An ultraviolet/biological (UV/B) reactor for the removal of nitrogenous compounds from the secondary effluent of wastewater treatment plants (WWTPs)

Abstract

An ultraviolet/biological (UV/B) reactor was used to treat the secondary effluent of wastewater treatment plants (WWTPs). A continuous flow experiment proved that the UV/B reactor could significantly reduce nitrogenous compounds, and the UV/B reactor had a higher removal rate of total nitrogen (TN), nitrate nitrogen (NO₃⁻–N), ammonia nitrogen (NH₄⁺–N), Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) at an UV/biological degradation stage than a biological degradation stage. The effect of hydraulic retention time (HRT), water temperature, pH, and dissolved oxygen (DO) on NO₃⁻–N removal in the UV/B reactor was discussed, and it was found that the HRT and water temperature significantly influenced the NO₃⁻–N removal efficiency, but the effect of pH and DO on NO₃⁻–N removal was not significant.