# Removal of emerging pollutants with Cyclodextrins-clay composites

Angel Macia, Pablo Taboada, Alfredo Gonzalez-Perez

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## To cite this version:

Angel Macia, Pablo Taboada, Alfredo Gonzalez-Perez. Removal of emerging pollutants with Cyclodextrins-clay composites. 2023. hal-03924506

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Distributed under a Creative Commons Attribution 4.0 International License
Removal of emerging pollutants with Cyclodextrins-clay composites

Angel Macia<fnref n="1" />*, Pablo Taboada<fnref n="2" />,<fnref n="3" /> and Alfredo Gonzalez-Perez<fnref n="4" />,<fnref n="5" />

**Keywords:** cyclodextrins, clays, emerging pollutants, composites, filters, water

**Summary**

It is recognized that a large variety of the organic compounds contaminating the environment can form inclusion complexes with cyclodextrins resulting in enhanced solubility as mentioned in a recent review on cyclodextrins for environmental biotechnologies [1]. Micelle-clay composites have been used for environmental remediation and for the removal of organic pollutants from water [2-5]. In this research we explore the use of cyclodextrins, known to form inclusion complexes and layers onto negatively charged surfaces when combined with cationic surfactants [6-7], to form a composite with clays using similar protocol to the described for micelle-clay composite preparation by Gonzalez-Perez and Macia [8] for the removal of bacteria from water.

**(a) Purpose or objectives and status of study or research hypothesis**

We work to develop clay-based filters for the removal of key pollutants of emerging concern. We use clay-based composites will be characterization at the Molecular-Scale Biophysics Research Infrastructure (MOSBRI) under the project (MOSBRI 2022-110). This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 101004806. The cyclodextrin-clay composite was prepared according to a protocol described elsewhere for pure micelle-clay composites [5,8].

**(b) Key issue(s) or problem(s) addressed**

Many pollutants of emerging concern are electrically neutral and cannot be absorbed directly in clays without modification. We developed modified clays using cyclodextrins (known to be able to form inclusion complexes with some key pollutants like bisphenol A) for the removal of pollutants from water [1]. We aim to develop cost-effective filters easy to recycle ensuring sustainability.

**(c) Methodology or approach used**

The clay is being modified at different concentrations of cyclodextrins and cationic surfactant that become integral part of the clay by cationic exchange. The modified clay and removal

<footnote n="1">¹ Arcadia AB, Ribevägen 22A, 217 46 Malmö, Sweden</footnote>

<footnote n="2">² Instituto de Materiales, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.</footnote>

<footnote n="3">³ Grupo de Física de Coloides y Polímeros, Departamento de Física de Partículas, Universidad de Santiago de Compostela, 15782-Santiago de Compostela</footnote>

<footnote n="4">⁴ Water Centre for Innovation (Campus Roslagen AB), Kaserngatan 11, 761 46 Norrtälje, Sweden</footnote>

<footnote n="5">⁵ Biocomplexity and Biophysics, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 172100 Copenhagen, Denmark</footnote>

<footnote>* Email: macia@arcadiasolutions.se</footnote>
efficiency is being characterized by different techniques (SAXS, FTIR and UV). The preliminary
test for the removal efficiency was investigated in cooperation with our partners at the
University using Erythromycin and Bisphenol A as a test model pollutant.

(d) Results and conclusions derived from the project

The modified clay is being characterized under the project MOSBRI 2022-110. SAXS experiments will be provided to confirm the optimal cyclodextrin-surfactant concentration to ensure a functional clay modification for the removal of Bisphenol A. Complementary studies are being done using different techniques (FTIR and UV) to assess the removal efficiency of different samples under investigation. The removal capacity of the composite for the model pollutants was superior for the cyclodextrin-clay composite compared with the micelle-clay composite investigated previously.

(e) Policy implications of the project relevant to the selected conference theme, theory and/or practice

We aim to provide a cost-effective filter that can be reused may times for the removal of
small amounts emerging pollutants to maintain clean water bodies and in particular drinking
water. If regulation requires the removal of some pollutants of emerging concern, solutions
will be available at a reasonable price. The preliminary results are shown to be promising and
more systematic work needs to be done to develop a functional filter.

Acknowledgments

We want to acknowledge the MOSBRI network for the project MOSBRI 2022-110, Cyclodextrin-clay composites for the removal of micropollutants (This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 101004806). (https://www.mosbri.eu/).

References

[1] Fenyvesi, É. and Sohajda, T. (2022) Cyclodextrin-enabled green environmental biotechnologies. *Environ Sci Pollut Res Int.* 29(14):20085-20097.

[2] Polubesova, T., et al. (2005) Water purification from organic pollutants by optimized Micelle-clay systems. *Environ. Sci. Technol.* **39**, 2343-2348.

[3] Polubesova, T. et al. (2006) Water remediation by Micelle-clay system: Case study for tetracycline and sulfonamide anti-biotics. *Water Research* **12**, 2369-74.

[4] Nir, S. et al. (2015) Water purification from perchlorate by micelle-clay complex: laboratory and pilot experiments. *Applied Clay Science* **114**, 151-156.

[5] Benitez, A.R. et al. (2022) Modified compositions of micelle-clay and liposome-clay composites for optimal removal from water of bacteria and hydrophobic neutral chemicals. *Applied Sciences* **12**, 3044-.

[6] Gonzalez-Perez, A. and Ruso, JM. (2013) A versatile approach towards compaction, decompaction and immobilization of DNA at interfaces using cyclodextrins. *ChemPhysChem* **14**, 2544-2553.

[7] Gonzalez-Perez, A. (2010) β-Cyclodextrin in DNA decompaction: An imaging approach. *Frontiers in Bioscience E2* (2010) 684-693.

[8] Gonzalez-Perez, A. and Macia, A. (2022) Water disinfection with micelle-clay composites. *IWA 3rd International Conference on Disinfection and DBPs*, Milan, 221-223.