Negative entropy drive NH4+-N oxidation to N2 and hydrogen ion reduction to H2

This article describes the oxidation of NH4+-N to N2 by functional bacteria on the anode and the reduction of H+ to H2 on the cathode under the input of negative entropy for the first time. When the voltage is 0.3 V, 86.1 % of NH4+-N is converted to N2 and the volume ratio of H2 produced on the cathode and N2 on the anode is 1:2.93. As the voltage increased from 0.3 to 0.5 V, the ratio of NH4+-N oxidation to N2 decreased sharply from 86.1 % to 4.2 %. Anode potential is the key factor affecting the pathway of NH4+-N oxidation by functional microorganism on the anode. The oxidation of NH4+-N on the anode is closely related to functional microorganisms such as PHOSHE36, Anaerolineaceae, Gemmatimonadaceae, Hyphomonadaceae, and Nitrosomonadaceae. The negative entropy input drives the coupling process of NH4+-N oxidation to N2 on the anode and H+ reduction to H2 on the cathode.