Aiming at the problem of high concentration of total nitrogen(TN) and low available carbon source for microorganisms in municipal secondary effluent,the vertical flow constructed wetland associated with iron-carbon internal electrolysis(ICIE-VFCW) was applied to investigate the removal efficiencies of pollutants in municipal secondary effluent. Moreover,the mechanism for enhanced nitrogen removal was primarily discussed by the applications of UV visible spectrum(UV-VIS) and gel filtration chromatography(GFC...