Optimizing vertical flow aerated steel slag filter system with nitrifiers bacteria for nutrients' removal from domestic wastewater: a pilot study

BACKGROUND The present study aimed to optimize the removal efficiency of ammonia nitrogen (NH3‐N) and total kjeldhal nitrogen (TKN) from domestic wastewater as a function of hydraulic loading rates (HLRs) (0.16–5.44 m3 m–3 day–1) and the aeration rate (3, 5 and 10 L min–1) in a vertical flow aerated steel slag filter (VFASSF) system with nitrifier bacteria. The nitrifier bacterial cell morphology was determined using scanning electron microscopy (SEM) analysis. RESULTS The HLRs affected the performance of the VFASSF in removing TKN and NH3‐N from domestic wastewater. The optimal air flow rate for removing NH3‐N and TKN was recorded with 10 L min–1 and HLR 2.72 m3 m–3 day–1, at which the removal efficiency was >91% compared to 90% and 88% with 3 L min–1 and 5 L min–1 air flow rate, respectively. The high removal was a consequence of the high aeration which enhances the nitrification process performed by the nitrifying bacteria in the VFASSF. CONCLUSIONS These findings reflected the applicability of VFASSF in the treatment and removal of nutrients from domestic wastewater. © 2020 Society of Chemical Industry