Characterization of sorption of non-ionic organic compounds on carbon-based nanomaterials
Final Report Abstract
The experimental study of weakly sorbing compounds to materials such as multi-walled carbon nanotubes (MWCNTs) may be challenging due to the limited sorbent to solution ratio. As an alternative, column chromatography was therefore used in this project. Adaptation and modification of a method from literature originally developed for soil materials allowed the reproducible packing of stable columns. Heavy water (D2O) could be identified as only suitable non-retarded tracer after typically used tracers like inorganic anions (e.g. nitrite) showed significant sorption depending on applied eluent conditions. Especially sorption of inorganic anions was not expected to be that strong. For this reason, the RID approved in this project was necessary for the study. The influence of a broad range of environmental conditions (pH, ionic strength, and temperature) was successfully studied on sorption of inorganic compounds (initially expected to be useful non-retarded tracers) and organic compounds to MWCNTs. Heterocyclic organic compounds like pyrazole were hardly studied in literature and weak sorption was expected from prediction models. It could be shown that environmental conditions can strongly influence sorption. The advantages of column chromatography like reduced sorbent demand, higher sorbent to solution ratios, high variability in test conditions, and automation potential could be successfully used and pronounce column chromatography as valuable complementary technique in sorption studies. Furthermore, other sorbent materials than MWCNTs like functionalized MWCNTs, graphene, graphite, and activated carbon could also be studied and compared regarding their sorption properties using the developed column chromatography method allowing the comparison of sorbent materials and effects of for example the surface modification of MWCNTs comparable to batch experiments with strongly reduced sorbent demand. Consequently, this project demonstrates that column chromatography is suitable as complementary technique in sorption studies for carbon-based materials and nanomaterials to study sorption of weakly sorbing compounds and the influence of environmental conditions on their sorption as well as the comparison of different sorbent materials. In future, column chromatography and its benefits could potentially be used for example in studies using plastic materials as sorbent material investigating the influence of these materials on sorption processes in soils and the aqueous environment. Additionally, column chromatography can be used to derive prediction models for varying environmental conditions for diverse carbon-based materials with reduced time and sorbent demand than necessary for batch experiments.
Publications
- Characterization of sorption properties of carbon nanomaterials (CNM) using packed columns and inverse liquid chromatography. 10th International Conference on the Environmental Effects of Nanoparticles and Nanomaterials, 2015, 6. – 10. September, Vienna, Austria
Metzelder, F.; Schmidt, T.C.
- Charakterisierung der Sorptionseigenschaften von Kohlenstoffnanomaterialien mittels gepackter Säulen und inverser Flüssigkeitschromatographie. Jahrestagung der Wasserschemischen Gesellschaft, 2015, 11. – 13. May 2015, Schwerin, Germany
Metzelder, F.; Schmidt, T.C.
- Charakterisierung der Sorptionseigenschaften von Kohlenstoffnanomaterialien mittels gepackter Säulen und inverser Flüssigkeitschromatographie. Phase 2: Untersuchung des Einflusses von Umweltbedingungen. Jahrestagung der Wasserschemischen Gesellschaft, 2016, 2. – 4. Mai 2016, Bamberg, Germany
Metzelder, F.; Schmidt, T.C.
- Kohlenstoffnanoröhren zur chromatographischen Trennung anorganischer Anionen – Konzeptionelle Untersuchung des Materials. 2. Wasseranalytisches Seminar (MWAS), 2016, 14. – 15. September 2016, Mülheim, Germany
Metzelder, F.; Schmidt, T.C.
- Charakterisierung der Sorptionseigenschaften von Kohlenstoffnanomaterialien mittels gepackter Säulen und inverser Flüssigkeitschromatographie. Jahrestagung der Wasserschemischen Gesellschaft, 2017, 22. – 24. Mai 2017, Donaueschingen, Germany
Metzelder, F.; Funck, M.; Schmidt, T.C.
- Environmental conditions influencing sorption of inorganic anions to multiwalled carbon nanotubes studied by column chromatography. Environmental Science & Technology, 2017, 51 (9), 2928 – 2935
Metzelder, F.; Schmidt, T.C.
(See online at https://doi.org/10.1021/acs.est.6b06386) - Comparison of sorption to carbon-based materials and nanomaterials using inverse liquid chromatography. Environmental Science & Technology, 2018, 52(17), 9731 – 9740
Metzelder, F.; Funck, M.; Hüffer, T.; Schmidt, T.C.
(See online at https://doi.org/10.1021/acs.est.8b01653) - Sorption of heterocyclic organic compounds to multiwalled carbon nanotubes. Environmental Science & Technology, 2018, 52 (9), 628 – 637
Metzelder, F.; Funck, M.; Schmidt, T.C.
(See online at https://doi.org/10.1021/acs.est.7b05205) - Untersuchung der Sorption an Kohlenstoffnanomaterialien mittels inverser Flüssigkeitschromatographie. Mitteilungen der Fachgruppe Umweltchemie und Ökotoxikologie, 2018, 1, 6 – 9
Metzelder, F.; Funck, M.; Schmidt, T.C.
