[SCAN] Development of photocatalytic membranes and hybrid reactors for water and wastewater treatment

Title: Development of photocatalytic membranes and hybrid reactors for water and wastewater treatment

Speaker: Vanessa Pereira

Affiliation: iBET/ITQB NOVA

Abstract:

Membrane filtration and ultraviolet (UV) photolysis/titanium dioxide (TiO2) photocatalysis are effective to remove pollutants from wastewater and drinking water sources [e.g.1-3]. However, there are some challenges related with their application: fouling, further treatment/disposal of retentate, formation of toxic UV by-products, and need to remove TiO2 nanoparticles when used in suspension.

Coupling stable photoactive TiO2 layers with water filtration technology can be beneficial to achieve high quality effluents that can be directly discharged in the aquatic environment while retaining by-products, decreasing fouling components and treating the concentrated retentate. Promising photocatalytic membranes were developed combining titanium dioxide, silicon carbide and silicon dioxide [4]. The modified membranes produced have a homogeneous top surface with lower molecular weight cut-off and higher hydrophilicity compared to the unmodified commercial membranes. The modification method was further improved using a solvent free process [5].

Two hybrid photocatalytic membrane reactors were assembled and used to test the photocatalytic membranes developed [6, 7]. High removals of total suspended solids, oil and grease, chemical oxygen demand, total organic carbon and phenolic compounds were obtained when a hybrid photocatalytic membrane reactor that can be easily scaled up was used to treat real olive mill wastewaters [6]. In addition, the photocatalytic membranes produced were found to effectively retain microorganisms, such as bacteria and fungi, that can then be effectively inactivated by photolysis using the hybrid reactors assembled [7]. These membranes and reactors can therefore be a promising approach to treat drinking water and wastewaters produced by different industries.

Keywords: Membrane filtration; ultraviolet radiation; photocatalytic membranes; hybrid reactors; water and wastewater treatment

Acknowledgments

Financial support from Fundação para a Ciência e a Tecnologia - through the project PTDC/EAM-AMB/30989/2017 is gratefully acknowledged. iNOVA4Health - UID/Multi/04462/2013, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement is gratefully acknowledged. Associate Laboratory for Green Chemistry LAQV which is financed by national funds from FCT/MEC (UID/QUI/50006/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265) is gratefully acknowledged.

References

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[4] Huertas, R., Fraga, M., Crespo, J.G., Pereira, V.J. 2017. Sol-Gel Membrane Modification for Enhanced Photocatalytic Activity. Separation and Purification Technology. 180, 69-81.

[5] Huertas, R., Fraga, M., Crespo, J.G., Pereira, V.J. 2019. Solvent Free Process for the Development of Photocatalytic Membranes, Molecules. 24, 4481.

[6] Fraga, M., Huertas, R., Crespo, J.G., Pereira, V.J. 2019. Novel submerged photocatalytic membrane reactor for treatment of olive mill wastewaters, Catalysts. Special Issue Photocatalytic Membrane Reactors. 9(9), 769.

[7] Oliveira, B.R., S. Sanches, R. Huertas, Crespo, M. T. B., Pereira, V.J. 2020. Treatment of a real drinking water matrix spiked with Aspergillus fumigatus using a photocatalytic membrane reactor, Journal of Membrane Science. In Press.