Immobilized nanoparticles for oxidative and reductive water treatment
Final Report Abstract
Nowadays the world is facing serious problems with water quality and several technological approaches have been applied to solve these problems. One of the promising approaches is the use of highly reactive nanomaterials for water purification. In recent years, zero-valent iron nanoparticles (NZVI) have been applied in aqueous systems for reductive and oxidative processes and for degradation of pharmaceuticals. However, the full potential of these materials has not yet been reached. One of the main reasons is the tendency of nanoparticles to agglomerate once they are synthesized. Another issue is the toxicity of nanoparticles, which may be discharged to the environment during and after their use. These problems can be solved by immobilization of NZVI on robust solid-phase supports. Therefore, the aim of the project was to produce membranes based on carbon nanotubes as support for the immobilization of iron nanoparticles. The produced materials should be applicable in water purification. In this project, two types of robust electro-active membranes based on carbon nanotubes (CNT) were generated, characterized and used as support for the electrochemical deposition of iron nanoparticles. The reactivity of the produced membranes against micropollutants was checked by the betablocker metoprolol. The CNT membranes with and without iron were used for the sorption and oxidative degradation of micropollutants. Experiments to understand sorption and reaction were performed in pure water and water matrices with a more complex composition. In particular, the electrochemical oxidative degradation of micropollutants on these membranes was studied to understand the catalytic role of iron nanoparticles and to evaluate their performance in advanced oxidative processes. To evaluate the experiments, both the micropollutant removal and the occurrence of transformation products (TPs) were analysed. The catalytic effect of the iron particles cold be shown in oxidative degradation experiments and directly depends on the iron loading. The results obtained in this project indicate that carbon nanotube membranes are an excellent support material for iron nanoparticles with rather interesting sorption and electrochemical properties. The generated membranes present promising properties for water filtration and compound degradation at rather low electrochemical potentials. These membranes have a broad range of applications, e.g. for point-of-use water treatment to remove different types of pollutants. Another possible application area would be in analytical chemistry for the generation or production of analytical standards of TPs for further mass spectral characterization and evaluation of their fate in the environment.
Publications
- Application and characterization of electroactive membranes based on carbon nanotubes and zerovalent iron nanoparticles. Water Research 2017, 108, 78-85
Yanez H, J. E.; Wang, Z.; Lege, S.; Obst, M.; Roehler, S.; Burkhardt, C. J.; Zwiener, C.
(See online at https://doi.org/10.1016/j.watres.2016.10.055)
