in turbidity, the removal efficiency decreased from 81% to 48%. For aluminum electrode, the consumed energy in optimum utilization condition was 0.74 kWh/m3. Conclusion: The results of this study showed that the introduced batch rotary reactor model was able to remove the high nitrate content from aquatic environments with ease of use and this model is recommended to be used for drinking water treatment plants.