新型Fe基材料高效高选择性还原废水中NO3-为N2的研究

废水中NO3-去除对于控制总氮排放至关重要。Fe0还原NO3-，操作简单、条件温和，但还原产物主要为NH4+，如何高效、高选择性地将NO3-还原为N2，是亟待解决的难题。本项目拟制备一种新型Fe基材料（Fe0-Cu0-CuFe2O4@CNTs），将NO3-高效还原为NO2-；再利用CuFe2O4光催化活化甲酸产生二氧化碳自由基（CO2•−），将NO2-高选择性还原为N2，以实现NO3-的高效、高选择性还原。研究内容包括：（1）制备新型Fe基材料并探讨其高效还原NO3-为NO2-的调控机制；（2）探讨CuFe2O4光催化活化甲酸形成CO2•−的作用机制，揭示CO2•−高选择性还原NO2-为N2的机理；（3）联合利用新型Fe基材料与CO2•−，高效、高选择性还原NO3-为N2，揭示协同作用机制；（4）探讨焦化废水、垃圾渗滤液中NO3-的去除特性。研究成果将为废水中NO3-的去除提供新方法。

The removal of nitrate plays a key role in controlling the discharge of total nitrogen in wastewater. Zero valent iron (Fe0) is often used to reduce nitrate in wastewater due to its simple operation and mild reaction condition. However, the main reduction product is ammonia,which limits its practical application. The project will develop a novel Fe based materials（Fe0-Cu0-CuFe2O4@CNTs),which can be obtained by a chemical replacement combined with oxidation process for the modification of Fe0 surface. The reduction of nitrate into nitrogen with high efficiency and high selectivity will be realized by the following processes: firstly, nitrate is reduced into nitrite by Fe0-Cu0-CuFe2O4@CNTs with rational structure under suitable reaction conditions; then, nitrite is further reduced into nitrogen by the carbon dioxide radicals (CO2•−), which can be produced by photo-activation of formic acid （HCOOH）with the help of CuFe2O4. The as-prepared Fe0-Cu0-CuFe2O4@CNTs will be applied for the removal of nitrate from simulated and practical wastewater, such as coking wastewater and landfill leachate. This project will mainly investigated the regulation mechanism of selective reduction of nitrate into nitrite by Fe0-Cu0-CuFe2O4@CNTs , the formation mechanism of CO2•− from the photocatalytic activation of formic acid by CuFe2O4 and the reduction mechanism of nitrite into nitrogen by CO2•−, the coupling mechanism and specific synergistic mode of Fe0-Cu0-CuFe2O4@CNTs and CO2•− in the denitrification process.The results of this project will provide a technical support for developing a new technology for the removal of nitrate from wastewater.