Enhanced ammonia nitration by Bio-Electrochemical systems with constructed wetlands.

The insufficient abundance of electron acceptors for ammonia during electron transfer in constructed wetlands (CWs) results in low nitrification rates. This study developed a green, low-carbon CWs enhanced by a bio-electrochemical systems (BESs-CWs) to achieve efficient ammonia (NH-N) removal. Electrode enhancement significantly promoted NH-N removal. Compared with traditional CWs, the average removal efficiency of NH-N in the BESs-CWs increased from 62.9 % to 90.6 %. The intermittent voltage driven by the photovoltaic power system caused minimal plant stress. However, electrode enhancement significantly affected microbial communities involved in short-path nitrification and denitrification within the biofilm. Specifically, the removal rate of NH-N by BESs-CWs under electrode enhancement was increased by 27.7 % compared to traditional CWs, enhancing the electron output of NH-N in the BESs-CWs. This system provides a method of ammonia nitration for CWs under poor electron acceptor conditions.