LAUSR

Abstract This study evaluated the influence of influent surface organic loading (SOL) and aeration mode on nitrogen removal and N2O emission in subsurface wastewater infiltration systems (SWISs). Aeration developed appropriate oxygen conditions, which resulted in high COD, NH4+-N and TN removal and enhanced the abundances of amoA, nxrA, napA, narG, nirS, nirK, qnorB and nosZ under SOL rate of 21.2 and 33.8 g COD/(m2 d) compared to the non-aerated SWIS. N2O emission decreased with influent SOL rate increasing in non-aerated and aerated SWISs. The SWIS with intermittent aeration had a better performance on TN removal and lower N2O emission compared to the SWIS with continuous aeration under the same SOL rate. It could conclude that intermittent aeration is a feasible method to win high influent SOL rate, high TN removal and low N2O emission for SWISs.