标题：A study of ferric-carbon micro-electrolysis process to enhance nitrogen and phosphorus removal efficiency in subsurface flow constructed wetlands
作者：Shen, Youhao; Zhuang, Linlan; Zhang, Jian; Fan, Jinlin; Yang, Ting; Sun, Shuo
作者机构：[Shen, Youhao; Zhuang, Linlan; Zhang, Jian; Fan, Jinlin] Shandong Univ, Shandong Key Lab Water Pollut Control & Resource, Sch Environm Sci & Engn, Qin 更多
通讯作者：Zhuang, Linlan;Zhuang, LL;Zhang, J
通讯作者地址：[Zhuang, LL; Zhang, J]Shandong Univ, Shandong Key Lab Water Pollut Control & Resource, Sch Environm Sci & Engn, Qingdao 266237, Peoples R China.
来源：CHEMICAL ENGINEERING JOURNAL
关键词：Micro-electrolysis; Denitrification; Nitrogen removal; Phosphorus; removal; Subsurface-flow constructed wetlands
摘要：The application of subsurface-flow constructed wetlands (SSFCWs) has been restricted by the low nitrogen and phosphorus removal efficiency for several decades. Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) system has gained increasing attention due to its high redox capacity and the function of adsorption and flocculation. Therefore, to apply Fe/C-M/E process in SSFCWs is a promising approach to enhance the removal efficiency of nitrogen and phosphorus of domestic sewage. In this study, a micro-electrolysis-intensified subsurface-flow constructed wetlands (ME-SSFCWs) including iron scraps and biochar were operated to investigate the effect of micro-electrolysis-substrate on nitrogen and phosphorus removal performance together with the related kinetics and possible pathways. The results showed that the removal efficiency of NO3--N, total nitrogen (TN) and phosphorus by ME-SSFCWs were 99.54 +/- 0.80%, 81.45 +/- 1.27% and 93.63 +/- 5.30d%, respectively, for a 3-day hydraulic retention time (HRT), which were much higher than that of the ordinary SSFCWs (NO3--N: 37%; TN: 38%; TP: 39%) and biochar-added SSFCWs (NO3--N: 57%; TN: 54%; TP: 21%). These results indicated that micro-electrolysis could supply electrons for the denitrification. Besides, the improvement of phosphorus removal efficiency was due to the galvanic corrosion of numerous micro-scale sacrificial anodes which caused precipitation, adsorption and flocculation of phosphorus. Microbial analysis via real-time quantitative PCR Detecting System (qPCR) revealed that associated microbial abundance could dramatically increase due to the addition of Fe/C-M/E material substrate.