纳米Fe3O4/Fe(VI)协同去除水中典型合成麝香的效能与机理研究

Synthetic musks (SMs), as a group of micropollutants, have been widely detected in the environment and require our serious attention. A key step to control the input of SMs into the environment is advanced treatment of the municipal wastewater. Fe(VI) technology is very promising in treating many micropollutants and is proposed to treat typical SMs spiked in the secondary effluent in this project. However, the selective oxidation of pollutants and the relatively poor coagulation performance of the reduced Fe(III) species limit the removal efficiency. Hence, this proposal focuses on the addition of Fe3O4 into the Fe (VI) system to enhance the oxidation and coagulation abilities. H2O2, as an intermediate product during Fe(VI) reduction, can be catalyzed by Fe3O4 to proceed a Fenton-like reaction. Meanwhile, some magnetic iron oxides, as byproducts of Fe(VI), can be attracted to the Fe3O4 nanoparticles and enhance the settleability of the generated particles. The generation and attenuation of H2O2 in the Fe(VI) system will be studied, and the performance of Fe3O4/Fe(VI) in the removal of PPCPs will be assessed and regulated according to the influencing parameters. Moreover, the mechanism of SMs removal during the Fe3O4/Fe(VI) will be investigated in the respects of oxidation and coagulation. Furthermore, the degradation pathways of SMs will be studied through the instrumental detection and frontier orbital theory. The expected results will further the applications of Fe(VI) in water and wastewater treatment.

合成麝香（SMs）是亟需引起重视的一类环境微污染物，而对市政污水进行深度处理是阻止其进入环境的一个关键环节。高铁酸盐（Fe(VI)）在水体微污染物治理方面已取得重要进展，但也显现出选择性氧化和絮凝效果不佳等不足之处。本项目拟在Fe(VI)体系中投加四氧化三铁（Fe3O4）磁性纳米颗粒，通过其与Fe(VI)还原过程中产生的过氧化氢（H2O2）和磁性铁氧体相互作用，可以原位再构建一个类芬顿体系并提高体系后续的絮凝能力，从而强化二级出水中典型SMs的去除效果。探索Fe(VI)体系中H2O2的生成及衰减规律，研究纳米Fe3O4投加比例和时间等试验条件对类芬顿体系构建的影响；并通过监测相关特征指示参数的变化，揭示纳米Fe3O4/Fe(VI)协同作用的机制；最后结合仪器检测和前线轨道理论，分析SMs的降解产物，阐明SMs的降解途径。本项目所取得的成果将有利于进一步拓展Fe(VI)在环境领域的应用范围。

合成麝香是环境中一类普遍存在的水体微污染物，对环境和生态系统的健康存在潜在的负面影响。高铁酸盐（Fe(VI)）在水体微污染物治理方面已取得重要进展，但在处理部分难降解有机物时也存在选择性氧化的不足。本项目以两种典型合成麝香佳乐麝香（HHCB）和吐纳麝香（AHTN）为主要目标污染物，通过在Fe(VI)氧化处理过程中投加四氧化三铁（Fe3O4）纳米颗粒，使Fe3O4纳米颗粒与Fe(VI)还原过程中产生的过氧化氢相互作用，产生羟基自由基，原位再构建了一个类芬顿体系，从而可以强化对于目标污染物的去除效果。本项目分析了纳米Fe3O4投加比例和时间等试验条件对类芬顿体系构建的影响，研究了Fe3O4/Fe(VI)体系处理HHCB和AHTN的效能，揭示了Fe3O4纳米颗粒与Fe(VI)协同作用的机制，并确定了HHCB和AHTN的部分降解产物和降解途径。研究结果显示，在中性条件下，在废水中投加Fe(VI)反应约1 min后再投加Fe3O4纳米颗粒，使Fe(VI)与Fe3O4纳米颗粒的质量比不超过1:5，可以有效地发挥Fe(VI)与Fe3O4纳米颗粒的协同效应，明显提升对于污染物的去除效果，去除率较Fe(VI)与Fe3O4纳米颗粒单独作用之和可以高出5~10%。此外，本项目拓宽了Fe3O4/Fe(VI)体系的应用范围，将之用于印染废水二级出水深度处理的试验，结果显示该体系同样可以有效提升对印染废水二级出水中有机污染物的去除效果。因此，本项目的研究成果具有一定的工程化应用前景。