钛基纳米微反应器光催化强化Mn(III)氧化水中双酚A的研究

The application of Mn(III) oxidation for bisphenol A removal is vastly restricted by the low conversion rate of Mn(II)/Mn(III) as well as the low utilization efficiency of Mn(III) and consequently the generation of a large amount of manganese sludge. Proper countermeasures are therefore necessary for achieving higher system performance. Herein, a series of novel nanoreactors with spatial separation of co-catalysts will be designed. During the photocatalysis process, the nanoreactors are expected to provide oxidation active site for Mn(II) and to effectively promote the separation of photogenerated charge as well as prolong its lifetime. Mn(II) can be oxidized by the photo-generated holes with high oxidation potential, and consequently the conversion rate of Mn(II)/Mn(III) and the utilization efficiency of Mn(III) will be significantly improved. Furthermore, the soluble Mn(II) will gather in the cavity of the nanoreactors due to the confinement effects and electrostatic force, efficiently reducing the production of manganese sludge. The enhancement effects of the nanoreactors for pollutant removal and the key driving factors will be investigated systematically by using various analytical methods and theoretical calculations. Moreover, the mechanisms of the accelerated Mn(II)/Mn(III) conversion process induced by the nanoreactor will be elucidated. This project is expected to provide useful information for future industrial application of photocatalytic oxidation technology in advanced water treatment.

传统Mn(III)氧化去除双酚A的技术中存在Mn(II)/Mn(III)循环效率和Mn(III)利用率低，氧化过程易产生含锰污泥等问题。提高Mn(III)氧化去除双酚A的效率，同时降低体系的运营成本是本项目的研究核心。本项目拟设计一系列新型钛基纳米微反应器。光催化过程中，该反应器能为Mn(III)氧化体系中的Mn(II)提供氧化位点以及满足其氧化电势的光生空穴，促进Mn(II)/Mn(III)循环从而提高Mn(III)的利用率；此外该反应器能通过“孔道限域”效应和“静电吸附”作用富集溶液中的Mn(II)，从而抑制含锰污泥的产生。本项目拟通过多种分析测试手段及理论计算方法，系统研究该纳米微反应器光催化强化的Mn(III)氧化去除低浓度高风险有机微污染物（双酚A）的增效机理和关键驱动因子，同时揭示光催化纳米反应器促进Mn(II)/Mn(III)循环的干预机制，为该体系处理实际工业废水奠定基础。

双酚A（BPA）对人体和环境具有较大的潜在毒性风险，因此需采用合适的方法进行处理，高级氧化具有适用范围广、绿色清洁、处理效果好的优点。本研究通过水热法、模板法等方式制备了多种光催化纳米反应器并考察了其光催化强化氧化目标有机污染物的性能。利用Mn3O4负载的氮化碳纳米管对水中的典型抗生素进行了有效的光催化修复；考察了不同晶形的二氧化锰/亚硫酸氢盐体系的氧化降解BPA的性能，通过构筑模拟岸滤柱形装置考察其长效氧化性能；利用环糊精对锰氧化物进行改性，系统探讨了反应体系初始pH、供氧条件、阴阳离子等因素影响下催化剂/PMS体系对污染物降解性能的影响；将实际检测到的中间产物与理论相结合，推测可能的反应路径。在本项目的资助下，共发表SCI论文11篇，培养博士研究生1名，硕士研究生8名。本项目取得的研究成果可为全面理解锰基催化剂高级氧化降解BPA等污染物提供依据，为合适条件下设计合成纳米催化材料提供理论基础。