纳米合金/BDD电极的制备及定向催化氧化脱氮的研究

有毒有害难降解含氮工业废水处理面临着难以采用生物处理法、N2转化效率低、反应速率低、总氮难以达标等难题。基于BDD电极的电化学氧化具有更高的电流效率和电化学稳定性，是最具有应用前景的技术之一。高级电化学氧化的无选择性使得氨氮氧化产物大部分为硝态氮，氨氮虽被氧化转化但总氮并没有被完全去除。如何将无机氮直接定向转化为氮气，减少氨氮深度氧化为硝态氮，是电化学氧化的技术难题。本项目提出构建一种新颖的纳米合金/BDD电极，通过合金催化剂和BDD电极表面组份的协同调控，调变复合电极表面氧物种的活性和浓度，通过改善亲氧和氧的传递能力，提高催化剂的选择性，将废水中氨氮定向高效催化氧化为N2。利用BDD构建的异质复合电极，被分离的电子能够沿BDD快速传递，提高电流利用效率，从而降低能耗。本项目的开展将为电化学氧化处理含氨氮工业废水提供新材料和新思路，对于解决工业废水达标、水体富营养化等问题都具有重要意义。

There are several big issues on industrial wastewater treatment with high content of nitrogen including difficulty in biodegradation, low in N2 yield, low in reaction rate and high content in total nitrogen becauses much stricter water reclamation requirements need to be fulfilled. The electrochemical technology based on BDD is promising for industrail application due to higher current efficiency and longer lifetime. However, most nitrogens in wastewater were converted to NO3-N since BDD electrode have higher overpotential. The novel BDD electrode modified with nano-alloy catalyst was fabricated for the electrochemical oxidation of ammonia to N2 with highly selectivity and high efficiency. Moreover, direct mineralization of organic compounds can also be achieved because of high concentration of OH radicals on the BDD surface. The separated electrons can be quickly tranferred through BDD owing to the heterogeneous structure, and therefore the energy consumption can be saved. It is signficant for a solution to reach the standard of industrial discharge and to remove the eutrophication, when this project can be applied for the provision of new materials and new ideas on the electrochemical treatment of industrial wastewater.