Photoreactor based on original catalytic foam-filter for wastewater treatment
Résumé
Water is essential for life on Earth, playing a crucial role in sustaining ecosystems and human health. However, the effectiveness of worldwide treatment processes is frequently inadequate, allowing some contaminants to persist and enter natural environments. This failure contributes to the deterioration of ecosystems and poses significant risks to biodiversity and public health. This work focuses on the development of an economic and realistic catalytic foam-filter activated by UV light to effectively remove contaminants in different types of wastewaters before their release in the environment or for water reuse. Using polydopamine, commercial open-cell polyurethane foams-filters are functionalized via a novel and simple dip-coating method, enabling the grafting of TiO2 on the surface of the foam. The resulting catalytic foam-filter is characterized and its photocatalytic activity is first assessed by studying the mineralization of formic acid (a model pollutant) in photoreactor operated in recirculation mode. The stability and recyclability of the catalytic foam-filter are investigated through multiple cycles of test and its performance is evaluated on a mixture of four highly relevant pollutants (atrazine, trimethoprim, 4-nonylphenol and bisphenol A). The results show that the catalytic coating of the foam-filter is highly stable, enabling a mineralization rate of 90 % of formic acid in 60 min, retaining the same efficiency after 15 cycles of reuse. The catalytic foam-filter is also efficient at removing contaminants from a mixture of pollutants, with removal rates ranging from 75 to 100 %. The reactor was modeled and validated by experimental data, enabling a change of scale. This study provides an initial framework for the use of bio-inspired materials in water treatment processes, with interesting mechanical and catalytic properties.