Environmental Catalysis and Technologies

This research area focuses on developing improved technologies for water characterization, treatment, and desalination, as well as removing pollutants from gaseous and liquid effluents. Advanced oxidation processes (AOPs) allow the removal of organic contaminants by chemical reactions involving very reactive oxidants and include catalytic ozonation, catalytic wet (peroxide) oxidation, persulphate activation and heterogeneous electro and photocatalysis. Carbon-based membranes for water desalination and purification applications, including catalytic membranes for AOPs, were further developed. Different strategies were established to support mono and bimetallic catalysts on macrostructured monoliths, which were then applied for the continuous catalytic reduction of inorganic ions. Integrated technologies for oxidation and reduction of pollutants in water were established for the first time. Concerning air pollution abatement, efficient metal oxide catalysts for the total oxidation of volatile organic compounds (VOCs) and carbon-based catalysts for NO reduction were developed. In water characterization, relevant advances were made in the environmental monitoring and risk assessment. A new research topic on enantioselective analytical tools was started associated with an ERC grant. Two other new research topics were started, one related to the behavior and attenuation of microplastics in environmental compartments and another on Life Cycle Assessment and Sustainability, the latter with a transversal impact on our Group.

The design of carbon-based catalysts for the oxidation of organic compounds in water by different AOPs (CWO; CWPO; Catalytic ozonation) and the combination of TiO2 with nanocarbons (especially CNTs, GO and g-C3N4) for photocatalytic processes are consolidated research areas, but still with many scientific challenges. The main advances in this period were related to their application to different water sources and classes of pollutants and the inactivation of antibiotic-resistant bacteria. Reaction pathways were investigated using various chemical scavengers and/or electron paramagnetic resonance (EPR) spectroscopy. Significant improvements in water and wastewater treatment efficiency were obtained by using combined technologies – integrating physical, chemical, and biological approaches. Two pilot plants were developed in collaboration with an industrial partner and are being used for real-case scenarios.

For VOCs removal, cryptomelane‐type manganese oxide, synthesized by a novel solvent‐free technique, and immobilized on ceramic (cordierite) structured supports presented high catalytic activity and stability. The integration of catalytic ozonation and catalytic reduction processes was studied for the first time as a strategy to perform the simultaneous removal of organic and inorganic pollutants in water. More than 50 organic micropollutants (OMPs) were monitored in different campaigns in rivers, coastal areas and wastewater matrices by solid-phase extraction and liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS). A new research line was opened for the accurate risk assessment of chiral drugs in the environment (28 chiral drugs were monitored in Douro River), and an ERC starting grant (1.5 M€) awarded to Rita Lado is presently running on this subject. We are involved in 2 RRP projects: GIATEX, related to smart water management in Textile industry, and Packaging of the Future, with our contribution to LCA activities.

Major projects in this research area include: