Gutiérrez Sánchez, PabloÁlvarez Torrellas, SilviaLarriba Martínez, MarcosGil, María VictoriaGarrido Zoido, Juan ManuelGarcía Rodríguez, Juan2024-02-052024-02-052023Gutiérrez-Sánchez, P., Álvarez-Torrellas, S., Larriba, M., Gil, M. V., Garrido-Zoido, J. M., & García, J. (2023). Influence of transition metal-based activating agent on the properties and catalytic activity of sewage sludge-derived catalysts. Insights on mechanism, DFT calculation and degradation pathways. Journal of Molecular Liquids, 381, 121840.0167-732210.1016/j.molliq.2023.121840https://hdl.handle.net/20.500.14352/98753This work has been supported by the Spanish MICINN through the project CATAD3.0 PID2020-116478RB-I00. In addition, the authors thank the financial support from the Comunidad de Madrid (Spain) through the Industrial PhD projects (IND2017/AMB-7720 and IND2019/AMB-17114), REMTAVARES Network (S2018/EMT-4341) and the European Social Fund. MVG also thanks Grant PID2021-125295OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” and the Junta de Extremadura and the European Regional Development Fund (ERDF/FEDER), through Grant No. GR21039. The authors are grateful for the Supercomputer facility LUSITANIA funded by CenitS and the Computaex Foundation.Research studies combining the detailed physicochemical properties' analysis, the catalytic activity in different real aqueous matrices, the proposal of degradation mechanisms and the stability of the intermediates/by-products by means of the Density-functional theory (DFT) are scarce. Therefore, this work gives a step forward in the field of circular economy and the removal of emerging pollutants such as the antibiotic ciprofloxacin, covering all the previously aspects mentioned, using four iron and nickel-based catalysts from two different sewage sludge. Experimental results revealed a significant influence of both the source of the sewage sludge and the activating agent used (iron chloride, nickel chloride and a mixture of both) on the physicochemical properties of the materials and, hence, on their catalytic activity. FTIR studies and chemical composition evidenced that the use of this biomass precursor leads to the generation of a wide variety of functional groups and heteroatoms in the synthesized catalyst structure. Moreover, they showed a combination of Type I-IV isotherms with H3-H4 type hysteresis loops, being mainly mesoporous materials and exhibiting a moderate microporosity except when nickel chloride was used solely as activating agent. The carbonaceous materials reached ciprofloxacin adsorption capacities in the range of 40.4–73.9 mg/g. The use of nickel chloride showed the lowest adsorption contribution and catalytic activity. The bimetallic catalyst (synthesized from a mixture of iron and nickel chloride) showed slightly higher catalytic activity than that found for the iron catalyst, but the metal leaching was also considerably higher. Consequently, the use of iron chloride solely as activating agent seems to be the better alternative, achieving a maximum ciprofloxacin removal around 99.7 % and an iron leaching concentration into the reaction medium of 0.48–0.61 mg/L. The main degradation pathways of ciprofloxacin were proposed according to the detection of LC-MS intermediates and DFT calculation, indicating the most likely areas of attack of reactive species on atoms with a high Fukui index (f0)engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/journal articlehttps://doi.org/10.1016/j.molliq.2023.121840open access66.0AntibioticsCatalyst activityChemical activationChlorine compoundsIron compoundsNickel compoundsReal wastewaterIngeniería química3303 Ingeniería y Tecnología Químicas